Updated exportStepMeta to handle materials

Author: adrianschneider94

cadquery/occ_impl/assembly.py

@@ -403,9 +403,7 @@ def toVTKAssy(
             if element.material.pbr:
                 actor.GetProperty().SetMetallic(element.material.pbr.metallic)
                 actor.GetProperty().SetRoughness(element.material.pbr.roughness)
-                actor.GetProperty().SetRefractionIndex(
-                    element.material.pbr.refraction_index
-                )
+                actor.GetProperty().SetBaseIOR(element.material.pbr.refraction_index)
                 if element.material.pbr.emissive_factor:
                     actor.GetProperty().SetEmissiveFactor(
                         *element.material.pbr.emissive_factor.rgb()

cadquery/occ_impl/exporters/assembly.py

@@ -30,7 +30,14 @@
 from OCP.Message import Message_ProgressRange
 from OCP.Interface import Interface_Static
 
-from ..assembly import AssemblyProtocol, color_to_occt, toCAF, toVTK, toFusedCAF
+from ..assembly import (
+    AssemblyProtocol,
+    color_to_occt,
+    toCAF,
+    toVTK,
+    toFusedCAF,
+    material_to_occt,
+)
 from ..geom import Location
 from ..shapes import Shape, Compound
 
@@ -139,6 +146,8 @@ def exportStepMeta(
     shape_tool = XCAFDoc_DocumentTool.ShapeTool_s(doc.Main())
     color_tool = XCAFDoc_DocumentTool.ColorTool_s(doc.Main())
     layer_tool = XCAFDoc_DocumentTool.LayerTool_s(doc.Main())
+    material_tool = XCAFDoc_DocumentTool.MaterialTool_s(doc.Main())
+    vis_material_tool = XCAFDoc_DocumentTool.VisMaterialTool_s(doc.Main())
 
     def _process_child(child: AssemblyProtocol, assy_label: TDF_Label):
         """
@@ -166,16 +175,46 @@ def _process_child(child: AssemblyProtocol, assy_label: TDF_Label):
                 child.name,
                 child.loc,
                 child.color,
+                child.material,
             )
 
         if child_items:
-            shape, name, loc, color = child_items
+            shape, name, loc, color, material = child_items
 
             # Handle shape name, color and location
             part_label = shape_tool.AddShape(shape.wrapped, False)
             TDataStd_Name.Set_s(part_label, TCollection_ExtendedString(name))
-            if color:
+
+            # Handle color and material
+            if material:
+                # Set color from material if available
+                if material.color:
+                    color_tool.SetColor(
+                        part_label, color_to_occt(material.color), XCAFDoc_ColorGen
+                    )
+
+                # Convert material to OCCT format and add to document
+                mat, vis_mat = material_to_occt(material)
+
+                # Create material label
+                mat_lab = material_tool.AddMaterial(
+                    mat.GetName(),
+                    mat.GetDescription(),
+                    mat.GetDensity(),
+                    mat.GetDensName(),
+                    mat.GetDensValType(),
+                )
+                material_tool.SetMaterial(part_label, mat_lab)
+
+                # Add visualization material to the document
+                vis_mat_lab = vis_material_tool.AddMaterial(
+                    vis_mat, TCollection_AsciiString(material.name)
+                )
+                vis_material_tool.SetShapeMaterial(part_label, vis_mat_lab)
+            elif color:
+                # If no material but color exists, set the color directly
                 color_tool.SetColor(part_label, color_to_occt(color), XCAFDoc_ColorGen)
+
             shape_tool.AddComponent(assy_label, part_label, loc.wrapped)
 
             # If this assembly has shape metadata, add it to the shape

examples/Ex027_Materials.py

@@ -1,4 +1,5 @@
 import cadquery as cq
+from cadquery.occ_impl.exporters.assembly import exportStepMeta
 
 # Create a simple cube
 cube = cq.Workplane().box(10, 10, 10)
@@ -69,9 +70,9 @@
 assy.add(cube.translate((45, 0, 0)), name="gold_cube", material=gold_material)
 
 # Export as OBJ and GLTF to showcase materials
-assy.export("materials.step")  # Step format
-assy.export("materials.gltf")  # Step format
-assy.export("materials.glb")  # GLTF format with PBR materials
+assy.export("materials.step")  # STEP format
+exportStepMeta(assy, "materials_meta.step")  # STEP format with metadata
+assy.export("materials.glb")  # GLTF format (binary) with PBR materials
 
 # Show the assembly in the UI
 show_object(assy)