godot/thirdparty/embree/kernels/bvh/bvh4_factory.cpp

// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0

#include "bvh4_factory.h"
#include "../bvh/bvh.h"

#include "../geometry/curveNv.h"
#include "../geometry/curveNi.h"
#include "../geometry/curveNi_mb.h"
#include "../geometry/linei.h"
#include "../geometry/triangle.h"
#include "../geometry/trianglev.h"
#include "../geometry/trianglev_mb.h"
#include "../geometry/trianglei.h"
#include "../geometry/quadv.h"
#include "../geometry/quadi.h"
#include "../geometry/subdivpatch1.h"
#include "../geometry/object.h"
#include "../geometry/instance.h"
#include "../geometry/instance_array.h"
#include "../geometry/subgrid.h"
#include "../common/accelinstance.h"

namespace embree
{
  DECLARE_SYMBOL2(Accel::Collider,BVH4ColliderUserGeom);

  DECLARE_ISA_FUNCTION(VirtualCurveIntersector*,VirtualCurveIntersector4i,void);
  DECLARE_ISA_FUNCTION(VirtualCurveIntersector*,VirtualCurveIntersector8i,void);
  DECLARE_ISA_FUNCTION(VirtualCurveIntersector*,VirtualCurveIntersector4v,void);
  DECLARE_ISA_FUNCTION(VirtualCurveIntersector*,VirtualCurveIntersector8v,void);
  DECLARE_ISA_FUNCTION(VirtualCurveIntersector*,VirtualCurveIntersector4iMB,void);
  DECLARE_ISA_FUNCTION(VirtualCurveIntersector*,VirtualCurveIntersector8iMB,void);
    
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4OBBVirtualCurveIntersector1);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4OBBVirtualCurveIntersector1MB);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4OBBVirtualCurveIntersectorRobust1);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4OBBVirtualCurveIntersectorRobust1MB);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4Intersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4iIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4vIntersector1Pluecker);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4iIntersector1Pluecker);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4vMBIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4iMBIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4vMBIntersector1Pluecker);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Triangle4iMBIntersector1Pluecker);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Quad4vIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Quad4iIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Quad4vIntersector1Pluecker);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Quad4iIntersector1Pluecker);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Quad4iMBIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4Quad4iMBIntersector1Pluecker);

  DECLARE_SYMBOL2(Accel::Intersector1,QBVH4Triangle4iIntersector1Pluecker);
  DECLARE_SYMBOL2(Accel::Intersector1,QBVH4Quad4iIntersector1Pluecker);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4SubdivPatch1Intersector1);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4SubdivPatch1MBIntersector1);
  
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4VirtualIntersector1);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4VirtualMBIntersector1);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4InstanceIntersector1);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4InstanceMBIntersector1);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4InstanceArrayIntersector1);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4InstanceArrayMBIntersector1);

  DECLARE_SYMBOL2(Accel::Intersector1,BVH4GridIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4GridMBIntersector1Moeller);
  DECLARE_SYMBOL2(Accel::Intersector1,BVH4GridIntersector1Pluecker);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4OBBVirtualCurveIntersector4Hybrid);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4OBBVirtualCurveIntersector4HybridMB);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4OBBVirtualCurveIntersectorRobust4Hybrid);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4OBBVirtualCurveIntersectorRobust4HybridMB);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4Intersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4Intersector4HybridMoellerNoFilter);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4iIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4vIntersector4HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4iIntersector4HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4vMBIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4iMBIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4vMBIntersector4HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Triangle4iMBIntersector4HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Quad4vIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Quad4vIntersector4HybridMoellerNoFilter);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Quad4iIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Quad4vIntersector4HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Quad4iIntersector4HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Quad4iMBIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4Quad4iMBIntersector4HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4SubdivPatch1Intersector4);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4SubdivPatch1MBIntersector4);
  
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4VirtualIntersector4Chunk);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4VirtualMBIntersector4Chunk);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4InstanceIntersector4Chunk);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4InstanceMBIntersector4Chunk);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4InstanceArrayIntersector4Chunk);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4InstanceArrayMBIntersector4Chunk);

  DECLARE_SYMBOL2(Accel::Intersector4,BVH4GridIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4GridMBIntersector4HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector4,BVH4GridIntersector4HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4OBBVirtualCurveIntersector8Hybrid);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4OBBVirtualCurveIntersector8HybridMB);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4OBBVirtualCurveIntersectorRobust8Hybrid);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4OBBVirtualCurveIntersectorRobust8HybridMB);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4Intersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4Intersector8HybridMoellerNoFilter);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4iIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4vIntersector8HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4iIntersector8HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4vMBIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4iMBIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4vMBIntersector8HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Triangle4iMBIntersector8HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Quad4vIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Quad4vIntersector8HybridMoellerNoFilter);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Quad4iIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Quad4vIntersector8HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Quad4iIntersector8HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Quad4iMBIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4Quad4iMBIntersector8HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4SubdivPatch1Intersector8);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4SubdivPatch1MBIntersector8);
  
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4VirtualIntersector8Chunk);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4VirtualMBIntersector8Chunk);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4InstanceIntersector8Chunk);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4InstanceMBIntersector8Chunk);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4InstanceArrayIntersector8Chunk);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4InstanceArrayMBIntersector8Chunk);

  DECLARE_SYMBOL2(Accel::Intersector8,BVH4GridIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4GridMBIntersector8HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector8,BVH4GridIntersector8HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4OBBVirtualCurveIntersector16Hybrid);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4OBBVirtualCurveIntersector16HybridMB);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4OBBVirtualCurveIntersectorRobust16Hybrid);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4OBBVirtualCurveIntersectorRobust16HybridMB);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4Intersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4Intersector16HybridMoellerNoFilter);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4iIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4vIntersector16HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4iIntersector16HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4vMBIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4iMBIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4vMBIntersector16HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Triangle4iMBIntersector16HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Quad4vIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Quad4vIntersector16HybridMoellerNoFilter);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Quad4iIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Quad4vIntersector16HybridPluecker);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Quad4iIntersector16HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Quad4iMBIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4Quad4iMBIntersector16HybridPluecker);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4SubdivPatch1Intersector16);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4SubdivPatch1MBIntersector16);
  
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4VirtualIntersector16Chunk);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4VirtualMBIntersector16Chunk);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4InstanceIntersector16Chunk);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4InstanceMBIntersector16Chunk);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4InstanceArrayIntersector16Chunk);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4InstanceArrayMBIntersector16Chunk);

  DECLARE_SYMBOL2(Accel::Intersector16,BVH4GridIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4GridMBIntersector16HybridMoeller);
  DECLARE_SYMBOL2(Accel::Intersector16,BVH4GridIntersector16HybridPluecker);

  DECLARE_ISA_FUNCTION(Builder*,BVH4BuilderTwoLevelTriangle4MeshSAH,void* COMMA Scene* COMMA bool);
  DECLARE_ISA_FUNCTION(Builder*,BVH4BuilderTwoLevelTriangle4vMeshSAH,void* COMMA Scene* COMMA bool);
  DECLARE_ISA_FUNCTION(Builder*,BVH4BuilderTwoLevelTriangle4iMeshSAH,void* COMMA Scene* COMMA bool);
  DECLARE_ISA_FUNCTION(Builder*,BVH4BuilderTwoLevelQuadMeshSAH,void* COMMA Scene* COMMA bool);
  DECLARE_ISA_FUNCTION(Builder*,BVH4BuilderTwoLevelVirtualSAH,void* COMMA Scene* COMMA bool);
  DECLARE_ISA_FUNCTION(Builder*,BVH4BuilderTwoLevelInstanceSAH,void* COMMA Scene* COMMA Geometry::GTypeMask COMMA bool);
  DECLARE_ISA_FUNCTION(Builder*,BVH4BuilderTwoLevelInstanceArraySAH,void* COMMA Scene* COMMA Geometry::GTypeMask COMMA bool);

  DECLARE_ISA_FUNCTION(Builder*,BVH4Curve4vBuilder_OBB_New,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Curve4iBuilder_OBB_New,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4OBBCurve4iMBBuilder_OBB,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Curve8iBuilder_OBB_New,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4OBBCurve8iMBBuilder_OBB,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4SceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4vSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4iSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4iMBSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4vMBSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4QuantizedTriangle4iSceneBuilderSAH,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4Quad4vSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Quad4iSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Quad4iMBSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4QuantizedQuad4iSceneBuilderSAH,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4SceneBuilderFastSpatialSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4vSceneBuilderFastSpatialSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4iSceneBuilderFastSpatialSAH,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4Quad4vSceneBuilderFastSpatialSAH,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4VirtualSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4VirtualMBSceneBuilderSAH,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4InstanceSceneBuilderSAH,void* COMMA Scene* COMMA Geometry::GTypeMask);
  DECLARE_ISA_FUNCTION(Builder*,BVH4InstanceMBSceneBuilderSAH,void* COMMA Scene* COMMA Geometry::GTypeMask);

  DECLARE_ISA_FUNCTION(Builder*,BVH4InstanceArraySceneBuilderSAH,void* COMMA Scene* COMMA Geometry::GTypeMask);
  DECLARE_ISA_FUNCTION(Builder*,BVH4InstanceArrayMBSceneBuilderSAH,void* COMMA Scene* COMMA Geometry::GTypeMask);

  DECLARE_ISA_FUNCTION(Builder*,BVH4GridSceneBuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4GridMBSceneBuilderSAH,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4SubdivPatch1BuilderSAH,void* COMMA Scene* COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4SubdivPatch1MBBuilderSAH,void* COMMA Scene* COMMA size_t);

  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4MeshRefitSAH,void* COMMA TriangleMesh* COMMA unsigned int COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4vMeshRefitSAH,void* COMMA TriangleMesh* COMMA unsigned int COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Triangle4iMeshRefitSAH,void* COMMA TriangleMesh* COMMA unsigned int COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4Quad4vMeshRefitSAH,void* COMMA QuadMesh* COMMA unsigned int COMMA size_t);
  DECLARE_ISA_FUNCTION(Builder*,BVH4VirtualMeshRefitSAH,void* COMMA UserGeometry* COMMA unsigned int COMMA size_t);

  BVH4Factory::BVH4Factory(int bfeatures, int ifeatures)
  {
    SELECT_SYMBOL_DEFAULT_AVX_AVX2(ifeatures,BVH4ColliderUserGeom);

    selectBuilders(bfeatures);
    selectIntersectors(ifeatures);
  }

  void BVH4Factory::selectBuilders(int features)
  {
    IF_ENABLED_TRIS (SELECT_SYMBOL_DEFAULT_AVX(features,BVH4BuilderTwoLevelTriangle4MeshSAH));
    IF_ENABLED_TRIS (SELECT_SYMBOL_DEFAULT_AVX(features,BVH4BuilderTwoLevelTriangle4iMeshSAH));
    IF_ENABLED_TRIS (SELECT_SYMBOL_DEFAULT_AVX(features,BVH4BuilderTwoLevelTriangle4vMeshSAH));
    IF_ENABLED_QUADS (SELECT_SYMBOL_DEFAULT_AVX(features,BVH4BuilderTwoLevelQuadMeshSAH));
    IF_ENABLED_USER (SELECT_SYMBOL_DEFAULT_AVX(features,BVH4BuilderTwoLevelVirtualSAH));
    IF_ENABLED_INSTANCE (SELECT_SYMBOL_DEFAULT_AVX(features,BVH4BuilderTwoLevelInstanceSAH));
    IF_ENABLED_INSTANCE_ARRAY (SELECT_SYMBOL_DEFAULT_AVX(features,BVH4BuilderTwoLevelInstanceArraySAH));

    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Curve4vBuilder_OBB_New));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Curve4iBuilder_OBB_New));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4OBBCurve4iMBBuilder_OBB));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX(features,BVH4Curve8iBuilder_OBB_New));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX(features,BVH4OBBCurve8iMBBuilder_OBB));

    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4SceneBuilderSAH));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4vSceneBuilderSAH));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4iSceneBuilderSAH));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4iMBSceneBuilderSAH));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4vMBSceneBuilderSAH));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4QuantizedTriangle4iSceneBuilderSAH));

    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Quad4vSceneBuilderSAH));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Quad4iSceneBuilderSAH));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Quad4iMBSceneBuilderSAH));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4QuantizedQuad4iSceneBuilderSAH));

    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4SceneBuilderFastSpatialSAH));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4vSceneBuilderFastSpatialSAH));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Triangle4iSceneBuilderFastSpatialSAH));

    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4Quad4vSceneBuilderFastSpatialSAH));

    IF_ENABLED_USER(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4VirtualSceneBuilderSAH));
    IF_ENABLED_USER(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4VirtualMBSceneBuilderSAH));

    IF_ENABLED_INSTANCE(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4InstanceSceneBuilderSAH));
    IF_ENABLED_INSTANCE(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4InstanceMBSceneBuilderSAH));

    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4InstanceArraySceneBuilderSAH));
    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4InstanceArrayMBSceneBuilderSAH));

    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4GridSceneBuilderSAH));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4GridMBSceneBuilderSAH));

    IF_ENABLED_SUBDIV(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4SubdivPatch1BuilderSAH));
    IF_ENABLED_SUBDIV(SELECT_SYMBOL_DEFAULT_AVX(features,BVH4SubdivPatch1MBBuilderSAH));
  }

  void BVH4Factory::selectIntersectors(int features)
  {
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,VirtualCurveIntersector4i));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,VirtualCurveIntersector8i));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,VirtualCurveIntersector4v));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,VirtualCurveIntersector8v));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,VirtualCurveIntersector4iMB));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,VirtualCurveIntersector8iMB));
    
    /* select intersectors1 */
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersector1));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersector1MB));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust1));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust1MB));
    
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4Triangle4Intersector1Moeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX512(features,BVH4Triangle4iIntersector1Moeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX512(features,BVH4Triangle4vIntersector1Pluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX512(features,BVH4Triangle4iIntersector1Pluecker));

    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4vMBIntersector1Moeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4iMBIntersector1Moeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4vMBIntersector1Pluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4iMBIntersector1Pluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector1Moeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iIntersector1Moeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector1Pluecker));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iIntersector1Pluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iMBIntersector1Pluecker));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iMBIntersector1Moeller));

    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX512(features,QBVH4Triangle4iIntersector1Pluecker));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX512(features,QBVH4Quad4iIntersector1Pluecker));

    IF_ENABLED_SUBDIV(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4SubdivPatch1Intersector1));
    IF_ENABLED_SUBDIV(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4SubdivPatch1MBIntersector1));
    
    IF_ENABLED_USER(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4VirtualIntersector1));
    IF_ENABLED_USER(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4VirtualMBIntersector1));

    IF_ENABLED_INSTANCE(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceIntersector1));
    IF_ENABLED_INSTANCE(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceMBIntersector1));

    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceArrayIntersector1));
    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceArrayMBIntersector1));

    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4GridIntersector1Moeller));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4GridMBIntersector1Moeller))
    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4GridIntersector1Pluecker));

#if defined (EMBREE_RAY_PACKETS)

    /* select intersectors4 */
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersector4Hybrid));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersector4HybridMB));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust4Hybrid));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_DEFAULT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust4HybridMB));

    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4Intersector4HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4Intersector4HybridMoellerNoFilter));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4iIntersector4HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4vIntersector4HybridPluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4iIntersector4HybridPluecker));

    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4vMBIntersector4HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4iMBIntersector4HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4vMBIntersector4HybridPluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Triangle4iMBIntersector4HybridPluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector4HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector4HybridMoellerNoFilter));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iIntersector4HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector4HybridPluecker));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iIntersector4HybridPluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iMBIntersector4HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4iMBIntersector4HybridPluecker));

    IF_ENABLED_SUBDIV(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4SubdivPatch1Intersector4));
    IF_ENABLED_SUBDIV(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4SubdivPatch1MBIntersector4));
    
    IF_ENABLED_USER(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4VirtualIntersector4Chunk));
    IF_ENABLED_USER(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4VirtualMBIntersector4Chunk));

    IF_ENABLED_INSTANCE(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceIntersector4Chunk));
    IF_ENABLED_INSTANCE(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceMBIntersector4Chunk));

    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceArrayIntersector4Chunk));
    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4InstanceArrayMBIntersector4Chunk));

    IF_ENABLED_QUADS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector4HybridMoeller));

    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4GridIntersector4HybridMoeller));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4GridMBIntersector4HybridMoeller));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_DEFAULT_SSE42_AVX_AVX2_AVX512(features,BVH4GridIntersector4HybridPluecker));

    /* select intersectors8 */
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersector8Hybrid));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersector8HybridMB));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust8Hybrid));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust8HybridMB));

    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4Intersector8HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4Intersector8HybridMoellerNoFilter));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4iIntersector8HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4vIntersector8HybridPluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4iIntersector8HybridPluecker));

    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4vMBIntersector8HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4iMBIntersector8HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4vMBIntersector8HybridPluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Triangle4iMBIntersector8HybridPluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector8HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector8HybridMoellerNoFilter));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Quad4iIntersector8HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Quad4vIntersector8HybridPluecker));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Quad4iIntersector8HybridPluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Quad4iMBIntersector8HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4Quad4iMBIntersector8HybridPluecker));

    IF_ENABLED_SUBDIV(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4SubdivPatch1Intersector8));
    IF_ENABLED_SUBDIV(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4SubdivPatch1MBIntersector8));

    IF_ENABLED_USER(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4VirtualIntersector8Chunk));
    IF_ENABLED_USER(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4VirtualMBIntersector8Chunk));

    IF_ENABLED_INSTANCE(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4InstanceIntersector8Chunk));
    IF_ENABLED_INSTANCE(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4InstanceMBIntersector8Chunk));

    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4InstanceArrayIntersector8Chunk));
    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4InstanceArrayMBIntersector8Chunk));

    IF_ENABLED_GRIDS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4GridIntersector8HybridMoeller));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4GridMBIntersector8HybridMoeller));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_INIT_AVX_AVX2_AVX512(features,BVH4GridIntersector8HybridPluecker));

    /* select intersectors16 */
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX512(features,BVH4OBBVirtualCurveIntersector16Hybrid));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX512(features,BVH4OBBVirtualCurveIntersector16HybridMB));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust16Hybrid));
    IF_ENABLED_CURVES_OR_POINTS(SELECT_SYMBOL_INIT_AVX512(features,BVH4OBBVirtualCurveIntersectorRobust16HybridMB));

    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4Intersector16HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4Intersector16HybridMoellerNoFilter));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4iIntersector16HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4vIntersector16HybridPluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4iIntersector16HybridPluecker));

    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4vMBIntersector16HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4iMBIntersector16HybridMoeller));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4vMBIntersector16HybridPluecker));
    IF_ENABLED_TRIS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Triangle4iMBIntersector16HybridPluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Quad4vIntersector16HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Quad4vIntersector16HybridMoellerNoFilter));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Quad4iIntersector16HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Quad4vIntersector16HybridPluecker));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Quad4iIntersector16HybridPluecker));

    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Quad4iMBIntersector16HybridMoeller));
    IF_ENABLED_QUADS(SELECT_SYMBOL_INIT_AVX512(features,BVH4Quad4iMBIntersector16HybridPluecker));

    IF_ENABLED_SUBDIV(SELECT_SYMBOL_INIT_AVX512(features,BVH4SubdivPatch1Intersector16));
    IF_ENABLED_SUBDIV(SELECT_SYMBOL_INIT_AVX512(features,BVH4SubdivPatch1MBIntersector16));
    
    IF_ENABLED_USER(SELECT_SYMBOL_INIT_AVX512(features,BVH4VirtualIntersector16Chunk));
    IF_ENABLED_USER(SELECT_SYMBOL_INIT_AVX512(features,BVH4VirtualMBIntersector16Chunk));

    IF_ENABLED_INSTANCE(SELECT_SYMBOL_INIT_AVX512(features,BVH4InstanceIntersector16Chunk));
    IF_ENABLED_INSTANCE(SELECT_SYMBOL_INIT_AVX512(features,BVH4InstanceMBIntersector16Chunk));

    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_INIT_AVX512(features,BVH4InstanceArrayIntersector16Chunk));
    IF_ENABLED_INSTANCE_ARRAY(SELECT_SYMBOL_INIT_AVX512(features,BVH4InstanceArrayMBIntersector16Chunk));

    IF_ENABLED_GRIDS(SELECT_SYMBOL_INIT_AVX512(features,BVH4GridIntersector16HybridMoeller));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_INIT_AVX512(features,BVH4GridMBIntersector16HybridMoeller));
    IF_ENABLED_GRIDS(SELECT_SYMBOL_INIT_AVX512(features,BVH4GridIntersector16HybridPluecker));

#endif
  }

  Accel::Intersectors BVH4Factory::BVH4OBBVirtualCurveIntersectors(BVH4* bvh, VirtualCurveIntersector* leafIntersector, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.leafIntersector = leafIntersector;
      intersectors.intersector1  = BVH4OBBVirtualCurveIntersector1();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4OBBVirtualCurveIntersector4Hybrid();
      intersectors.intersector8  = BVH4OBBVirtualCurveIntersector8Hybrid();
      intersectors.intersector16 = BVH4OBBVirtualCurveIntersector16Hybrid();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.leafIntersector = leafIntersector;
      intersectors.intersector1  = BVH4OBBVirtualCurveIntersectorRobust1();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4OBBVirtualCurveIntersectorRobust4Hybrid();
      intersectors.intersector8  = BVH4OBBVirtualCurveIntersectorRobust8Hybrid();
      intersectors.intersector16 = BVH4OBBVirtualCurveIntersectorRobust16Hybrid();
#endif
      return intersectors;
    }
    default: assert(false);
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::BVH4OBBVirtualCurveIntersectorsMB(BVH4* bvh, VirtualCurveIntersector* leafIntersector, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.leafIntersector = leafIntersector;
      intersectors.intersector1  = BVH4OBBVirtualCurveIntersector1MB();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4OBBVirtualCurveIntersector4HybridMB();
      intersectors.intersector8  = BVH4OBBVirtualCurveIntersector8HybridMB();
      intersectors.intersector16 = BVH4OBBVirtualCurveIntersector16HybridMB();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.leafIntersector = leafIntersector;
      intersectors.intersector1  = BVH4OBBVirtualCurveIntersectorRobust1MB();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4OBBVirtualCurveIntersectorRobust4HybridMB();
      intersectors.intersector8  = BVH4OBBVirtualCurveIntersectorRobust8HybridMB();
      intersectors.intersector16 = BVH4OBBVirtualCurveIntersectorRobust16HybridMB();
#endif
      return intersectors;
    }
    default: assert(false);
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::BVH4Triangle4Intersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    assert(ivariant == IntersectVariant::FAST);
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1           = BVH4Triangle4Intersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4_filter    = BVH4Triangle4Intersector4HybridMoeller();
    intersectors.intersector4_nofilter  = BVH4Triangle4Intersector4HybridMoellerNoFilter();
    intersectors.intersector8_filter    = BVH4Triangle4Intersector8HybridMoeller();
    intersectors.intersector8_nofilter  = BVH4Triangle4Intersector8HybridMoellerNoFilter();
    intersectors.intersector16_filter   = BVH4Triangle4Intersector16HybridMoeller();
    intersectors.intersector16_nofilter = BVH4Triangle4Intersector16HybridMoellerNoFilter();
#endif
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4Triangle4vIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    assert(ivariant == IntersectVariant::ROBUST);
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4Triangle4vIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4Triangle4vIntersector4HybridPluecker();
    intersectors.intersector8  = BVH4Triangle4vIntersector8HybridPluecker();
    intersectors.intersector16 = BVH4Triangle4vIntersector16HybridPluecker();
#endif
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4Triangle4iIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1  = BVH4Triangle4iIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4Triangle4iIntersector4HybridMoeller();
      intersectors.intersector8  = BVH4Triangle4iIntersector8HybridMoeller();
      intersectors.intersector16 = BVH4Triangle4iIntersector16HybridMoeller();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1  = BVH4Triangle4iIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4Triangle4iIntersector4HybridPluecker();
      intersectors.intersector8  = BVH4Triangle4iIntersector8HybridPluecker();
      intersectors.intersector16 = BVH4Triangle4iIntersector16HybridPluecker();
#endif
      return intersectors;
    }
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::BVH4Triangle4vMBIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1  = BVH4Triangle4vMBIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4Triangle4vMBIntersector4HybridMoeller();
      intersectors.intersector8  = BVH4Triangle4vMBIntersector8HybridMoeller();
      intersectors.intersector16 = BVH4Triangle4vMBIntersector16HybridMoeller();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1  = BVH4Triangle4vMBIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4Triangle4vMBIntersector4HybridPluecker();
      intersectors.intersector8  = BVH4Triangle4vMBIntersector8HybridPluecker();
      intersectors.intersector16 = BVH4Triangle4vMBIntersector16HybridPluecker();
#endif
      return intersectors;
    }
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::BVH4Triangle4iMBIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1  = BVH4Triangle4iMBIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4Triangle4iMBIntersector4HybridMoeller();
      intersectors.intersector8  = BVH4Triangle4iMBIntersector8HybridMoeller();
      intersectors.intersector16 = BVH4Triangle4iMBIntersector16HybridMoeller();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1  = BVH4Triangle4iMBIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4Triangle4iMBIntersector4HybridPluecker();
      intersectors.intersector8  = BVH4Triangle4iMBIntersector8HybridPluecker();
      intersectors.intersector16 = BVH4Triangle4iMBIntersector16HybridPluecker();
#endif
      return intersectors;
    }
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::BVH4Quad4vIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1           = BVH4Quad4vIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4_filter    = BVH4Quad4vIntersector4HybridMoeller();
      intersectors.intersector4_nofilter  = BVH4Quad4vIntersector4HybridMoellerNoFilter();
      intersectors.intersector8_filter    = BVH4Quad4vIntersector8HybridMoeller();
      intersectors.intersector8_nofilter  = BVH4Quad4vIntersector8HybridMoellerNoFilter();
      intersectors.intersector16_filter   = BVH4Quad4vIntersector16HybridMoeller();
      intersectors.intersector16_nofilter = BVH4Quad4vIntersector16HybridMoellerNoFilter();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1  = BVH4Quad4vIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4Quad4vIntersector4HybridPluecker();
      intersectors.intersector8  = BVH4Quad4vIntersector8HybridPluecker();
      intersectors.intersector16 = BVH4Quad4vIntersector16HybridPluecker();
#endif
      return intersectors;
    }
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::BVH4Quad4iIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1 = BVH4Quad4iIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4 = BVH4Quad4iIntersector4HybridMoeller();
      intersectors.intersector8 = BVH4Quad4iIntersector8HybridMoeller();
      intersectors.intersector16= BVH4Quad4iIntersector16HybridMoeller();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1 = BVH4Quad4iIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4 = BVH4Quad4iIntersector4HybridPluecker();
      intersectors.intersector8 = BVH4Quad4iIntersector8HybridPluecker();
      intersectors.intersector16= BVH4Quad4iIntersector16HybridPluecker();
#endif
      return intersectors;
    }
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::BVH4Quad4iMBIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    switch (ivariant) {
    case IntersectVariant::FAST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1 = BVH4Quad4iMBIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4 = BVH4Quad4iMBIntersector4HybridMoeller();
      intersectors.intersector8 = BVH4Quad4iMBIntersector8HybridMoeller();
      intersectors.intersector16= BVH4Quad4iMBIntersector16HybridMoeller();
#endif
      return intersectors;
    }
    case IntersectVariant::ROBUST:
    {
      Accel::Intersectors intersectors;
      intersectors.ptr = bvh;
      intersectors.intersector1 = BVH4Quad4iMBIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4 = BVH4Quad4iMBIntersector4HybridPluecker();
      intersectors.intersector8 = BVH4Quad4iMBIntersector8HybridPluecker();
      intersectors.intersector16= BVH4Quad4iMBIntersector16HybridPluecker();
#endif
      return intersectors;
    }
    }
    return Accel::Intersectors();
  }

  Accel::Intersectors BVH4Factory::QBVH4Triangle4iIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1 = QBVH4Triangle4iIntersector1Pluecker();
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::QBVH4Quad4iIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1 = QBVH4Quad4iIntersector1Pluecker();
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4UserGeometryIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4VirtualIntersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4VirtualIntersector4Chunk();
    intersectors.intersector8  = BVH4VirtualIntersector8Chunk();
    intersectors.intersector16 = BVH4VirtualIntersector16Chunk();
#endif
    intersectors.collider      = BVH4ColliderUserGeom();
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4UserGeometryMBIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4VirtualMBIntersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4VirtualMBIntersector4Chunk();
    intersectors.intersector8  = BVH4VirtualMBIntersector8Chunk();
    intersectors.intersector16 = BVH4VirtualMBIntersector16Chunk();
#endif
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4InstanceIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4InstanceIntersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4InstanceIntersector4Chunk();
    intersectors.intersector8  = BVH4InstanceIntersector8Chunk();
    intersectors.intersector16 = BVH4InstanceIntersector16Chunk();
#endif
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4InstanceMBIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4InstanceMBIntersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4InstanceMBIntersector4Chunk();
    intersectors.intersector8  = BVH4InstanceMBIntersector8Chunk();
    intersectors.intersector16 = BVH4InstanceMBIntersector16Chunk();
#endif
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4InstanceArrayIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4InstanceArrayIntersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4InstanceArrayIntersector4Chunk();
    intersectors.intersector8  = BVH4InstanceArrayIntersector8Chunk();
    intersectors.intersector16 = BVH4InstanceArrayIntersector16Chunk();
#endif
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4InstanceArrayMBIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4InstanceArrayMBIntersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4InstanceArrayMBIntersector4Chunk();
    intersectors.intersector8  = BVH4InstanceArrayMBIntersector8Chunk();
    intersectors.intersector16 = BVH4InstanceArrayMBIntersector16Chunk();
#endif
    return intersectors;
  }
  
  Accel::Intersectors BVH4Factory::BVH4SubdivPatch1Intersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4SubdivPatch1Intersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4SubdivPatch1Intersector4();
    intersectors.intersector8  = BVH4SubdivPatch1Intersector8();
    intersectors.intersector16 = BVH4SubdivPatch1Intersector16();
#endif
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4SubdivPatch1MBIntersectors(BVH4* bvh)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4SubdivPatch1MBIntersector1();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4SubdivPatch1MBIntersector4();
    intersectors.intersector8  = BVH4SubdivPatch1MBIntersector8();
    intersectors.intersector16 = BVH4SubdivPatch1MBIntersector16();
#endif
    return intersectors;
  }

  Accel* BVH4Factory::BVH4OBBVirtualCurve4i(Scene* scene, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Curve4i::type,scene);
    Accel::Intersectors intersectors = BVH4OBBVirtualCurveIntersectors(accel,VirtualCurveIntersector4i(),ivariant);

    Builder* builder = nullptr;
    if      (scene->device->hair_builder == "default"     ) builder = BVH4Curve4iBuilder_OBB_New(accel,scene,0);
    else if (scene->device->hair_builder == "sah"         ) builder = BVH4Curve4iBuilder_OBB_New(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->hair_builder+" for BVH4OBB<VirtualCurve4i>");

    return new AccelInstance(accel,builder,intersectors);
  }

#if defined(EMBREE_TARGET_SIMD8)
  Accel* BVH4Factory::BVH4OBBVirtualCurve8i(Scene* scene, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Curve8i::type,scene);
    Accel::Intersectors intersectors = BVH4OBBVirtualCurveIntersectors(accel,VirtualCurveIntersector8i(),ivariant);

    Builder* builder = nullptr;
    if      (scene->device->hair_builder == "default"     ) builder = BVH4Curve8iBuilder_OBB_New(accel,scene,0);
    else if (scene->device->hair_builder == "sah"         ) builder = BVH4Curve8iBuilder_OBB_New(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->hair_builder+" for BVH4OBB<VirtualCurve8i>");

    return new AccelInstance(accel,builder,intersectors);
  }
#endif

  Accel* BVH4Factory::BVH4OBBVirtualCurve4v(Scene* scene, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Curve4v::type,scene);
    Accel::Intersectors intersectors = BVH4OBBVirtualCurveIntersectors(accel,VirtualCurveIntersector4v(),ivariant);

    Builder* builder = nullptr;
    if      (scene->device->hair_builder == "default"     ) builder = BVH4Curve4vBuilder_OBB_New(accel,scene,0);
    else if (scene->device->hair_builder == "sah"         ) builder = BVH4Curve4vBuilder_OBB_New(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->hair_builder+" for BVH4OBB<VirtualCurve4v>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4OBBVirtualCurve4iMB(Scene* scene, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Curve4iMB::type,scene);
    Accel::Intersectors intersectors = BVH4OBBVirtualCurveIntersectorsMB(accel,VirtualCurveIntersector4iMB(),ivariant);

    Builder* builder = nullptr;
    if      (scene->device->hair_builder == "default"     ) builder = BVH4OBBCurve4iMBBuilder_OBB(accel,scene,0);
    else if (scene->device->hair_builder == "sah"         ) builder = BVH4OBBCurve4iMBBuilder_OBB(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->hair_builder+" for BVH4OBB<VirtualCurve4iMB>");

    return new AccelInstance(accel,builder,intersectors);
  }

#if defined(EMBREE_TARGET_SIMD8)
  Accel* BVH4Factory::BVH4OBBVirtualCurve8iMB(Scene* scene, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Curve8iMB::type,scene);
    Accel::Intersectors intersectors = BVH4OBBVirtualCurveIntersectorsMB(accel,VirtualCurveIntersector8iMB(), ivariant);

    Builder* builder = nullptr;
    if      (scene->device->hair_builder == "default"     ) builder = BVH4OBBCurve8iMBBuilder_OBB(accel,scene,0);
    else if (scene->device->hair_builder == "sah"         ) builder = BVH4OBBCurve8iMBBuilder_OBB(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->hair_builder+" for BVH4OBB<VirtualCurve8iMB>");

    return new AccelInstance(accel,builder,intersectors);
  }
#endif
  
  Accel* BVH4Factory::BVH4Triangle4(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Triangle4::type,scene);

    Accel::Intersectors intersectors;
    if      (scene->device->tri_traverser == "default") intersectors = BVH4Triangle4Intersectors(accel,ivariant);
    else if (scene->device->tri_traverser == "fast"   ) intersectors = BVH4Triangle4Intersectors(accel,IntersectVariant::FAST);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown traverser "+scene->device->tri_traverser+" for BVH4<Triangle4>");

    Builder* builder = nullptr;
    if (scene->device->tri_builder == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Triangle4SceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : builder = BVH4BuilderTwoLevelTriangle4MeshSAH(accel,scene,false); break;
      case BuildVariant::HIGH_QUALITY: builder = BVH4Triangle4SceneBuilderFastSpatialSAH(accel,scene,0); break;
      }
    }
    else if (scene->device->tri_builder == "sah"         ) builder = BVH4Triangle4SceneBuilderSAH(accel,scene,0);
    else if (scene->device->tri_builder == "sah_fast_spatial" ) builder = BVH4Triangle4SceneBuilderFastSpatialSAH(accel,scene,0);
    else if (scene->device->tri_builder == "sah_presplit") builder = BVH4Triangle4SceneBuilderSAH(accel,scene,MODE_HIGH_QUALITY);
    else if (scene->device->tri_builder == "dynamic"     ) builder = BVH4BuilderTwoLevelTriangle4MeshSAH(accel,scene,false);
    else if (scene->device->tri_builder == "morton"      ) builder = BVH4BuilderTwoLevelTriangle4MeshSAH(accel,scene,true);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->tri_builder+" for BVH4<Triangle4>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Triangle4v(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Triangle4v::type,scene);

    Accel::Intersectors intersectors;
    if      (scene->device->tri_traverser == "default") intersectors = BVH4Triangle4vIntersectors(accel,ivariant);
    else if (scene->device->tri_traverser == "fast"   ) intersectors = BVH4Triangle4vIntersectors(accel,IntersectVariant::FAST);
    else if (scene->device->tri_traverser == "robust" ) intersectors = BVH4Triangle4vIntersectors(accel,IntersectVariant::ROBUST);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown traverser "+scene->device->tri_traverser+" for BVH4<Triangle4>");

    Builder* builder = nullptr;
    if (scene->device->tri_builder == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Triangle4vSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : builder = BVH4BuilderTwoLevelTriangle4vMeshSAH(accel,scene,false); break;
      case BuildVariant::HIGH_QUALITY: builder = BVH4Triangle4vSceneBuilderFastSpatialSAH(accel,scene,0); break;
      }
    }
    else if (scene->device->tri_builder == "sah"         ) builder = BVH4Triangle4vSceneBuilderSAH(accel,scene,0);
    else if (scene->device->tri_builder == "sah_fast_spatial" ) builder = BVH4Triangle4vSceneBuilderFastSpatialSAH(accel,scene,0);
    else if (scene->device->tri_builder == "sah_presplit") builder = BVH4Triangle4vSceneBuilderSAH(accel,scene,MODE_HIGH_QUALITY);
    else if (scene->device->tri_builder == "dynamic"     ) builder = BVH4BuilderTwoLevelTriangle4vMeshSAH(accel,scene,false);
    else if (scene->device->tri_builder == "morton"      ) builder = BVH4BuilderTwoLevelTriangle4vMeshSAH(accel,scene,true);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->tri_builder+" for BVH4<Triangle4v>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Triangle4i(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Triangle4i::type,scene);

    Accel::Intersectors intersectors;
    if      (scene->device->tri_traverser == "default") intersectors = BVH4Triangle4iIntersectors(accel,ivariant);
    else if (scene->device->tri_traverser == "fast"   ) intersectors = BVH4Triangle4iIntersectors(accel,IntersectVariant::FAST);
    else if (scene->device->tri_traverser == "robust" ) intersectors = BVH4Triangle4iIntersectors(accel,IntersectVariant::ROBUST);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown traverser "+scene->device->tri_traverser+" for BVH4<Triangle4i>");

    Builder* builder = nullptr;
    if (scene->device->tri_builder == "default"     ) {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Triangle4iSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : builder = BVH4BuilderTwoLevelTriangle4iMeshSAH(accel,scene,false); break;
      case BuildVariant::HIGH_QUALITY: builder = BVH4Triangle4iSceneBuilderFastSpatialSAH(accel,scene,0); break;
      }
    }
    else if (scene->device->tri_builder == "sah"         ) builder = BVH4Triangle4iSceneBuilderSAH(accel,scene,0);
    else if (scene->device->tri_builder == "sah_fast_spatial" ) builder = BVH4Triangle4iSceneBuilderFastSpatialSAH(accel,scene,0);
    else if (scene->device->tri_builder == "sah_presplit") builder = BVH4Triangle4iSceneBuilderSAH(accel,scene,MODE_HIGH_QUALITY);
    else if (scene->device->tri_builder == "dynamic"     ) builder = BVH4BuilderTwoLevelTriangle4iMeshSAH(accel,scene,false);
    else if (scene->device->tri_builder == "morton"      ) builder = BVH4BuilderTwoLevelTriangle4iMeshSAH(accel,scene,true);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->tri_builder+" for BVH4<Triangle4i>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Triangle4iMB(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Triangle4i::type,scene);

    Accel::Intersectors intersectors;
    if      (scene->device->tri_traverser_mb == "default") intersectors = BVH4Triangle4iMBIntersectors(accel,ivariant);
    else if (scene->device->tri_traverser_mb == "fast"   ) intersectors = BVH4Triangle4iMBIntersectors(accel,IntersectVariant::FAST);
    else if (scene->device->tri_traverser_mb == "robust" ) intersectors = BVH4Triangle4iMBIntersectors(accel,IntersectVariant::ROBUST);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown traverser "+scene->device->tri_traverser_mb+" for BVH4<Triangle4iMB>");

    Builder* builder = nullptr;
    if (scene->device->tri_builder_mb == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Triangle4iMBSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : assert(false); break; // FIXME: implement
      case BuildVariant::HIGH_QUALITY: assert(false); break;
      }
    }
    else  if (scene->device->tri_builder_mb == "internal_time_splits") builder = BVH4Triangle4iMBSceneBuilderSAH(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->tri_builder_mb+" for BVH4<Triangle4iMB>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Triangle4vMB(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Triangle4vMB::type,scene);

    Accel::Intersectors intersectors;
    if      (scene->device->tri_traverser_mb == "default") intersectors = BVH4Triangle4vMBIntersectors(accel,ivariant);
    else if (scene->device->tri_traverser_mb == "fast"   ) intersectors = BVH4Triangle4vMBIntersectors(accel,IntersectVariant::FAST);
    else if (scene->device->tri_traverser_mb == "robust" ) intersectors = BVH4Triangle4vMBIntersectors(accel,IntersectVariant::ROBUST);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown traverser "+scene->device->tri_traverser_mb+" for BVH4<Triangle4vMB>");

    Builder* builder = nullptr;
    if (scene->device->tri_builder_mb == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Triangle4vMBSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : assert(false); break; // FIXME: implement
      case BuildVariant::HIGH_QUALITY: assert(false); break;
      }
    }
    else  if (scene->device->tri_builder_mb == "internal_time_splits") builder = BVH4Triangle4vMBSceneBuilderSAH(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->tri_builder_mb+" for BVH4<Triangle4vMB>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Quad4v(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Quad4v::type,scene);
    Accel::Intersectors intersectors = BVH4Quad4vIntersectors(accel,ivariant);

    Builder* builder = nullptr;
    if (scene->device->quad_builder == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Quad4vSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : builder = BVH4BuilderTwoLevelQuadMeshSAH(accel,scene,false); break;
      case BuildVariant::HIGH_QUALITY: builder = BVH4Quad4vSceneBuilderFastSpatialSAH(accel,scene,0); break;
      }
    }
    else if (scene->device->quad_builder == "sah"              ) builder = BVH4Quad4vSceneBuilderSAH(accel,scene,0);
    else if (scene->device->quad_builder == "sah_fast_spatial" ) builder = BVH4Quad4vSceneBuilderFastSpatialSAH(accel,scene,0);
    else if (scene->device->quad_builder == "dynamic"          ) builder = BVH4BuilderTwoLevelQuadMeshSAH(accel,scene,false);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->quad_builder+" for BVH4<Quad4v>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Quad4i(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Quad4i::type,scene);
    Accel::Intersectors intersectors = BVH4Quad4iIntersectors(accel,ivariant);

    Builder* builder = nullptr;
    if (scene->device->quad_builder == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Quad4iSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : assert(false); break; // FIXME: implement
      case BuildVariant::HIGH_QUALITY: assert(false); break; // FIXME: implement
      }
    }
    else if (scene->device->quad_builder == "sah") builder = BVH4Quad4iSceneBuilderSAH(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->quad_builder+" for BVH4<Quad4i>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Quad4iMB(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(Quad4i::type,scene);
    Accel::Intersectors intersectors = BVH4Quad4iMBIntersectors(accel,ivariant);

    Builder* builder = nullptr;
    if (scene->device->quad_builder_mb == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4Quad4iMBSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : assert(false); break; // FIXME: implement
      case BuildVariant::HIGH_QUALITY: assert(false); break;
      }
    }
    else if (scene->device->quad_builder_mb == "sah") builder = BVH4Quad4iMBSceneBuilderSAH(accel,scene,0);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->quad_builder_mb+" for BVH4<Quad4iMB>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4QuantizedQuad4i(Scene* scene)
  {
    BVH4* accel = new BVH4(Quad4i::type,scene);
    Builder* builder = BVH4QuantizedQuad4iSceneBuilderSAH(accel,scene,0);
    Accel::Intersectors intersectors = QBVH4Quad4iIntersectors(accel);
    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4QuantizedTriangle4i(Scene* scene)
  {
    BVH4* accel = new BVH4(Triangle4i::type,scene);
    Builder* builder = BVH4QuantizedTriangle4iSceneBuilderSAH(accel,scene,0);
    Accel::Intersectors intersectors = QBVH4Triangle4iIntersectors(accel);
    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4SubdivPatch1(Scene* scene)
  {
    BVH4* accel = new BVH4(SubdivPatch1::type,scene);
    Accel::Intersectors intersectors = BVH4SubdivPatch1Intersectors(accel);
    Builder* builder = BVH4SubdivPatch1BuilderSAH(accel,scene,0);
    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4SubdivPatch1MB(Scene* scene)
  {
    BVH4* accel = new BVH4(SubdivPatch1::type,scene);
    Accel::Intersectors intersectors = BVH4SubdivPatch1MBIntersectors(accel);
    Builder* builder = BVH4SubdivPatch1MBBuilderSAH(accel,scene,0);
    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4UserGeometry(Scene* scene, BuildVariant bvariant)
  {
    BVH4* accel = new BVH4(Object::type,scene);
    Accel::Intersectors intersectors = BVH4UserGeometryIntersectors(accel);

    Builder* builder = nullptr;
    if (scene->device->object_builder == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4VirtualSceneBuilderSAH(accel,scene,0); break;
      case BuildVariant::DYNAMIC     : builder = BVH4BuilderTwoLevelVirtualSAH(accel,scene,false); break;
      case BuildVariant::HIGH_QUALITY: assert(false); break;
      }
    }
    else if (scene->device->object_builder == "sah") builder = BVH4VirtualSceneBuilderSAH(accel,scene,0);
    else if (scene->device->object_builder == "dynamic") builder = BVH4BuilderTwoLevelVirtualSAH(accel,scene,false);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->object_builder+" for BVH4<Object>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4UserGeometryMB(Scene* scene)
  {
    BVH4* accel = new BVH4(Object::type,scene);
    Accel::Intersectors intersectors = BVH4UserGeometryMBIntersectors(accel);
    Builder* builder = BVH4VirtualMBSceneBuilderSAH(accel,scene,0);
    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4Instance(Scene* scene, bool isExpensive, BuildVariant bvariant)
  {
    BVH4* accel = new BVH4(InstancePrimitive::type,scene);
    Accel::Intersectors intersectors = BVH4InstanceIntersectors(accel);
    auto gtype = isExpensive ? Geometry::MTY_INSTANCE_EXPENSIVE : Geometry::MTY_INSTANCE_CHEAP;
    // Builder* builder = BVH4InstanceSceneBuilderSAH(accel,scene,gtype);

    Builder* builder = nullptr;
    if (scene->device->object_builder == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4InstanceSceneBuilderSAH(accel,scene,gtype); break;
      case BuildVariant::DYNAMIC     : builder = BVH4BuilderTwoLevelInstanceSAH(accel,scene,gtype,false); break;
      case BuildVariant::HIGH_QUALITY: assert(false); break;
      }
    }
    else if (scene->device->object_builder == "sah") builder = BVH4InstanceSceneBuilderSAH(accel,scene,gtype);
    else if (scene->device->object_builder == "dynamic") builder = BVH4BuilderTwoLevelInstanceSAH(accel,scene,gtype,false);
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->object_builder+" for BVH4<Object>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4InstanceMB(Scene* scene, bool isExpensive)
  {
    BVH4* accel = new BVH4(InstancePrimitive::type,scene);
    Accel::Intersectors intersectors = BVH4InstanceMBIntersectors(accel);
    auto gtype = isExpensive ? Geometry::MTY_INSTANCE_EXPENSIVE : Geometry::MTY_INSTANCE_CHEAP;
    Builder* builder = BVH4InstanceMBSceneBuilderSAH(accel,scene,gtype);
    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4InstanceArray(Scene* scene, BuildVariant bvariant)
  {
    BVH4* accel = new BVH4(InstanceArrayPrimitive::type,scene);
    Accel::Intersectors intersectors = BVH4InstanceArrayIntersectors(accel);
    auto gtype = Geometry::MTY_INSTANCE_ARRAY;

    Builder* builder = nullptr;
    if (scene->device->object_builder == "default") {
      switch (bvariant) {
      case BuildVariant::STATIC      : builder = BVH4InstanceArraySceneBuilderSAH(accel,scene,gtype); break;
      case BuildVariant::DYNAMIC     : builder = BVH4BuilderTwoLevelInstanceArraySAH(accel,scene,gtype,false); break;
      case BuildVariant::HIGH_QUALITY: assert(false); break;
      }
    }
    else if (scene->device->object_builder == "sah") { builder = BVH4InstanceArraySceneBuilderSAH(accel,scene,gtype); }
    else if (scene->device->object_builder == "dynamic") { builder = BVH4BuilderTwoLevelInstanceArraySAH(accel,scene,gtype,false); }
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->object_builder+" for BVH4<Object>");

    return new AccelInstance(accel,builder,intersectors);
  }

  Accel* BVH4Factory::BVH4InstanceArrayMB(Scene* scene)
  {
    BVH4* accel = new BVH4(InstanceArrayPrimitive::type,scene);
    Accel::Intersectors intersectors = BVH4InstanceArrayMBIntersectors(accel);
    Builder* builder = BVH4InstanceArrayMBSceneBuilderSAH(accel,scene,Geometry::MTY_INSTANCE_ARRAY);
    return new AccelInstance(accel,builder,intersectors);
  }

  Accel::Intersectors BVH4Factory::BVH4GridIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    if (ivariant == IntersectVariant::FAST)
    {
      intersectors.intersector1  = BVH4GridIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4GridIntersector4HybridMoeller();
      intersectors.intersector8  = BVH4GridIntersector8HybridMoeller();
      intersectors.intersector16 = BVH4GridIntersector16HybridMoeller();
#endif
    }
    else /* if (ivariant == IntersectVariant::ROBUST) */
    {
      intersectors.intersector1  = BVH4GridIntersector1Pluecker();
#if defined (EMBREE_RAY_PACKETS)
      intersectors.intersector4  = BVH4GridIntersector4HybridPluecker();
      intersectors.intersector8  = BVH4GridIntersector8HybridPluecker();
      intersectors.intersector16 = BVH4GridIntersector16HybridPluecker();
#endif      
    }
    return intersectors;
  }

  Accel::Intersectors BVH4Factory::BVH4GridMBIntersectors(BVH4* bvh, IntersectVariant ivariant)
  {
    Accel::Intersectors intersectors;
    intersectors.ptr = bvh;
    intersectors.intersector1  = BVH4GridMBIntersector1Moeller();
#if defined (EMBREE_RAY_PACKETS)
    intersectors.intersector4  = BVH4GridMBIntersector4HybridMoeller();
    intersectors.intersector8  = BVH4GridMBIntersector8HybridMoeller();
    intersectors.intersector16 = BVH4GridMBIntersector16HybridMoeller();
#endif
    return intersectors;
  }

  Accel* BVH4Factory::BVH4Grid(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(SubGridQBVH4::type,scene);
    Accel::Intersectors intersectors = BVH4GridIntersectors(accel,ivariant);

    Builder* builder = nullptr;
    if (scene->device->object_builder == "default") {
      builder = BVH4GridSceneBuilderSAH(accel,scene,0);
    }
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->grid_builder+" for BVH4<GridMesh>");
    
    return new AccelInstance(accel,builder,intersectors);    
  }

  Accel* BVH4Factory::BVH4GridMB(Scene* scene, BuildVariant bvariant, IntersectVariant ivariant)
  {
    BVH4* accel = new BVH4(SubGridQBVH4::type,scene);
    Accel::Intersectors intersectors = BVH4GridMBIntersectors(accel,ivariant);
    Builder* builder = nullptr;
    if (scene->device->object_builder == "default") {
      builder = BVH4GridMBSceneBuilderSAH(accel,scene,0);
    }
    else throw_RTCError(RTC_ERROR_INVALID_ARGUMENT,"unknown builder "+scene->device->grid_builder+" for BVH4MB<GridMesh>");
    return new AccelInstance(accel,builder,intersectors);        
  }

}