mtlx2gltf.py

#!/usr/bin/env python
'''
Utility and command line interface to convert from a MaterialX file to a glTF file 
'''
import os
import argparse
 
from core import *
 
def mtlx2gltf(materialXFileName, gltfOutputFileName, options=MTLX2GLTFOptions()):
    '''
    Utility to convert a MaterialX file to glTF file
    @param materialXFileName Path to MaterialX file to convert
    @param gltfOutputFileName Path to glTF file to write
    @param options Options for conversion
    '''                        
    mtlx2glTFWriter = MTLX2GLTFWriter()
    doc, libFiles = Util.createMaterialXDoc()
    if libFiles:
        print('- Loaded %d library files.' % len(libFiles))
    else:
        print('- No library files loaded.')
    mx.readFromXmlFile(doc, materialXFileName, options['searchPath'])    
    
    mtlx2glTFWriter.setOptions(options)
 
    # Perform shader translation and baking if necessary
    if options['translateShaders']:
        translatedCount = mtlx2glTFWriter.translateShaders(doc)
        print('- Translated %d shaders.' % translatedCount)
        if options['bakeTextures']:
            print('- Baking start {')
            materialXFileName = materialXFileName + '_baked.mtlx'
            bakeResolution = 256
            if options['bakeResolution']:
                bakeResolution = options['bakeResolution']
            mtlx2glTFWriter.bakeTextures(doc, False, bakeResolution, bakeResolution, False, 
                                        False, False, materialXFileName)
            print('  - Baked textures to: ', materialXFileName)
            doc, libFiles = Util.createMaterialXDoc()
            mx.readFromXmlFile(doc, materialXFileName, options['searchPath'])
            remappedUris = Util.makeFilePathsRelative(doc, materialXFileName)
            for uri in remappedUris:
                print('  - Remapped URI: %s to %s' % (uri[0], uri[1]))
                Util.writeMaterialXDoc(doc, materialXFileName)
            print('- Baking end.')
 
    gltfString = mtlx2glTFWriter.convert(doc)
    if len(gltfString) > 0:
        print('> Write glTF to: ', gltfOutputFileName)
        f = open(gltfOutputFileName, 'w')
        f.write(gltfString)
        f.close()
    else:
        return False, mtlx2glTFWriter.getLog()
    
    if options['packageBinary']:
        binaryFileName = str(gltfOutputFileName)
        binaryFileName = binaryFileName.replace('.gltf', '.glb')
        print('- Packaging GLB file...')
        saved, images, buffers = mtlx2glTFWriter.packageGLTF(gltfOutputFileName, binaryFileName)
        print('- Save GLB file:' + binaryFileName + '. Status:' + str(saved))
        for image in images:
            print('  - Embedded image: %s' % image)
        for buffer in buffers:
            print('  - Embedded buffer: %s' % buffer)
 
    return True, ''
 
def main():
    '''
    Command line utility to convert a MaterialX file to a glTF file
    '''
    parser = argparse.ArgumentParser(description='Utility to convert a MaterialX file to a glTF file')
    parser.add_argument(dest='mtlxFileName', help='Path containing MaterialX file to convert.')
    parser.add_argument('--gltfFileName', dest='gltfFileName', default='', help='Name of MaterialX output file. If not specified the glTF name with "_tomtlx.mtlx" suffix will be used')
    parser.add_argument('--gltfGeomFileName', dest='gltfGeomFileName', default='', help='Name of MaterialX output file. If not specified the glTF name with "_tomtlx.mtlx" suffix will be used')
    parser.add_argument('--primsPerMaterial', dest='primsPerMaterial', type=mx.stringToBoolean, default=False, help='Create a new primitive per material and assign the material. Default is False')
    parser.add_argument('--packageBinary', dest='packageBinary', type=mx.stringToBoolean, default=False, help='Create a biary packaged GLB file. Default is False')
    parser.add_argument('--translateShaders', dest='translateShaders', type=mx.stringToBoolean, default=False, help='Translate shaders to glTF. Default is False')
    parser.add_argument('--bakeTextures', dest='bakeTextures', type=mx.stringToBoolean, default=False, help='Bake pattern graphs as textures. Default is False')
    parser.add_argument('--bakeResolution', dest='bakeResolution', type=int, default=256, help='Bake image resolution. Default is 256')
    parser.add_argument('--writeDefaultInputs', dest='writeDefaultInputs', type=mx.stringToBoolean, default=False, help='Write default inputs on shader nodes. Default is False')
 
    opts = parser.parse_args()
 
    # Check input glTF file
    mtlxFileName = opts.mtlxFileName
    if not os.path.exists(mtlxFileName):
        print('Cannot find input file: ', mtlxFileName)
        exit(-1)    
 
    # If a folder is specified then collect all MaterialX files in the folder
    mtlxFiles = []
    ignoreGltfFileName = False
    if mx.FilePath(mtlxFileName).isDirectory():
        for file in os.listdir(mtlxFileName):
            if file.endswith('.mtlx'):
                mtlxFiles.append(os.path.join(mtlxFileName, file))
        if len(mtlxFiles) == 0:
            print('No MaterialX files found in folder: ', mtlxFileName)
            exit(-1)
        ignoreGltfFileName = True
    else:
        mtlxFiles.append(mtlxFileName)
 
    for mtlxFileName in mtlxFiles:
        if len(mtlxFiles) > 1:
            print('*** Converting MaterialX file:', mtlxFileName)
 
        # Set up MTLX file name
        gltfFileName = mtlxFileName + '.gltf'
        if not ignoreGltfFileName and len(opts.gltfFileName) > 0:
            gltfFileName = opts.gltfFileName 
 
        # Perform conversion
        options = MTLX2GLTFOptions()
        options['primsPerMaterial'] = opts.primsPerMaterial
        options['packageBinary'] = opts.packageBinary
        gltfGeomFileName = opts.gltfGeomFileName
        if len(gltfGeomFileName) > 0:
            if not mx.FilePath(gltfGeomFileName).isAbsolute():
                gltfGeomFileName = os.path.abspath(gltfGeomFileName)        
        options['geometryFile'] = opts.gltfGeomFileName
        options['translateShaders'] = opts.translateShaders
        options['bakeTextures'] = opts.bakeTextures
        options['bakeResolution'] = opts.bakeResolution
        options['writeDefaultInputs'] = opts.writeDefaultInputs
 
        # Set search path to default library path as well as folder containing MaterialX file
        # and current path
        searchPath = mx.getDefaultDataSearchPath()
        if not mx.FilePath(mtlxFileName).isAbsolute():
            mtlxFileName = os.path.abspath(mtlxFileName)
        searchPath.append(mx.FilePath(mtlxFileName).getParentPath())
        searchPath.append(mx.FilePath.getCurrentPath())
        searchPath.append(mx.FilePath(gltfGeomFileName).getParentPath())
        options['searchPath'] = searchPath
 
        print("- Search path set to:", searchPath.asString())         
        converted, err = mtlx2gltf(mtlxFileName, gltfFileName, options)
        print('Converted MaterialX file %s to gltf file: %s. Status: %s.' % (mtlxFileName, gltfFileName, converted))
        if not converted:
            print('- Error: ', err)
 
if __name__ == "__main__":
    main()