Implemented basic texture mapping for PBR material definitions

This reads materials properly from Maya and expands on existing functionality to make this work properly.

aiTextureType_SHININESS no longer used as not appropriate for PBR texture as it is legacy.

This fix will be also present in assimp soon.

5 files changed, 119 insertions, 34 deletions

diff --git a/modules/assimp/editor_scene_importer_assimp.cpp b/modules/assimp/editor_scene_importer_assimp.cpp
index e5439fd132..fee2001a07 100644
--- a/modules/assimp/editor_scene_importer_assimp.cpp
+++ b/modules/assimp/editor_scene_importer_assimp.cpp
@@ -680,6 +680,26 @@ Ref<Mesh> EditorSceneImporterAssimp::_generate_mesh_from_surface_indices(
 		mat->set_cull_mode(SpatialMaterial::CULL_BACK);
 
 		// Now process materials
+		aiTextureType base_color = aiTextureType_BASE_COLOR;
+		{
+			String filename, path;
+			AssimpImageData image_data;
+
+			if (AssimpUtils::GetAssimpTexture(state, ai_material, base_color, filename, path, image_data)) {
+				AssimpUtils::set_texture_mapping_mode(image_data.map_mode, image_data.texture);
+
+				// anything transparent must be culled
+				if (image_data.raw_image->detect_alpha() != Image::ALPHA_NONE) {
+					mat->set_feature(SpatialMaterial::FEATURE_TRANSPARENT, true);
+					mat->set_depth_draw_mode(SpatialMaterial::DepthDrawMode::DEPTH_DRAW_ALPHA_OPAQUE_PREPASS);
+					mat->set_cull_mode(SpatialMaterial::CULL_DISABLED); // since you can see both sides in transparent mode
+				}
+
+				mat->set_texture(SpatialMaterial::TEXTURE_ALBEDO, image_data.texture);
+			}
+		}
+
+		// Now process materials
 		aiTextureType tex_diffuse = aiTextureType_DIFFUSE;
 		{
 			String filename, path;
@@ -731,6 +751,60 @@ Ref<Mesh> EditorSceneImporterAssimp::_generate_mesh_from_surface_indices(
 			}
 		}
 
+		aiTextureType tex_normal_camera = aiTextureType_NORMAL_CAMERA;
+		{
+			String filename, path;
+			Ref<ImageTexture> texture;
+			AssimpImageData image_data;
+
+			// Process texture normal map
+			if (AssimpUtils::GetAssimpTexture(state, ai_material, tex_normal_camera, filename, path, image_data)) {
+				AssimpUtils::set_texture_mapping_mode(image_data.map_mode, image_data.texture);
+				mat->set_feature(SpatialMaterial::Feature::FEATURE_NORMAL_MAPPING, true);
+				mat->set_texture(SpatialMaterial::TEXTURE_NORMAL, image_data.texture);
+			}
+		}
+
+		aiTextureType tex_emission_color = aiTextureType_EMISSION_COLOR;
+		{
+			String filename, path;
+			Ref<ImageTexture> texture;
+			AssimpImageData image_data;
+
+			// Process texture normal map
+			if (AssimpUtils::GetAssimpTexture(state, ai_material, tex_emission_color, filename, path, image_data)) {
+				AssimpUtils::set_texture_mapping_mode(image_data.map_mode, image_data.texture);
+				mat->set_feature(SpatialMaterial::Feature::FEATURE_NORMAL_MAPPING, true);
+				mat->set_texture(SpatialMaterial::TEXTURE_NORMAL, image_data.texture);
+			}
+		}
+
+		aiTextureType tex_metalness = aiTextureType_METALNESS;
+		{
+			String filename, path;
+			Ref<ImageTexture> texture;
+			AssimpImageData image_data;
+
+			// Process texture normal map
+			if (AssimpUtils::GetAssimpTexture(state, ai_material, tex_metalness, filename, path, image_data)) {
+				AssimpUtils::set_texture_mapping_mode(image_data.map_mode, image_data.texture);
+				mat->set_texture(SpatialMaterial::TEXTURE_METALLIC, image_data.texture);
+			}
+		}
+
+		aiTextureType tex_roughness = aiTextureType_DIFFUSE_ROUGHNESS;
+		{
+			String filename, path;
+			Ref<ImageTexture> texture;
+			AssimpImageData image_data;
+
+			// Process texture normal map
+			if (AssimpUtils::GetAssimpTexture(state, ai_material, tex_roughness, filename, path, image_data)) {
+				AssimpUtils::set_texture_mapping_mode(image_data.map_mode, image_data.texture);
+				mat->set_texture(SpatialMaterial::TEXTURE_ROUGHNESS, image_data.texture);
+			}
+		}
+
 		aiTextureType tex_emissive = aiTextureType_EMISSIVE;
 		{
 			String filename = "";
@@ -772,19 +846,6 @@ Ref<Mesh> EditorSceneImporterAssimp::_generate_mesh_from_surface_indices(
 			}
 		}
 
-		aiTextureType tex_roughness = aiTextureType_SHININESS;
-		{
-			String filename, path;
-			Ref<ImageTexture> texture;
-			AssimpImageData image_data;
-
-			// Process texture normal map
-			if (AssimpUtils::GetAssimpTexture(state, ai_material, tex_roughness, filename, path, image_data)) {
-				AssimpUtils::set_texture_mapping_mode(image_data.map_mode, image_data.texture);
-				mat->set_texture(SpatialMaterial::TEXTURE_ROUGHNESS, image_data.texture);
-			}
-		}
-
 		Array array_mesh = st->commit_to_arrays();
 		Array morphs;
 		morphs.resize(ai_mesh->mNumAnimMeshes);
diff --git a/thirdparty/assimp/code/FBX/FBXConverter.cpp b/thirdparty/assimp/code/FBX/FBXConverter.cpp
index 9bd970098e..69e57f73ea 100644
--- a/thirdparty/assimp/code/FBX/FBXConverter.cpp
+++ b/thirdparty/assimp/code/FBX/FBXConverter.cpp
@@ -78,7 +78,7 @@ namespace Assimp {
 
 #define CONVERT_FBX_TIME(time) static_cast<double>(time) / 46186158000L
 
-        FBXConverter::FBXConverter(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit )
+        FBXConverter::FBXConverter(aiScene* out, const Document& doc, bool removeEmptyBones )
         : defaultMaterialIndex()
         , lights()
         , cameras()
@@ -90,8 +90,7 @@ namespace Assimp {
         , mNodeNames()
         , anim_fps()
         , out(out)
-        , doc(doc)
-        , mCurrentUnit(FbxUnit::cm) {
+        , doc(doc) {
             // animations need to be converted first since this will
             // populate the node_anim_chain_bits map, which is needed
             // to determine which nodes need to be generated.
@@ -2002,6 +2001,12 @@ namespace Assimp {
             TrySetTextureProperties(out_mat, textures, "Maya|SpecularTexture", aiTextureType_SPECULAR, mesh);
             TrySetTextureProperties(out_mat, textures, "Maya|FalloffTexture", aiTextureType_OPACITY, mesh);
             TrySetTextureProperties(out_mat, textures, "Maya|ReflectionMapTexture", aiTextureType_REFLECTION, mesh);
+            // Maya PBR
+            TrySetTextureProperties(out_mat, textures, "Maya|baseColor|file", aiTextureType_BASE_COLOR, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|normalCamera|file", aiTextureType_NORMAL_CAMERA, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|emissionColor|file", aiTextureType_EMISSION_COLOR, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|metalness|file", aiTextureType_METALNESS, mesh);
+            TrySetTextureProperties(out_mat, textures, "Maya|diffuseRoughness|file", aiTextureType_DIFFUSE_ROUGHNESS, mesh);
         }
 
         void FBXConverter::SetTextureProperties(aiMaterial* out_mat, const LayeredTextureMap& layeredTextures, const MeshGeometry* const mesh)
@@ -3589,9 +3594,9 @@ void FBXConverter::SetShadingPropertiesRaw(aiMaterial* out_mat, const PropertyTa
         }
 
         // ------------------------------------------------------------------------------------------------
-        void ConvertToAssimpScene(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit)
+        void ConvertToAssimpScene(aiScene* out, const Document& doc, bool removeEmptyBones)
         {
-            FBXConverter converter(out, doc, removeEmptyBones, unit);
+            FBXConverter converter(out, doc, removeEmptyBones);
         }
 
     } // !FBX
diff --git a/thirdparty/assimp/code/FBX/FBXConverter.h b/thirdparty/assimp/code/FBX/FBXConverter.h
index b458627392..ab610058a4 100644
--- a/thirdparty/assimp/code/FBX/FBXConverter.h
+++ b/thirdparty/assimp/code/FBX/FBXConverter.h
@@ -92,7 +92,7 @@ enum class FbxUnit {
  *  @param doc Parsed FBX document
  *  @param removeEmptyBones Will remove bones, which do not have any references to vertices.
  */
-void ConvertToAssimpScene(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit);
+void ConvertToAssimpScene(aiScene* out, const Document& doc, bool removeEmptyBones);
 
 /** Dummy class to encapsulate the conversion process */
 class FBXConverter {
@@ -123,7 +123,7 @@ public:
     };
 
 public:
-    FBXConverter(aiScene* out, const Document& doc, bool removeEmptyBones, FbxUnit unit);
+    FBXConverter(aiScene* out, const Document& doc, bool removeEmptyBones);
     ~FBXConverter();
 
 private:
diff --git a/thirdparty/assimp/code/FBX/FBXImporter.cpp b/thirdparty/assimp/code/FBX/FBXImporter.cpp
index bd359dbf29..271935a568 100644
--- a/thirdparty/assimp/code/FBX/FBXImporter.cpp
+++ b/thirdparty/assimp/code/FBX/FBXImporter.cpp
@@ -191,7 +191,7 @@ void FBXImporter::InternReadFile( const std::string& pFile, aiScene* pScene, IOS
         }
 
         // convert the FBX DOM to aiScene
-        ConvertToAssimpScene(pScene, doc, settings.removeEmptyBones, unit);
+        ConvertToAssimpScene(pScene, doc, settings.removeEmptyBones);
 
         // size relative to cm
         float size_relative_to_cm = doc.GlobalSettings().UnitScaleFactor();
diff --git a/thirdparty/assimp/include/assimp/material.h b/thirdparty/assimp/include/assimp/material.h
index 4b5a1293dd..7ac643ced3 100644
--- a/thirdparty/assimp/include/assimp/material.h
+++ b/thirdparty/assimp/include/assimp/material.h
@@ -196,34 +196,40 @@ enum aiTextureType
      *  (#aiMaterialProperty::mSemantic) for all material properties
      *  *not* related to textures.
      */
-    aiTextureType_NONE = 0x0,
+    aiTextureType_NONE = 0,
+
+    /** LEGACY API MATERIALS 
+     * Legacy refers to materials which 
+     * Were originally implemented in the specifications around 2000.
+     * These must never be removed, as most engines support them.
+     */
 
     /** The texture is combined with the result of the diffuse
      *  lighting equation.
      */
-    aiTextureType_DIFFUSE = 0x1,
+    aiTextureType_DIFFUSE = 1,
 
     /** The texture is combined with the result of the specular
      *  lighting equation.
      */
-    aiTextureType_SPECULAR = 0x2,
+    aiTextureType_SPECULAR = 2,
 
     /** The texture is combined with the result of the ambient
      *  lighting equation.
      */
-    aiTextureType_AMBIENT = 0x3,
+    aiTextureType_AMBIENT = 3,
 
     /** The texture is added to the result of the lighting
      *  calculation. It isn't influenced by incoming light.
      */
-    aiTextureType_EMISSIVE = 0x4,
+    aiTextureType_EMISSIVE = 4,
 
     /** The texture is a height map.
      *
      *  By convention, higher gray-scale values stand for
      *  higher elevations from the base height.
      */
-    aiTextureType_HEIGHT = 0x5,
+    aiTextureType_HEIGHT = 5,
 
     /** The texture is a (tangent space) normal-map.
      *
@@ -231,7 +237,7 @@ enum aiTextureType
      *  normal maps. Assimp does (intentionally) not
      *  distinguish here.
      */
-    aiTextureType_NORMALS = 0x6,
+    aiTextureType_NORMALS = 6,
 
     /** The texture defines the glossiness of the material.
      *
@@ -240,21 +246,21 @@ enum aiTextureType
      *  function defined to map the linear color values in the
      *  texture to a suitable exponent. Have fun.
     */
-    aiTextureType_SHININESS = 0x7,
+    aiTextureType_SHININESS = 7,
 
     /** The texture defines per-pixel opacity.
      *
      *  Usually 'white' means opaque and 'black' means
      *  'transparency'. Or quite the opposite. Have fun.
     */
-    aiTextureType_OPACITY = 0x8,
+    aiTextureType_OPACITY = 8,
 
     /** Displacement texture
      *
      *  The exact purpose and format is application-dependent.
      *  Higher color values stand for higher vertex displacements.
     */
-    aiTextureType_DISPLACEMENT = 0x9,
+    aiTextureType_DISPLACEMENT = 9,
 
     /** Lightmap texture (aka Ambient Occlusion)
      *
@@ -263,14 +269,27 @@ enum aiTextureType
      *  scaling value for the final color value of a pixel. Its
      *  intensity is not affected by incoming light.
     */
-    aiTextureType_LIGHTMAP = 0xA,
+    aiTextureType_LIGHTMAP = 10,
 
     /** Reflection texture
      *
      * Contains the color of a perfect mirror reflection.
      * Rarely used, almost never for real-time applications.
     */
-    aiTextureType_REFLECTION = 0xB,
+    aiTextureType_REFLECTION = 11,
+
+    /** PBR Materials
+     * PBR definitions from maya and other modelling packages now use this standard.
+     * This was originally introduced around 2012.
+     * Support for this is in game engines like Godot, Unreal or Unity3D.
+     * Modelling packages which use this are very common now.
+     */
+
+    aiTextureType_BASE_COLOR = 12,
+    aiTextureType_NORMAL_CAMERA = 13,
+    aiTextureType_EMISSION_COLOR = 14,
+    aiTextureType_METALNESS = 15,
+    aiTextureType_DIFFUSE_ROUGHNESS = 16,
 
     /** Unknown texture
      *
@@ -278,7 +297,7 @@ enum aiTextureType
      *  above is considered to be 'unknown'. It is still imported,
      *  but is excluded from any further post-processing.
     */
-    aiTextureType_UNKNOWN = 0xC,
+    aiTextureType_UNKNOWN = 17,
 
 
 #ifndef SWIG