Assimp FBX Import support

Issues fixed:
- Updated assimp to latest and backported fixes into godot.
- Fixed file scale being ignored from FBX file.
- Fixed bone removal
- Implemented proper armature binding
- Fixed recursion not always going through the entire path
- Implemented assimp global scaling system
- Fixed assimp global scale process to support unit conversion
- Implemented proper fbx scaling
- Fixed asserts caused by missing faces in some models which could crash
- Fixed valid bone removal
- Fixed root node being overwriten by assimp which caused data loss
- Fixed armature construction so that it works with multiple roots
- Implemented basic support for FBX standard materials
- Refactoring to improve code quality and improve function reuse.
- Simplified node creation from assimp scene into subsections: create_light, create_mesh, create_bone.
- Creating meshes is now done after hierarchy is created so that the skeleton is always available.
- Added support to assimp to support file scale in all formats which call SetFileScale.
- Many other fixes provided into assimp.

Known issues:
- FBX pivots from Maya do not currently work. (workaround: for now use blender import and export to remove pivot tracks)
- Hierarchy creates an extra node for each mesh - this was done intentionally but we intended to do a pass to remove these as they're a required node.
- When an animated mesh has not executed any animation the rest pose is wrong.

Co-authored-by: K. S. Ernest (iFire) Lee <ernest.lee@chibifire.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/thirdparty/assimp/code/FBX/FBXImporter.cpp b/thirdparty/assimp/code/FBX/FBXImporter.cpp
index ec8bbd2b47..bd359dbf29 100644
--- a/thirdparty/assimp/code/FBX/FBXImporter.cpp
+++ b/thirdparty/assimp/code/FBX/FBXImporter.cpp
@@ -189,8 +189,16 @@ void FBXImporter::InternReadFile( const std::string& pFile, aiScene* pScene, IOS
         if (settings.convertToMeters) {
             unit = FbxUnit::m;
         }
+
         // convert the FBX DOM to aiScene
-        ConvertToAssimpScene(pScene,doc, settings.removeEmptyBones, unit);
+        ConvertToAssimpScene(pScene, doc, settings.removeEmptyBones, unit);
+
+        // size relative to cm
+        float size_relative_to_cm = doc.GlobalSettings().UnitScaleFactor();
+
+        // Set FBX file scale is relative to CM must be converted to M for
+        // assimp universal format (M)
+        SetFileScale( size_relative_to_cm * 0.01f);
 
         std::for_each(tokens.begin(),tokens.end(),Util::delete_fun<Token>());
     }