Torque3D/Engine/lib/assimp/code/glTF/glTFImporter.cpp

/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2019, assimp team


All rights reserved.

Redistribution and use of this software in source and binary forms,
with or without modification, are permitted provided that the
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* Redistributions of source code must retain the above
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following disclaimer.

* Redistributions in binary form must reproduce the above
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contributors may be used to endorse or promote products
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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*/

#ifndef ASSIMP_BUILD_NO_GLTF_IMPORTER

#include "glTF/glTFImporter.h"
#include "glTF/glTFAsset.h"
#include "glTF/glTFAssetWriter.h"
#include "PostProcessing/MakeVerboseFormat.h"

#include <assimp/StringComparison.h>
#include <assimp/StringUtils.h>
#include <assimp/Importer.hpp>
#include <assimp/scene.h>
#include <assimp/ai_assert.h>
#include <assimp/DefaultLogger.hpp>
#include <assimp/importerdesc.h>

#include <memory>

using namespace Assimp;
using namespace glTF;

//
// glTFImporter
//

static const aiImporterDesc desc = {
    "glTF Importer",
    "",
    "",
    "",
    aiImporterFlags_SupportTextFlavour | aiImporterFlags_SupportBinaryFlavour | aiImporterFlags_SupportCompressedFlavour
        | aiImporterFlags_LimitedSupport | aiImporterFlags_Experimental,
    0,
    0,
    0,
    0,
    "gltf glb"
};

glTFImporter::glTFImporter()
: BaseImporter()
, meshOffsets()
, embeddedTexIdxs()
, mScene( nullptr ) {
    // empty
}

glTFImporter::~glTFImporter() {
    // empty
}

const aiImporterDesc* glTFImporter::GetInfo() const {
    return &desc;
}

bool glTFImporter::CanRead(const std::string& pFile, IOSystem* pIOHandler, bool /* checkSig */) const {
    const std::string &extension = GetExtension(pFile);

    if (extension != "gltf" && extension != "glb") {
        return false;
    }

    if (pIOHandler) {
        glTF::Asset asset(pIOHandler);
        try {
            asset.Load(pFile, extension == "glb");
            std::string version = asset.asset.version;
            return !version.empty() && version[0] == '1';
        } catch (...) {
            return false;
        }
    }

    return false;
}

inline
void SetMaterialColorProperty(std::vector<int>& embeddedTexIdxs, Asset& /*r*/, glTF::TexProperty prop, aiMaterial* mat,
        aiTextureType texType, const char* pKey, unsigned int type, unsigned int idx) {
    if (prop.texture) {
        if (prop.texture->source) {
            aiString uri(prop.texture->source->uri);

            int texIdx = embeddedTexIdxs[prop.texture->source.GetIndex()];
            if (texIdx != -1) { // embedded
                // setup texture reference string (copied from ColladaLoader::FindFilenameForEffectTexture)
                uri.data[0] = '*';
                uri.length = 1 + ASSIMP_itoa10(uri.data + 1, MAXLEN - 1, texIdx);
            }

            mat->AddProperty(&uri, _AI_MATKEY_TEXTURE_BASE, texType, 0);
        }
    } else {
        aiColor4D col;
        CopyValue(prop.color, col);
        mat->AddProperty(&col, 1, pKey, type, idx);
    }
}

void glTFImporter::ImportMaterials(glTF::Asset& r) {
    mScene->mNumMaterials = unsigned(r.materials.Size());
    mScene->mMaterials = new aiMaterial*[mScene->mNumMaterials];

    for (unsigned int i = 0; i < mScene->mNumMaterials; ++i) {
        aiMaterial* aimat = mScene->mMaterials[i] = new aiMaterial();

        Material& mat = r.materials[i];

        /*if (!mat.name.empty())*/ {
            aiString str(mat.id /*mat.name*/);
            aimat->AddProperty(&str, AI_MATKEY_NAME);
        }

        SetMaterialColorProperty(embeddedTexIdxs, r, mat.ambient,  aimat, aiTextureType_AMBIENT,  AI_MATKEY_COLOR_AMBIENT );
        SetMaterialColorProperty(embeddedTexIdxs, r, mat.diffuse,  aimat, aiTextureType_DIFFUSE,  AI_MATKEY_COLOR_DIFFUSE );
        SetMaterialColorProperty(embeddedTexIdxs, r, mat.specular, aimat, aiTextureType_SPECULAR, AI_MATKEY_COLOR_SPECULAR);
        SetMaterialColorProperty(embeddedTexIdxs, r, mat.emission, aimat, aiTextureType_EMISSIVE, AI_MATKEY_COLOR_EMISSIVE);

        aimat->AddProperty(&mat.doubleSided, 1, AI_MATKEY_TWOSIDED);

        if (mat.transparent && (mat.transparency != 1.0f)) {
            aimat->AddProperty(&mat.transparency, 1, AI_MATKEY_OPACITY);
        }

        if (mat.shininess > 0.f) {
            aimat->AddProperty(&mat.shininess, 1, AI_MATKEY_SHININESS);
        }
    }

    if (mScene->mNumMaterials == 0) {
        mScene->mNumMaterials = 1;
        mScene->mMaterials = new aiMaterial*[1];
        mScene->mMaterials[0] = new aiMaterial();
    }
}


static inline void SetFace(aiFace& face, int a)
{
    face.mNumIndices = 1;
    face.mIndices = new unsigned int[1];
    face.mIndices[0] = a;
}

static inline void SetFace(aiFace& face, int a, int b)
{
    face.mNumIndices = 2;
    face.mIndices = new unsigned int[2];
    face.mIndices[0] = a;
    face.mIndices[1] = b;
}

static inline void SetFace(aiFace& face, int a, int b, int c)
{
    face.mNumIndices = 3;
    face.mIndices = new unsigned int[3];
    face.mIndices[0] = a;
    face.mIndices[1] = b;
    face.mIndices[2] = c;
}

#ifdef ASSIMP_BUILD_DEBUG
static inline bool CheckValidFacesIndices(aiFace* faces, unsigned nFaces, unsigned nVerts)
{
    for (unsigned i = 0; i < nFaces; ++i) {
        for (unsigned j = 0; j < faces[i].mNumIndices; ++j) {
            unsigned idx = faces[i].mIndices[j];
            if (idx >= nVerts)
                return false;
        }
    }
    return true;
}
#endif // ASSIMP_BUILD_DEBUG

void glTFImporter::ImportMeshes(glTF::Asset& r)
{
    std::vector<aiMesh*> meshes;

    unsigned int k = 0;

    for (unsigned int m = 0; m < r.meshes.Size(); ++m) {
        Mesh& mesh = r.meshes[m];

		// Check if mesh extensions is used
		if(mesh.Extension.size() > 0)
		{
			for(Mesh::SExtension* cur_ext : mesh.Extension)
			{
#ifdef ASSIMP_IMPORTER_GLTF_USE_OPEN3DGC
				if(cur_ext->Type == Mesh::SExtension::EType::Compression_Open3DGC)
				{
					// Limitations for meshes when using Open3DGC-compression.
					// It's a current limitation of sp... Specification have not this part still - about mesh compression. Why only one primitive?
					// Because glTF is very flexibly. But in fact it ugly flexible. Every primitive can has own set of accessors and accessors can
					// point to a-a-a-a-any part of buffer (through bufferview of course) and even to another buffer. We know that "Open3DGC-compression"
					// is applicable only to part of buffer. As we can't guaranty continuity of the data for decoder, we will limit quantity of primitives.
					// Yes indices, coordinates etc. still can br stored in different buffers, but with current specification it's a exporter problem.
					// Also primitive can has only one of "POSITION", "NORMAL" and less then "AI_MAX_NUMBER_OF_TEXTURECOORDS" of "TEXCOORD". All accessor
					// of primitive must point to one continuous region of the buffer.
					if(mesh.primitives.size() > 2) throw DeadlyImportError("GLTF: When using Open3DGC compression then only one primitive per mesh are allowed.");

					Mesh::SCompression_Open3DGC* o3dgc_ext = (Mesh::SCompression_Open3DGC*)cur_ext;
					Ref<Buffer> buf = r.buffers.Get(o3dgc_ext->Buffer);

					buf->EncodedRegion_SetCurrent(mesh.id);
				}
				else
#endif
				{
					throw DeadlyImportError("GLTF: Can not import mesh: unknown mesh extension (code: \"" + to_string(cur_ext->Type) +
											"\"), only Open3DGC is supported.");
				}
			}
		}// if(mesh.Extension.size() > 0)

		meshOffsets.push_back(k);
        k += unsigned(mesh.primitives.size());

        for (unsigned int p = 0; p < mesh.primitives.size(); ++p) {
            Mesh::Primitive& prim = mesh.primitives[p];

            aiMesh* aim = new aiMesh();
            meshes.push_back(aim);

            aim->mName = mesh.id;
            if (mesh.primitives.size() > 1) {
                ai_uint32& len = aim->mName.length;
                aim->mName.data[len] = '-';
                len += 1 + ASSIMP_itoa10(aim->mName.data + len + 1, unsigned(MAXLEN - len - 1), p);
            }

            switch (prim.mode) {
                case PrimitiveMode_POINTS:
                    aim->mPrimitiveTypes |= aiPrimitiveType_POINT;
                    break;

                case PrimitiveMode_LINES:
                case PrimitiveMode_LINE_LOOP:
                case PrimitiveMode_LINE_STRIP:
                    aim->mPrimitiveTypes |= aiPrimitiveType_LINE;
                    break;

                case PrimitiveMode_TRIANGLES:
                case PrimitiveMode_TRIANGLE_STRIP:
                case PrimitiveMode_TRIANGLE_FAN:
                    aim->mPrimitiveTypes |= aiPrimitiveType_TRIANGLE;
                    break;
            }

            Mesh::Primitive::Attributes& attr = prim.attributes;

			if (attr.position.size() > 0 && attr.position[0]) {
                aim->mNumVertices = attr.position[0]->count;
                attr.position[0]->ExtractData(aim->mVertices);
			}

			if (attr.normal.size() > 0 && attr.normal[0]) attr.normal[0]->ExtractData(aim->mNormals);

            for (size_t tc = 0; tc < attr.texcoord.size() && tc < AI_MAX_NUMBER_OF_TEXTURECOORDS; ++tc) {
                attr.texcoord[tc]->ExtractData(aim->mTextureCoords[tc]);
                aim->mNumUVComponents[tc] = attr.texcoord[tc]->GetNumComponents();

                aiVector3D* values = aim->mTextureCoords[tc];
                for (unsigned int i = 0; i < aim->mNumVertices; ++i) {
                    values[i].y = 1 - values[i].y; // Flip Y coords
                }
            }


            aiFace* faces = 0;
            unsigned int nFaces = 0;

            if (prim.indices) {
                unsigned int count = prim.indices->count;

                Accessor::Indexer data = prim.indices->GetIndexer();
                ai_assert(data.IsValid());

                switch (prim.mode) {
                    case PrimitiveMode_POINTS: {
                        nFaces = count;
                        faces = new aiFace[nFaces];
                        for (unsigned int i = 0; i < count; ++i) {
                            SetFace(faces[i], data.GetUInt(i));
                        }
                        break;
                    }

                    case PrimitiveMode_LINES: {
                        nFaces = count / 2;
                        faces = new aiFace[nFaces];
                        for (unsigned int i = 0; i < count; i += 2) {
                            SetFace(faces[i / 2], data.GetUInt(i), data.GetUInt(i + 1));
                        }
                        break;
                    }

                    case PrimitiveMode_LINE_LOOP:
                    case PrimitiveMode_LINE_STRIP: {
                        nFaces = count - ((prim.mode == PrimitiveMode_LINE_STRIP) ? 1 : 0);
                        faces = new aiFace[nFaces];
                        SetFace(faces[0], data.GetUInt(0), data.GetUInt(1));
                        for (unsigned int i = 2; i < count; ++i) {
                            SetFace(faces[i - 1], faces[i - 2].mIndices[1], data.GetUInt(i));
                        }
                        if (prim.mode == PrimitiveMode_LINE_LOOP) { // close the loop
                            SetFace(faces[count - 1], faces[count - 2].mIndices[1], faces[0].mIndices[0]);
                        }
                        break;
                    }

                    case PrimitiveMode_TRIANGLES: {
                        nFaces = count / 3;
                        faces = new aiFace[nFaces];
                        for (unsigned int i = 0; i < count; i += 3) {
                            SetFace(faces[i / 3], data.GetUInt(i), data.GetUInt(i + 1), data.GetUInt(i + 2));
                        }
                        break;
                    }
                    case PrimitiveMode_TRIANGLE_STRIP: {
                        nFaces = count - 2;
                        faces = new aiFace[nFaces];
                        SetFace(faces[0], data.GetUInt(0), data.GetUInt(1), data.GetUInt(2));
                        for (unsigned int i = 3; i < count; ++i) {
                            SetFace(faces[i - 2], faces[i - 1].mIndices[1], faces[i - 1].mIndices[2], data.GetUInt(i));
                        }
                        break;
                    }
                    case PrimitiveMode_TRIANGLE_FAN:
                        nFaces = count - 2;
                        faces = new aiFace[nFaces];
                        SetFace(faces[0], data.GetUInt(0), data.GetUInt(1), data.GetUInt(2));
                        for (unsigned int i = 3; i < count; ++i) {
                            SetFace(faces[i - 2], faces[0].mIndices[0], faces[i - 1].mIndices[2], data.GetUInt(i));
                        }
                        break;
                }
            }
            else { // no indices provided so directly generate from counts

                // use the already determined count as it includes checks 
                unsigned int count = aim->mNumVertices;

                switch (prim.mode) {
                case PrimitiveMode_POINTS: {
                    nFaces = count;
                    faces = new aiFace[nFaces];
                    for (unsigned int i = 0; i < count; ++i) {
                        SetFace(faces[i], i);
                    }
                    break;
                }

                case PrimitiveMode_LINES: {
                    nFaces = count / 2;
                    faces = new aiFace[nFaces];
                    for (unsigned int i = 0; i < count; i += 2) {
                        SetFace(faces[i / 2], i, i + 1);
                    }
                    break;
                }

                case PrimitiveMode_LINE_LOOP:
                case PrimitiveMode_LINE_STRIP: {
                    nFaces = count - ((prim.mode == PrimitiveMode_LINE_STRIP) ? 1 : 0);
                    faces = new aiFace[nFaces];
                    SetFace(faces[0], 0, 1);
                    for (unsigned int i = 2; i < count; ++i) {
                        SetFace(faces[i - 1], faces[i - 2].mIndices[1], i);
                    }
                    if (prim.mode == PrimitiveMode_LINE_LOOP) { // close the loop
                        SetFace(faces[count - 1], faces[count - 2].mIndices[1], faces[0].mIndices[0]);
                    }
                    break;
                }

                case PrimitiveMode_TRIANGLES: {
                    nFaces = count / 3;
                    faces = new aiFace[nFaces];
                    for (unsigned int i = 0; i < count; i += 3) {
                        SetFace(faces[i / 3], i, i + 1, i + 2);
                    }
                    break;
                }
                case PrimitiveMode_TRIANGLE_STRIP: {
                    nFaces = count - 2;
                    faces = new aiFace[nFaces];
                    SetFace(faces[0], 0, 1, 2);
                    for (unsigned int i = 3; i < count; ++i) {
                        SetFace(faces[i - 2], faces[i - 1].mIndices[1], faces[i - 1].mIndices[2], i);
                    }
                    break;
                }
                case PrimitiveMode_TRIANGLE_FAN:
                    nFaces = count - 2;
                    faces = new aiFace[nFaces];
                    SetFace(faces[0], 0, 1, 2);
                    for (unsigned int i = 3; i < count; ++i) {
                        SetFace(faces[i - 2], faces[0].mIndices[0], faces[i - 1].mIndices[2], i);
                    }
                    break;
                }
            }

            if (faces) {
                aim->mFaces = faces;
                aim->mNumFaces = nFaces;
                ai_assert(CheckValidFacesIndices(faces, nFaces, aim->mNumVertices));
            }

            if (prim.material) {
                aim->mMaterialIndex = prim.material.GetIndex();
            }
        }
    }

    meshOffsets.push_back(k);

    CopyVector(meshes, mScene->mMeshes, mScene->mNumMeshes);
}

void glTFImporter::ImportCameras(glTF::Asset& r) {
    if (!r.cameras.Size()) {
        return;
    }

    mScene->mNumCameras = r.cameras.Size();
    mScene->mCameras = new aiCamera*[r.cameras.Size()];
    for (size_t i = 0; i < r.cameras.Size(); ++i) {
        Camera& cam = r.cameras[i];

        aiCamera* aicam = mScene->mCameras[i] = new aiCamera();

        if (cam.type == Camera::Perspective) {
            aicam->mAspect        = cam.perspective.aspectRatio;
            aicam->mHorizontalFOV = cam.perspective.yfov * ((aicam->mAspect == 0.f) ? 1.f : aicam->mAspect);
            aicam->mClipPlaneFar  = cam.perspective.zfar;
            aicam->mClipPlaneNear = cam.perspective.znear;
        } else {
            aicam->mClipPlaneFar = cam.ortographic.zfar;
            aicam->mClipPlaneNear = cam.ortographic.znear;
            aicam->mHorizontalFOV = 0.0;
            aicam->mAspect = 1.0f;
            if (0.f != cam.ortographic.ymag) {
                aicam->mAspect = cam.ortographic.xmag / cam.ortographic.ymag;
            }
        }
    }
}

void glTFImporter::ImportLights(glTF::Asset& r)
{
    if (!r.lights.Size()) return;

    mScene->mNumLights = r.lights.Size();
    mScene->mLights = new aiLight*[r.lights.Size()];

    for (size_t i = 0; i < r.lights.Size(); ++i) {
        Light& l = r.lights[i];

        aiLight* ail = mScene->mLights[i] = new aiLight();

        switch (l.type) {
            case Light::Type_directional:
                ail->mType = aiLightSource_DIRECTIONAL; break;

            case Light::Type_spot:
                ail->mType = aiLightSource_SPOT; break;

            case Light::Type_ambient:
                ail->mType = aiLightSource_AMBIENT; break;

            default: // Light::Type_point
                ail->mType = aiLightSource_POINT; break;
        }

        CopyValue(l.color, ail->mColorAmbient);
        CopyValue(l.color, ail->mColorDiffuse);
        CopyValue(l.color, ail->mColorSpecular);

        ail->mAngleOuterCone = l.falloffAngle;
        ail->mAngleInnerCone = l.falloffExponent; // TODO fix this, it does not look right at all

        ail->mAttenuationConstant  = l.constantAttenuation;
        ail->mAttenuationLinear    = l.linearAttenuation;
        ail->mAttenuationQuadratic = l.quadraticAttenuation;
    }
}


aiNode* ImportNode(aiScene* pScene, glTF::Asset& r, std::vector<unsigned int>& meshOffsets, glTF::Ref<glTF::Node>& ptr)
{
    Node& node = *ptr;

    aiNode* ainode = new aiNode(node.id);

    if (!node.children.empty()) {
        ainode->mNumChildren = unsigned(node.children.size());
        ainode->mChildren = new aiNode*[ainode->mNumChildren];

        for (unsigned int i = 0; i < ainode->mNumChildren; ++i) {
            aiNode* child = ImportNode(pScene, r, meshOffsets, node.children[i]);
            child->mParent = ainode;
            ainode->mChildren[i] = child;
        }
    }

    aiMatrix4x4& matrix = ainode->mTransformation;
    if (node.matrix.isPresent) {
        CopyValue(node.matrix.value, matrix);
    }
    else {
        if (node.translation.isPresent) {
            aiVector3D trans;
            CopyValue(node.translation.value, trans);
            aiMatrix4x4 t;
            aiMatrix4x4::Translation(trans, t);
            matrix = t * matrix;
        }

        if (node.scale.isPresent) {
            aiVector3D scal(1.f);
            CopyValue(node.scale.value, scal);
            aiMatrix4x4 s;
            aiMatrix4x4::Scaling(scal, s);
            matrix = s * matrix;
        }


        if (node.rotation.isPresent) {
            aiQuaternion rot;
            CopyValue(node.rotation.value, rot);
            matrix = aiMatrix4x4(rot.GetMatrix()) * matrix;
        }
    }

    if (!node.meshes.empty()) {
        int count = 0;
        for (size_t i = 0; i < node.meshes.size(); ++i) {
            int idx = node.meshes[i].GetIndex();
            count += meshOffsets[idx + 1] - meshOffsets[idx];
        }

        ainode->mNumMeshes = count;
        ainode->mMeshes = new unsigned int[count];

        int k = 0;
        for (size_t i = 0; i < node.meshes.size(); ++i) {
            int idx = node.meshes[i].GetIndex();
            for (unsigned int j = meshOffsets[idx]; j < meshOffsets[idx + 1]; ++j, ++k) {
                ainode->mMeshes[k] = j;
            }
        }
    }

    if (node.camera) {
        pScene->mCameras[node.camera.GetIndex()]->mName = ainode->mName;
    }

    if (node.light) {
        pScene->mLights[node.light.GetIndex()]->mName = ainode->mName;
    }

    return ainode;
}

void glTFImporter::ImportNodes(glTF::Asset& r)
{
    if (!r.scene) return;

    std::vector< Ref<Node> > rootNodes = r.scene->nodes;

    // The root nodes
    unsigned int numRootNodes = unsigned(rootNodes.size());
    if (numRootNodes == 1) { // a single root node: use it
        mScene->mRootNode = ImportNode(mScene, r, meshOffsets, rootNodes[0]);
    }
    else if (numRootNodes > 1) { // more than one root node: create a fake root
        aiNode* root = new aiNode("ROOT");
        root->mChildren = new aiNode*[numRootNodes];
        for (unsigned int i = 0; i < numRootNodes; ++i) {
            aiNode* node = ImportNode(mScene, r, meshOffsets, rootNodes[i]);
            node->mParent = root;
            root->mChildren[root->mNumChildren++] = node;
        }
        mScene->mRootNode = root;
    }

    //if (!mScene->mRootNode) {
    //  mScene->mRootNode = new aiNode("EMPTY");
    //}
}

void glTFImporter::ImportEmbeddedTextures(glTF::Asset& r)
{
    embeddedTexIdxs.resize(r.images.Size(), -1);

    int numEmbeddedTexs = 0;
    for (size_t i = 0; i < r.images.Size(); ++i) {
        if (r.images[i].HasData())
            numEmbeddedTexs += 1;
    }

    if (numEmbeddedTexs == 0)
        return;

    mScene->mTextures = new aiTexture*[numEmbeddedTexs];

    // Add the embedded textures
    for (size_t i = 0; i < r.images.Size(); ++i) {
        Image &img = r.images[i];
        if (!img.HasData()) continue;

        int idx = mScene->mNumTextures++;
        embeddedTexIdxs[i] = idx;

        aiTexture* tex = mScene->mTextures[idx] = new aiTexture();

        size_t length = img.GetDataLength();
        void* data = img.StealData();

        tex->mWidth = static_cast<unsigned int>(length);
        tex->mHeight = 0;
        tex->pcData = reinterpret_cast<aiTexel*>(data);

        if (!img.mimeType.empty()) {
            const char* ext = strchr(img.mimeType.c_str(), '/') + 1;
            if (ext) {
                if (strcmp(ext, "jpeg") == 0) ext = "jpg";

                size_t len = strlen(ext);
                if (len <= 3) {
                    strcpy(tex->achFormatHint, ext);
                }
            }
        }
    }
}

void glTFImporter::InternReadFile(const std::string& pFile, aiScene* pScene, IOSystem* pIOHandler)
{
    // clean all member arrays
    meshOffsets.clear();
    embeddedTexIdxs.clear();

    this->mScene = pScene;

    // read the asset file
    glTF::Asset asset(pIOHandler);
    asset.Load(pFile, GetExtension(pFile) == "glb");


    //
    // Copy the data out
    //

    ImportEmbeddedTextures(asset);
    ImportMaterials(asset);

    ImportMeshes(asset);

    ImportCameras(asset);
    ImportLights(asset);

    ImportNodes(asset);


    if (pScene->mNumMeshes == 0) {
        pScene->mFlags |= AI_SCENE_FLAGS_INCOMPLETE;
    }
}

#endif // ASSIMP_BUILD_NO_GLTF_IMPORTER