Referenced shader attributes issue

lib/mayaUsd/utils/util.cpp

@@ -1210,6 +1210,14 @@ bool UsdMayaUtil::IsAuthored(const MPlug& plug)
     // make a copy of plug here.
     MPlug plugCopy(plug);
 
+    // MPlug::isFromReferencedFile did not seem to be accurate, so this checks the node state.
+    // If the node is referenced, use MPlug::isDefaultValue - it is not clear if isDefaultValue
+    // works in all contexts as the code below uses MPlug::getSetAttrCmds.
+    //
+    MFnDependencyNode nodeFn(plug.node());
+    if (nodeFn.isFromReferencedFile() && !plug.isDefaultValue())
+        return true;
+
     MStringArray setAttrCmds;
     status = plugCopy.getSetAttrCmds(setAttrCmds, MPlug::kChanged);
     CHECK_MSTATUS_AND_RETURN(status, false);

test/lib/usd/translators/CMakeLists.txt

@@ -1,4 +1,5 @@
 set(TEST_SCRIPT_FILES
+    testUsdExport8BitNormalMap.py
     testUsdExportAnimation.py
     testUsdExportAsClip.py
     testUsdExportBindTransform.py

test/lib/usd/translators/testUsdExport8BitNormalMap.py

@@ -0,0 +1,115 @@
+#!/usr/bin/env mayapy
+#
+# Copyright 2018 Pixar
+#
+# 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 os
+import unittest
+import base64
+
+from maya import cmds
+from maya import standalone
+
+from pxr import Usd,UsdShade,Gf
+
+import fixturesUtils
+
+TEST_NORMAL_MAP = """iVBORw0KGgoAAAANSUhEUgAAAAgAAAAICAYAAADED76LAAAAAXNSR0IArs4c6QAAADhlWElmTU0A
+KgAAAAgAAYdpAAQAAAABAAAAGgAAAAAAAqACAAQAAAABAAAACKADAAQAAAABAAAACAAAAAC2TFlo
+AAAAHGlET1QAAAACAAAAAAAAAAQAAAAoAAAABAAAAAQAAABOcQ0LgQAAABpJREFUKBViKCoq+o+M
+/6MBBmRJEBsdUK4AAAAA//9KAo7WAAAAGUlEQVRj+I8GioqK/iNjBjR5FEmQQsoVAAAlMMohT07s
+XwAAAABJRU5ErkJggg=="""
+
+
+def build_scene():
+    cmds.file(f=1, new=1)
+    plane = cmds.polyPlane()
+    print(plane)
+    shader = cmds.shadingNode('usdPreviewSurface', asShader=True, name='usdPreviewSurface1')
+    cmds.select(cl=1)
+    sg = cmds.sets(renderable=True, noSurfaceShader=True, name='usdPreviewSurface1SG')
+    cmds.connectAttr('{}.outColor'.format(shader) ,'{}.surfaceShader'.format(sg))
+
+    cmds.createNode('place2dTexture', name="place2dTexture1")
+    file_node = cmds.createNode('file', name='file1')
+
+    cmds.connectAttr("place2dTexture1.c", "file1.c")
+    cmds.connectAttr("place2dTexture1.tf", "file1.tf")
+    cmds.connectAttr("place2dTexture1.rf", "file1.rf")
+    cmds.connectAttr("place2dTexture1.mu", "file1.mu")
+    cmds.connectAttr("place2dTexture1.mv", "file1.mv")
+    cmds.connectAttr("place2dTexture1.s", "file1.s")
+    cmds.connectAttr("place2dTexture1.wu", "file1.wu")
+    cmds.connectAttr("place2dTexture1.wv", "file1.wv")
+    cmds.connectAttr("place2dTexture1.re", "file1.re")
+    cmds.connectAttr("place2dTexture1.of", "file1.of")
+    cmds.connectAttr("place2dTexture1.r", "file1.ro")
+    cmds.connectAttr("place2dTexture1.n", "file1.n")
+    cmds.connectAttr("place2dTexture1.vt1", "file1.vt1")
+    cmds.connectAttr("place2dTexture1.vt2", "file1.vt2")
+    cmds.connectAttr("place2dTexture1.vt3", "file1.vt3")
+    cmds.connectAttr("place2dTexture1.vc1", "file1.vc1")
+    cmds.connectAttr("place2dTexture1.o", "file1.uv")
+    cmds.connectAttr("place2dTexture1.ofs", "file1.fs")
+    cmds.connectAttr("file1.oc", "usdPreviewSurface1.nrm")
+
+    cmds.sets('pPlane1', e=1, fe=sg)
+    return file_node
+
+def build_test_scene(out_dir):
+    """Build test scene with reference"""
+    fnode = build_scene()
+    out_file = os.path.join(out_dir, 'test_scene.mb')
+    out_tex = os.path.join(out_dir, 'test_tex.png')
+    with open(out_tex, 'wb') as out:
+        out.write(base64.b64decode(TEST_NORMAL_MAP))
+    cmds.setAttr(fnode+'.ftn', out_tex, type='string')
+
+    cmds.file(rename=out_file)
+    cmds.file(f=1, save=1, type='mayaBinary')
+
+    cmds.file(f=1, new=1)
+    cmds.file(out_file, reference=True, namespace='ref')
+
+
+
+class testExport8BitNormalMap(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.inputPath = fixturesUtils.setUpClass(__file__)
+        cls.temp_dir = os.path.abspath('.')
+
+    @classmethod
+    def tearDownClass(cls):
+        standalone.uninitialize()
+
+    def test_export(self):
+        """Check to see if inputs:scale is set to [2, 2, 2, 1] and inputs:bias is [-1, -1, -1, 0]"""
+        build_test_scene(self.temp_dir)
+
+        out_file = os.path.abspath('normalMapTest.usdc')
+        cmds.mayaUSDExport(file=out_file,)
+
+        self.assertTrue(os.path.isfile(out_file))
+
+        stage = Usd.Stage.Open(out_file)
+        shader = UsdShade.Shader.Get(stage, '/ref_pPlane1/Looks/ref_usdPreviewSurface1SG/ref_file1')
+
+        self.assertEqual(Gf.Vec4f(-1, -1, -1, 0), shader.GetInput('bias').Get())
+        self.assertEqual(Gf.Vec4f(2, 2, 2, 1), shader.GetInput('scale').Get())
+
+
+if __name__ == '__main__':
+    unittest.main(verbosity=2)