This Python script converts FBX textures/materials to the s&box game format. Converting materials to VMAT, and extracting textures to the selected folder

fbx_to_vmat_converter.py

#This Python script converts FBX textures/materials to the s&box game format. Converting materials to VMAT, and extracting textures to the selected folder
#This script expects all the textures to be located at the same folder as the FBX file

import fbx
import os
import shutil
import tkinter as tk
from tkinter import filedialog

# Initialize tkinter
root = tk.Tk()
root.withdraw()  # Hide the main window

# Select FBX file
fbx_file = filedialog.askopenfilename(title="Select FBX File", filetypes=[("FBX files", "*.fbx")])
if not fbx_file:
    print("No FBX file selected.")
    exit(1)

# Select output directory for VMAT files
output_dir = filedialog.askdirectory(title="Select Output Directory for VMAT Files")
if not output_dir:
    print("No output directory selected.")
    exit(1)

# Initialize FBX SDK
manager = fbx.FbxManager.Create()
importer = fbx.FbxImporter.Create(manager, "")
if not importer.Initialize(fbx_file):
    print("Failed to initialize FBX importer.")
    exit(1)
scene = fbx.FbxScene.Create(manager, "")
if not importer.Import(scene):
    print("Failed to import FBX scene.")
    exit(1)

# Get the directory of the FBX file
fbx_dir = os.path.dirname(fbx_file)

# Function to copy texture to output folder with relative path
def copy_texture(texture_path, output_dir, fbx_dir):
    if not texture_path:
        return None
    rel_texture_path = os.path.basename(texture_path)
    abs_texture_path = os.path.join(fbx_dir, rel_texture_path)
    output_texture_path = os.path.join(output_dir, "textures", rel_texture_path)
    output_texture_dir = os.path.dirname(output_texture_path)
    os.makedirs(output_texture_dir, exist_ok=True)
    shutil.copy2(abs_texture_path, output_texture_path)
    return rel_texture_path.replace("\\", "/")

# Process each material in the scene
material_count = scene.GetMaterialCount()
for i in range(material_count):
    material = scene.GetMaterial(i)
    material_name = material.GetName()
    
    # Create VMAT file path
    vmat_file_path = os.path.join(output_dir, f"materials/{material_name}.vmat")
    output_material_dir = os.path.dirname(vmat_file_path)
    os.makedirs(output_material_dir, exist_ok=True)

    # Create and write to the .vmat file
    with open(vmat_file_path, "w") as vmat_file:
        vmat_file.write("// THIS FILE IS AUTO-GENERATED\n\n")
        vmat_file.write("Layer0\n{\n")
        vmat_file.write('\tshader "shaders/complex.shader"\n\n')
        
        # Ambient Occlusion - using defaults
        vmat_file.write('\t//---- Ambient Occlusion ----\n')
        vmat_file.write('\tg_flAmbientOcclusionDirectDiffuse "0.000"\n')
        vmat_file.write('\tg_flAmbientOcclusionDirectSpecular "0.000"\n')
        vmat_file.write('\tTextureAmbientOcclusion "materials/default/default_ao.tga"\n')
        
        # Color - map diffuse color and texture
        diffuse_color = material.Diffuse.Get()
        color_str = "[%.6f %.6f %.6f 1.000000]" % (diffuse_color[0], diffuse_color[1], diffuse_color[2])
        vmat_file.write('\n\t//---- Color ----\n')
        vmat_file.write('\tg_flModelTintAmount "1.000"\n')
        vmat_file.write(f'\tg_vColorTint "{color_str}"\n')
        
        diffuse_texture = material.Diffuse.GetSrcObject(0)
        if diffuse_texture:
            texture_path = diffuse_texture.GetRelativeFileName()
            rel_texture_path = copy_texture(texture_path, output_dir, fbx_dir)
            if rel_texture_path:
                vmat_file.write(f'\tTextureColor "textures/{rel_texture_path}"\n')
            else:
                vmat_file.write('\tTextureColor "materials/default/default_color.tga"\n')
        else:
            vmat_file.write('\tTextureColor "materials/default/default_color.tga"\n')
        
        # Fade - using default
        vmat_file.write('\n\t//---- Fade ----\n')
        vmat_file.write('\tg_flFadeExponent "1.000"\n')
        
        # Fog - using default
        vmat_file.write('\n\t//---- Fog ----\n')
        vmat_file.write('\tg_bFogEnabled "1"\n')
        
        # Metalness - using default
        vmat_file.write('\n\t//---- Metalness ----\n')
        vmat_file.write('\tg_flMetalness "0.000"\n')
        
        # Normal - map bump/normal map texture
        bump_prop = material.FindProperty("Bump")
        if bump_prop.IsValid():
            normal_texture = bump_prop.GetSrcObject(0)
            if normal_texture:
                texture_path = normal_texture.GetRelativeFileName()
                rel_texture_path = copy_texture(texture_path, output_dir, fbx_dir)
                if rel_texture_path:
                    vmat_file.write('\n\t//---- Normal ----\n')
                    vmat_file.write(f'\tTextureNormal "textures/{rel_texture_path}"\n')
                else:
                    vmat_file.write('\n\t//---- Normal ----\n')
                    vmat_file.write('\tTextureNormal "materials/default/default_normal.tga"\n')
            else:
                vmat_file.write('\n\t//---- Normal ----\n')
                vmat_file.write('\tTextureNormal "materials/default/default_normal.tga"\n')
        else:
            vmat_file.write('\n\t//---- Normal ----\n')
            vmat_file.write('\tTextureNormal "materials/default/default_normal.tga"\n')
        
        # Roughness - compute from shininess, use default texture
        shininess_prop = material.FindProperty("Shininess")
        if shininess_prop.IsValid():
            shininess_prop = fbx.FbxPropertyDouble1( shininess_prop )
            shininess = shininess_prop.Get()
            roughness = 1.0 - min(shininess / 100.0, 1.0)
        else:
            roughness = 1.0  # Default to maximum roughness
        vmat_file.write('\n\t//---- Roughness ----\n')
        vmat_file.write(f'\tg_flRoughnessScaleFactor "{roughness:.3f}"\n')
        vmat_file.write('\tTextureRoughness "materials/default/default_rough.tga"\n')
        
        # Texture Coordinates - using defaults
        vmat_file.write('\n\t//---- Texture Coordinates ----\n')
        vmat_file.write('\tg_nScaleTexCoordUByModelScaleAxis "0"\n')
        vmat_file.write('\tg_nScaleTexCoordVByModelScaleAxis "0"\n')
        vmat_file.write('\tg_vTexCoordOffset "[0.000 0.000]"\n')
        vmat_file.write('\tg_vTexCoordScale "[1.000 1.000]"\n')
        vmat_file.write('\tg_vTexCoordScrollSpeed "[0.000 0.000]"\n')
        
        vmat_file.write("}\n")

# Clean up FBX SDK resources
manager.Destroy()

print("VMAT files generated successfully.")