w3d properties internal rename, multiple material per mesh object support, alpha transparency support, empty data object error fix (#261)

* __init__.py: blend_mode fixed to blend_method

Renamed from blend_mode to blend_method in accordance with blender internals

* material_import.py: Alpha Clip blend method for working transparency

* material_import.py: Added support for Multiple Materials per Mesh Object

Based on makarenk0's implementation, now with alpha transparency support.

* Update mesh_import.py: Multiple Material per Mesh Object support

+1 Argument to create_vertex_material in \material_import.py

* material_import.py: alpha clip blend mode for multiple material meshes

* Create an empty UV Map on early return

This is to ensure no export errors due to empty object data in certain formats. (One example would be an error thrown on Airfield Imports due to the HOUSECOLOR01 material not having an UV Map attached.)

* material_import.py: Fixed material duplication, node_tree manipulation

* autopep8 action fixes

* helpers.py : create_uvlayer, check if mesh exists

* Update material_pass.py

* Update material_pass.py

* tests/material_pass.py get_texture_stage() : attempt at per face texture id enumeration

* Update material_pass.py

* Update material_import.py

* Update material_import.py

* Update material_import.py

* autopep8 action fixes

---------

Co-authored-by: rizzntine <rizzntine@users.noreply.github.com>

Author: rizzntine

io_mesh_w3d/__init__.py

@@ -298,7 +298,7 @@ def draw(self, context):
         col = layout.column()
         col.prop(mat, 'surface_type')
         col = layout.column()
-        col.prop(mat, 'blend_mode')
+        col.prop(mat, 'blend_method')
         col = layout.column()
         col.prop(mat, 'ambient')
 
@@ -370,7 +370,7 @@ def draw(self, context):
             col = layout.column()
             col.prop(mat, 'damaged_texture')
             col = layout.column()
-            col.prop(mat, 'secondary_texture_blend_mode')
+            col.prop(mat, 'secondary_texture_blend_method')
             col = layout.column()
             col.prop(mat, 'tex_coord_mapper_0')
             col = layout.column()

io_mesh_w3d/common/utils/helpers.py

@@ -82,6 +82,8 @@ def create_uvlayer(context, mesh, b_mesh, tris, mat_pass):
             context.warning('only one texture stage per material pass supported')
 
     if tx_coords is None:
+        if mesh is not None:
+            uv_layer = mesh.uv_layers.new(do_init=False)
         return
 
     uv_layer = mesh.uv_layers.new(do_init=False)
@@ -96,6 +98,7 @@ def create_uvlayer_2(context, mesh, b_mesh, tris, mat_pass):
     if mat_pass.tx_coords_2:
         tx_coords_2 = mat_pass.tx_coords_2
     else:
+        uv_layer = mesh.uv_layers.new(do_init=False)
         return
 
     uv_layer = mesh.uv_layers.new(do_init=False)

io_mesh_w3d/common/utils/material_import.py

@@ -13,24 +13,71 @@
 # vertex material
 ##########################################################################
 
-def create_vertex_material(context, principleds, structure, mesh, b_mesh, name, triangles):
-    for vertMat in structure.vert_materials:
-        (material, principled) = create_material_from_vertex_material(name, vertMat)
-        mesh.materials.append(material)
-        principleds.append(principled)
-
-    for mat_pass in structure.material_passes:
-        create_uvlayer(context, mesh, b_mesh, triangles, mat_pass)
-        create_uvlayer_2(context, mesh, b_mesh, triangles, mat_pass)
-
-        if mat_pass.tx_stages:
-            tx_stage = mat_pass.tx_stages[0]
-            mat_id = mat_pass.vertex_material_ids[0]
-            tex_id = tx_stage.tx_ids[0][0]
+def create_vertex_material(context, principleds, structure, mesh, b_mesh, name, triangles, mesh_ob):
+
+    if len(structure.material_passes) == 1 and len(
+            structure.textures) > 1:  # condition for multiple materials per single mesh object
+        # Create the same amount of materials as textures used for this mesh
+        source_mat = structure.vert_materials[0]
+        for texture in structure.textures:
+            source_mat.vm_name = texture.id
+            (material, principled) = create_material_from_vertex_material(name, source_mat)
+            mesh.materials.append(material)
+            principleds.append(principled)
+
+        create_uvlayer(context, mesh, b_mesh, triangles, structure.material_passes[0])
+
+        # Load textures
+        for tex_id, texture in enumerate(structure.textures):
             texture = structure.textures[tex_id]
             tex = find_texture(context, texture.file, texture.id)
-            principleds[mat_id].base_color_texture.image = tex
-            principleds[mat_id].base_color_texture.image.name = texture.file
+            node_tree = mesh.materials[tex_id].node_tree
+            bsdf_node = node_tree.nodes.get('Principled BSDF')
+            texture_node = node_tree.nodes.new('ShaderNodeTexImage')
+            texture_node.image = tex
+            texture_node.location = (-350, 300)
+            links = node_tree.links
+            links.new(texture_node.outputs['Color'], bsdf_node.inputs['Base Color'])
+            links.new(texture_node.outputs['Alpha'], bsdf_node.inputs['Alpha'])
+
+        # Assign material to appropriate object faces
+        bpy.ops.object.mode_set(mode='EDIT')
+        bm = bmesh.from_edit_mesh(mesh_ob.data)
+        bm.faces.ensure_lookup_table()
+        for i, face in enumerate(bm.faces):
+            if(i < len(structure.material_passes[0].tx_stages[0].tx_ids[0])):
+                bm.faces[i].material_index = structure.material_passes[0].tx_stages[0].tx_ids[0][i]
+            else:
+                bm.faces[i].material_index = structure.material_passes[0].tx_stages[0].tx_ids[0][0]
+        bpy.ops.object.mode_set(mode='OBJECT')
+    else:
+        for vertMat in structure.vert_materials:
+            (material, principled) = create_material_from_vertex_material(name, vertMat)
+            mesh.materials.append(material)
+            principleds.append(principled)
+
+        for mat_pass in structure.material_passes:
+            create_uvlayer(context, mesh, b_mesh, triangles, mat_pass)
+
+            if mat_pass.tx_stages:
+                tx_stage = mat_pass.tx_stages[0]
+                mat_id = mat_pass.vertex_material_ids[0]
+                tex_id = tx_stage.tx_ids[0][0]
+                texture = structure.textures[tex_id]
+                tex = find_texture(context, texture.file, texture.id)
+                node_tree = mesh.materials[tex_id].node_tree
+                bsdf_node = node_tree.nodes.get('Principled BSDF')
+                texture_node = node_tree.nodes.new('ShaderNodeTexImage')
+                texture_node.image = tex
+                texture_node.location = (-350, 300)
+                links = node_tree.links
+                links.new(texture_node.outputs['Color'], bsdf_node.inputs['Base Color'])
+                links.new(texture_node.outputs['Alpha'], bsdf_node.inputs['Alpha'])
+
+    # Iterate through all materials and set their blend mode to Alpha Clip for transparency
+    for material in mesh.materials:
+        if material:
+            material.blend_method = 'CLIP'
 
 
 def create_material_from_vertex_material(name, vert_mat):
@@ -43,7 +90,6 @@ def create_material_from_vertex_material(name, vert_mat):
     material = bpy.data.materials.new(name)
     material.material_type = 'VERTEX_MATERIAL'
     material.use_nodes = True
-    material.blend_method = 'BLEND'
     material.show_transparent_back = False
 
     attributes = {'DEFAULT'}
@@ -91,7 +137,6 @@ def create_material_from_shader_material(context, name, shader_mat):
     material = bpy.data.materials.new(name)
     material.material_type = 'SHADER_MATERIAL'
     material.use_nodes = True
-    material.blend_method = 'BLEND'
     material.show_transparent_back = False
 
     material.technique = shader_mat.header.technique

io_mesh_w3d/common/utils/mesh_import.py

@@ -83,14 +83,14 @@ def create_mesh(context, mesh_struct, coll):
 
     if mesh_struct.vert_materials:
         create_vertex_material(
-            context, principleds, mesh_struct, mesh, b_mesh, actual_mesh_name, triangles)
+            context, principleds, mesh_struct, mesh, b_mesh, actual_mesh_name, triangles, mesh_ob)
 
         for i, shader in enumerate(mesh_struct.shaders):
             set_shader_properties(mesh.materials[min(i, len(mesh.materials) - 1)], shader)
 
     elif mesh_struct.prelit_vertex:
         create_vertex_material(context, principleds, mesh_struct.prelit_vertex,
-                               mesh, b_mesh, actual_mesh_name, triangles)
+                               mesh, b_mesh, actual_mesh_name, triangles, mesh_ob)
 
         for i, shader in enumerate(mesh_struct.prelit_vertex.shaders):
             set_shader_properties(mesh.materials[i], shader)

tests/w3d/helpers/mesh_structs/material_pass.py

@@ -30,7 +30,7 @@ def get_per_face_txcoords():
 
 def get_texture_stage(index=0):
     return TextureStage(
-        tx_ids=[[index]],
+        tx_ids=[[index] + [index] * max(0, index - 1)],
         per_face_tx_coords=[get_per_face_txcoords()],
         tx_coords=[get_uvs()])