Blender Python: Cleanup Modnao Model Imports

modnao_fix_imported_models.py

# Script by SuperFromND. Last updated 4/6/2024
# This was written to clean up exported model data from ModNao, a Sega Dreamcast model ripping website.
# License: CC0/WTFPL/Unlicense/whatever else you prefer to mean "public domain".
# No warranty or liability, do whatever you want, yada yada etc.

import bpy

# ========================================================
# Change this value if you're getting weird results from the merge-by-distance.
# Higher values = more aggressive merging.

threshold_value = 0.01
# ========================================================

# holds names of image textures, used to check dupe materials
image_mats = []

# reset selected objects
bpy.ops.object.select_all(action="DESELECT")

print("Cleaning up materials...")
for obj in bpy.data.objects:
    if obj.type == "MESH" and not obj.active_material == None:
        for item in obj.material_slots:
            mat = bpy.data.materials[item.name]
            if mat.use_nodes:
                mat.blend_method = "CLIP"
                # first pass to just remove anything that's not necessary, i.e. we keep images and material out ONLY
                for node in mat.node_tree.nodes:
                    if node.type == "TEX_IMAGE" or node.type == "OUTPUT_MATERIAL":
                        # do nothing, but we keep this node
                        pass
                    else:
                        mat.node_tree.nodes.remove(node)

                # second pass to re-assemble the nodes into a normal material
                pbsdf = mat.node_tree.nodes.new("ShaderNodeBsdfPrincipled")
                matoutput = mat.node_tree.nodes.get("Material Output")
                for node in mat.node_tree.nodes:
                    if node.type == "TEX_IMAGE":
                        links = mat.node_tree.links
                        links.new(node.outputs[0], pbsdf.inputs["Base Color"])
                        links.new(node.outputs[1], pbsdf.inputs["Alpha"])
                        links.new(pbsdf.outputs["BSDF"], matoutput.inputs["Surface"])

                        # checks for duplicate materials based on image texture name
                        if node.image.name in image_mats:
                            for mat2 in bpy.data.materials:
                                if mat2.name == node.image.name:
                                    obj.data.materials[0] = mat2
                        else:
                            print(
                                "Unique image detected, creating material: "
                                + node.image.name
                            )
                            mat.name = node.image.name
                            image_mats.append(node.image.name)

# now it's time to cleanup the mesh data
# loop over top-level objects
print("Cleaning up meshes...")
root_objs = (obj for obj in bpy.context.scene.objects if not obj.parent)
for obj in root_objs:
    if obj.children == None:
        continue
    else:
        for child in obj.children:
            # this should be all the "object" nodes, which contain more empties and meshes respectively
            obj_name = child.name
            mesh_list = []

            # fetch all meshes (assuming structure is consistent PLEASE BE CONSISTENT AAAAA)
            for obj_empty in child.children:
                for obj_mesh in obj_empty.children:
                    mesh_list.append(obj_mesh)

            for objz in mesh_list:
                objz.select_set(True)

            # clear their parents but keep transforms
            bpy.ops.object.parent_clear(type="CLEAR_KEEP_TRANSFORM")

            # check to see if there's meshes
            if len(mesh_list) == 0:
                continue
            else:
                print("Merging " + obj_name + "'s meshes...")
                # select first object in the mesh list and then join to that
                bpy.context.view_layer.objects.active = mesh_list[0]
                bpy.ops.object.join()

                # deselect all selected objects so it doesnt just make one huge mesh
                bpy.ops.object.select_all(action="DESELECT")

# final bit of cleanup: apply a merge-by-distance on every object and delete any remaining empties
for obj in bpy.data.objects:
    if obj.type == "EMPTY":
        bpy.data.objects.remove(obj)
    elif obj.type == "MESH":
        print("Applying merge-by-distance to " + obj.name + "...")
        obj.select_set(True)
        bpy.ops.object.mode_set(mode="EDIT")
        bpy.ops.mesh.select_mode(use_extend=False, use_expand=False, type="VERT")
        bpy.ops.mesh.select_all(action="SELECT")
        bpy.ops.mesh.remove_doubles(
            threshold=threshold_value,
            use_unselected=False,
            use_sharp_edge_from_normals=False,
        )
        obj.select_set(False)

# set back to object mode
bpy.ops.object.mode_set(mode="OBJECT")
print("Done. Have fun!")