Add in mxgltf.py utility script.

python/Scripts/mxgltf.py

@@ -0,0 +1,111 @@
+#!/usr/bin/env python
+'''
+MaterialX glTF bi-directional conversion utility.
+
+If a MaterialX document is provided as input, the utility will convert to glTF,
+otherwise if a glTF file is provided as input, the utility will convert to MaterialX.
+
+Copyright 2022 - 2023 Bernard Kwok
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+http ://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+'''
+
+import sys, os, io, argparse
+import MaterialX as mx
+import MaterialX.PyMaterialXRender as mx_gltf
+
+def skipLibraryElement(elem):
+    return not elem.hasSourceUri()
+
+def main():
+    parser = argparse.ArgumentParser(description="MaterialX glTF converter")
+    parser.add_argument(dest="inputFilename", help="Filename of the input document (glTF or MaterialX).")
+    opts = parser.parse_args()
+
+    inputFilename = opts.inputFilename
+    if not os.path.isfile(inputFilename):
+        print('Input file not found: ' + inputFilename)
+        return
+
+    inputFilePath = mx.FilePath(inputFilename)
+
+    toGLTF = inputFilePath.getExtension() == 'mtlx'
+    toMaterialX = inputFilePath.getExtension() == 'gltf'
+
+    if not toGLTF and not toMaterialX:
+        print('Input file must be glTF or MaterialX')
+        return
+
+    handler = mx_gltf.GltfMaterialHandler()
+    if not handler:
+        print('Failed to create GltfMaterialHandler')
+        return
+
+    log = []
+
+    # Convert from Materialx to GLTF
+    if toGLTF:
+        doc = mx.createDocument()
+        mx.readFromXmlFile(doc, inputFilePath)
+        outputFilePath = inputFilePath
+        print('Converting MaterialX file:%s to glTF file: %s' % 
+              (inputFilePath.asString(), outputFilePath.asString() + '.gltf'))
+        handler.setMaterials(doc);
+        converted = handler.save(outputFilePath.asString() + '.gltf', log);    
+        print("- Converted: " + str(converted))
+        if not converted:
+            print("- Log: " + '\n'.join(log))
+
+    # Convert from GLTF to MaterialX
+    elif toMaterialX:
+        stdlib = mx.createDocument()
+        searchPath = mx.getDefaultDataSearchPath()
+        libraryFolders = []
+        libraryFolders.extend(mx.getDefaultDataLibraryFolders())
+        try:
+            mx.loadLibraries(libraryFolders, searchPath, stdlib)
+        except mx.Exception as err:
+            print('Failed to load standard libraries: "', err, '"')
+            sys.exit(-1)
+
+        outputFilePath = mx.FilePath()
+        outputFilePath = inputFilePath
+        print('Converting glTF file:%s to MaterialX file: %s' % 
+              (inputFilePath.asString(), inputFilePath.asString()+".mtlx"))
+
+        createAssignments = False
+        fullDefinition = False
+        handler.setDefinitions(stdlib)
+        handler.setGenerateAssignments(createAssignments)
+        handler.setGenerateFullDefinitions(fullDefinition)
+
+        loadedMaterial = handler.load(inputFilePath, log)
+        print("- Loaded GLTF file: " + str(loadedMaterial))
+        doc = None
+        if loadedMaterial:
+            doc = handler.getMaterials() 
+        if doc:
+            # Filter out standard library elements
+            writeOptions = mx.XmlWriteOptions()
+            writeOptions.writeXIncludeEnable = False
+            writeOptions.elementPredicate = skipLibraryElement
+            mx.writeToXmlFile(doc, inputFilePath.asString()+".mtlx", writeOptions)
+
+        print("- Converted: " + str(doc != None))
+
+    if log:
+        print("Log" + '\n'.join(log))
+
+
+if __name__ == '__main__':
+    main()