add aiProcess_GenNormals + aiProcess_GenSmoothNormals

pandatool/src/assimp/assimpLoader.cxx

@@ -129,6 +129,16 @@ read(const Filename &filename) {
   if (assimp_flip_winding_order) {
     flags |= aiProcess_FlipWindingOrder;
   }
+  if (assimp_gen_normals) {
+    if (assimp_smooth_normal_angle == 0.0) {
+      flags |= aiProcess_GenNormals;
+    }
+    else {
+      flags |= aiProcess_GenSmoothNormals;
+      _importer.SetPropertyFloat(AI_CONFIG_PP_GSN_MAX_SMOOTHING_ANGLE,
+        assimp_smooth_normal_angle);
+    }
+  }
 
   _scene = _importer.ReadFile(_filename.c_str(), flags);
   if (_scene == nullptr) {

pandatool/src/assimp/config_assimp.cxx

@@ -69,6 +69,23 @@ ConfigVariableBool assimp_flip_winding_order
           "the Assimp loader.  Note that you may need to clear the model-cache "
           "after changing this."));
 
+ConfigVariableBool assimp_gen_normals
+("assimp-gen-normals", false,
+ PRC_DESC("Set this true to generate normals (if absent from file) on import. "
+          "See assimp-smooth-normal-angle for more information. "
+          "Note that you may need to clear the model-cache after "
+          "changing this."));
+
+ConfigVariableDouble assimp_smooth_normal_angle
+("assimp-smooth-normal-angle", 0.0,
+ PRC_DESC("Set this to anything other than 0.0 in degrees (so 180.0 is PI) to "
+          "specify the maximum angle that may be between two face normals at "
+          "the same vertex position that are smoothed together. Sometimes "
+          "referred to as 'crease angle'. Only has effect if "
+          "assimp-gen-normals is set to true and the file does not contain "
+          "normals. Note that you may need to clear the model-cache after "
+          "changing this."));
+
 /**
  * Initializes the library.  This must be called at least once before any of
  * the functions or classes in this library can be used.  Normally it will be

pandatool/src/assimp/config_assimp.h

@@ -16,6 +16,7 @@
 
 #include "pandatoolbase.h"
 #include "configVariableBool.h"
+#include "configVariableDouble.h"
 #include "dconfig.h"
 
 ConfigureDecl(config_assimp, EXPCL_ASSIMP, EXPTP_ASSIMP);
@@ -29,6 +30,8 @@ extern ConfigVariableBool assimp_fix_infacing_normals;
 extern ConfigVariableBool assimp_optimize_meshes;
 extern ConfigVariableBool assimp_optimize_graph;
 extern ConfigVariableBool assimp_flip_winding_order;
+extern ConfigVariableBool assimp_gen_normals;
+extern ConfigVariableDouble assimp_smooth_normal_angle;
 
 extern EXPCL_ASSIMP void init_libassimp();