obj materials: Added ior

Author: ft-lab

tests/data/assets/box_with_texture.mtl

@@ -1,7 +1,7 @@
 newmtl texture_mat
 Ns 250.000000
 Ka 1.000000 1.000000 1.000000
-Ks 0.500000 0.500000 0.500000
+Ks 0.000000 0.000000 0.000000
 Ke 0.000000 0.000000 0.000000
 Ni 1.450000
 d 1.000000

tests/data/assets/box_with_texture_opacity.mtl

@@ -3,7 +3,7 @@ Ns 250.000000
 Ka 1.000000 1.000000 1.000000
 Ks 0.000000 0.000000 0.000000
 Ke 0.000000 0.000000 0.000000
-Ni 1.450000
+Ni 1.000000
 d 1.000000
 illum 2
 map_Kd ./grid.png

tests/testMaterial.py

@@ -456,6 +456,8 @@ def test_material_mesh_texture(self):
         self.assertIsNone(diffuse_color)
         opacity = self.get_material_opacity(texture_material)
         self.assertAlmostEqual(opacity, 1.0, places=6)
+        ior = self.get_material_ior(texture_material)
+        self.assertAlmostEqual(ior, 1.45, places=6)
         diffuse_color_texture_path = self.get_material_texture_path(texture_material, "diffuseColor")
         self.assertEqual(diffuse_color_texture_path, pathlib.Path("./Textures/grid.png"))
         normal_texture_path = self.get_material_texture_path(texture_material, "normal")
@@ -473,6 +475,8 @@ def test_material_mesh_texture(self):
 
         diffuse_color = self.get_material_diffuse_color(texture_opacity_material)
         self.assertIsNone(diffuse_color)
+        ior = self.get_material_ior(texture_opacity_material)
+        self.assertAlmostEqual(ior, 1.0, places=6)
         opacity_texture_path = self.get_material_texture_path(texture_opacity_material, "opacity")
         self.assertEqual(opacity_texture_path, pathlib.Path("./Textures/opacity.png"))
 
@@ -482,6 +486,8 @@ def test_material_mesh_texture(self):
         texture_specular_workflow_material = UsdShade.Material(texture_specular_workflow_material_prim)
         self.assertTrue(texture_specular_workflow_material)
 
+        ior = self.get_material_ior(texture_specular_workflow_material)
+        self.assertAlmostEqual(ior, 1.45, places=6)
         diffuse_color = self.get_material_diffuse_color(texture_specular_workflow_material)
         diffuse_color = usdex.core.linearToSrgb(diffuse_color)
         self.assertTrue(Gf.IsClose(diffuse_color, Gf.Vec3f(0.4, 0.4, 0.4), 1e-6))

tests/util/ConverterTestCase.py

@@ -49,6 +49,10 @@ def get_material_metallic(self, material: UsdShade.Material) -> float:
         shader: UsdShade.Shader = usdex.core.computeEffectivePreviewSurfaceShader(material)
         return shader.GetInput("metallic").Get()
 
+    def get_material_ior(self, material: UsdShade.Material) -> float:
+        shader: UsdShade.Shader = usdex.core.computeEffectivePreviewSurfaceShader(material)
+        return shader.GetInput("ior").Get()
+
     def get_material_texture_path(self, material: UsdShade.Material, texture_type: str = "diffuseColor") -> pathlib.Path:
         """
         Get the texture path for the given texture type.

urdf_usd_converter/_impl/material.py

@@ -48,6 +48,7 @@ def convert_materials(data: ConversionData):
             material_data.opacity,
             material_data.roughness,
             material_data.metallic,
+            material_data.ior,
             material_data.diffuse_texture_path,
             material_data.specular_texture_path,
             material_data.normal_texture_path,
@@ -102,6 +103,7 @@ def _convert_material(
     opacity: float,
     roughness: float,
     metallic: float,
+    ior: float,
     diffuse_texture_path: pathlib.Path | None,
     specular_texture_path: pathlib.Path | None,
     normal_texture_path: pathlib.Path | None,
@@ -123,6 +125,7 @@ def _convert_material(
         opacity: The opacity of the material.
         roughness: The roughness of the material.
         metallic: The metallic of the material.
+        ior: The ior of the material.
         diffuse_texture_path: The path to the diffuse texture.
         specular_texture_path: The path to the specular texture.
         normal_texture_path: The path to the normal texture.
@@ -151,6 +154,10 @@ def _convert_material(
     if not material_prim:
         Tf.RaiseRuntimeError(f'Failed to convert material "{safe_name}"')
 
+    surface_shader: UsdShade.Shader = usdex.core.computeEffectivePreviewSurfaceShader(material_prim)
+    if ior != 0.0:
+        surface_shader.CreateInput("ior", Sdf.ValueTypeNames.Float).Set(ior)
+
     if diffuse_texture_path:
         usdex.core.addDiffuseTextureToPreviewMaterial(material_prim, _get_texture_asset_path(diffuse_texture_path, texture_paths, data))
 
@@ -168,9 +175,8 @@ def _convert_material(
 
     # If the specular color is not black or the specular texture exists, use the specular workflow.
     if specular_color != [0, 0, 0] or specular_texture_path:
-        shader: UsdShade.Shader = usdex.core.computeEffectivePreviewSurfaceShader(material_prim)
-        shader.CreateInput("useSpecularWorkflow", Sdf.ValueTypeNames.Int).Set(1)
-        shader.CreateInput("specularColor", Sdf.ValueTypeNames.Color3f).Set(specular_color)
+        surface_shader.CreateInput("useSpecularWorkflow", Sdf.ValueTypeNames.Int).Set(1)
+        surface_shader.CreateInput("specularColor", Sdf.ValueTypeNames.Color3f).Set(specular_color)
         if specular_texture_path:
             _add_specular_texture_to_preview_material(material_prim, _get_texture_asset_path(specular_texture_path, texture_paths, data))
 
@@ -284,6 +290,7 @@ def store_obj_material_data(mesh_file_path: pathlib.Path, reader: tinyobjloader.
         material_data.diffuse_color = Gf.Vec3f(material.diffuse[0], material.diffuse[1], material.diffuse[2])
         material_data.specular_color = Gf.Vec3f(material.specular[0], material.specular[1], material.specular[2])
         material_data.opacity = material.dissolve
+        material_data.ior = material.ior if material.ior else 0.0
 
         # The following is the extended specification of obj.
         material_data.roughness = material.roughness if material.roughness else 0.5

urdf_usd_converter/_impl/material_data.py

@@ -29,6 +29,7 @@ def __init__(self):
         self.opacity: float = 1.0
         self.roughness: float = 0.5
         self.metallic: float = 0.0
+        self.ior: float = 0.0
 
         self.diffuse_texture_path: pathlib.Path | None = None
         self.specular_texture_path: pathlib.Path | None = None