Add Opacity Threshold Attribute to USD Preview Shader

Autodesk · Nov 16, 2020 · 9578137 · 9578137
1 parent fc769db
commit 9578137
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Showing 6 changed files with 52 additions and 1 deletion.
diff --git a/lib/usd/pxrUsdPreviewSurface/AEusdPreviewSurfaceTemplate.mel b/lib/usd/pxrUsdPreviewSurface/AEusdPreviewSurfaceTemplate.mel
@@ -41,6 +41,7 @@ global proc AE${PREVIEWSURFACE_MAYA_TYPE_NAME}Template(string $nodeName)
     editorTemplate -addControl "emissiveColor";
     editorTemplate -addControl "occlusion";
     editorTemplate -addControl "opacity";
+    editorTemplate -addControl "opacityThreshold";
 
     editorTemplate -beginLayout "Specular" -collapse false;
         editorTemplate -addControl "useSpecularWorkflow"

diff --git a/lib/usd/pxrUsdPreviewSurface/usdPreviewSurface.cpp b/lib/usd/pxrUsdPreviewSurface/usdPreviewSurface.cpp
@@ -42,6 +42,7 @@ TF_DEFINE_PUBLIC_TOKENS(
     PxrMayaUsdPreviewSurfaceTokens,
     PXRUSDPREVIEWSURFACE_USD_PREVIEW_SURFACE_TOKENS);
 
+
 /* static */
 void* PxrMayaUsdPreviewSurface::creator() { return new PxrMayaUsdPreviewSurface(); }
 
@@ -60,6 +61,7 @@ MStatus PxrMayaUsdPreviewSurface::initialize()
     MObject normalAttr;
     MObject occlusionAttr;
     MObject opacityAttr;
+    MObject opacityThresholdAttr;
     MObject roughnessAttr;
     MObject specularColorAttr;
     MObject useSpecularWorkflowAttr;
@@ -228,6 +230,24 @@ MStatus PxrMayaUsdPreviewSurface::initialize()
     status = addAttribute(opacityAttr);
     CHECK_MSTATUS_AND_RETURN_IT(status);
 
+    opacityThresholdAttr = numericAttrFn.create(
+        PxrMayaUsdPreviewSurfaceTokens->OpacityThresholdAttrName.GetText(),
+        "opt",
+        MFnNumericData::kFloat,
+        0.0,
+        &status);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
+    status = numericAttrFn.setSoftMin(0.0);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
+    status = numericAttrFn.setSoftMax(1.0);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
+    status = numericAttrFn.setKeyable(true);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
+    status = numericAttrFn.setAffectsAppearance(true);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
+    status = addAttribute(opacityThresholdAttr);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
+
     roughnessAttr = numericAttrFn.create(
         PxrMayaUsdPreviewSurfaceTokens->RoughnessAttrName.GetText(),
         "rgh",
@@ -345,6 +365,8 @@ MStatus PxrMayaUsdPreviewSurface::initialize()
     CHECK_MSTATUS_AND_RETURN_IT(status);
     status = attributeAffects(opacityAttr, outColorAttr);
     CHECK_MSTATUS_AND_RETURN_IT(status);
+    status = attributeAffects(opacityThresholdAttr, outColorAttr);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
     status = attributeAffects(roughnessAttr, outColorAttr);
     CHECK_MSTATUS_AND_RETURN_IT(status);
     status = attributeAffects(specularColorAttr, outColorAttr);
@@ -354,6 +376,8 @@ MStatus PxrMayaUsdPreviewSurface::initialize()
 
     status = attributeAffects(opacityAttr, outTransparencyAttr);
     CHECK_MSTATUS_AND_RETURN_IT(status);
+    status = attributeAffects(opacityThresholdAttr, outTransparencyAttr);
+    CHECK_MSTATUS_AND_RETURN_IT(status);
 
     status = attributeAffects(opacityAttr, outTransparencyOnAttr);
     CHECK_MSTATUS_AND_RETURN_IT(status);
@@ -399,7 +423,18 @@ MStatus PxrMayaUsdPreviewSurface::compute(const MPlug& plug, MDataBlock& dataBlo
             = depNodeFn.attribute(PxrMayaUsdPreviewSurfaceTokens->OpacityAttrName.GetText());
         const MDataHandle opacityData = dataBlock.inputValue(opacityAttr, &status);
         CHECK_MSTATUS(status);
-        const float opacity = opacityData.asFloat();
+        float opacity = opacityData.asFloat();
+
+        MObject opacityThresholdAttr
+            = depNodeFn.attribute(PxrMayaUsdPreviewSurfaceTokens->OpacityThresholdAttrName.GetText());
+        const MDataHandle opacityThresholdData
+            = dataBlock.inputValue(opacityThresholdAttr, &status);
+        CHECK_MSTATUS(status);
+        const float opacityThreshold = opacityThresholdData.asFloat();
+
+        if (opacity < opacityThreshold) {
+            opacity = 0.0f;
+        }
 
         const float        transparency = 1.0f - opacity;
         const MFloatVector transparencyColor(transparency, transparency, transparency);

diff --git a/lib/usd/pxrUsdPreviewSurface/usdPreviewSurface.h b/lib/usd/pxrUsdPreviewSurface/usdPreviewSurface.h
@@ -45,6 +45,7 @@ PXR_NAMESPACE_OPEN_SCOPE
     ((NormalAttrName, "normal"))                                                                 \
     ((OcclusionAttrName, "occlusion"))                                                           \
     ((OpacityAttrName, "opacity"))                                                               \
+    ((OpacityThresholdAttrName, "opacityThreshold"))                                             \
     ((RoughnessAttrName, "roughness"))                                                           \
     ((SpecularColorAttrName, "specularColor"))                                                   \
     ((UseSpecularWorkflowAttrName, "useSpecularWorkflow"))                                       \
@@ -82,6 +83,7 @@ class PxrMayaUsdPreviewSurface : public MPxNode
 
     PxrMayaUsdPreviewSurface(const PxrMayaUsdPreviewSurface&) = delete;
     PxrMayaUsdPreviewSurface& operator=(const PxrMayaUsdPreviewSurface&) = delete;
+    MObject opacityThresholdAttr;
 };
 
 PXR_NAMESPACE_CLOSE_SCOPE

diff --git a/lib/usd/pxrUsdPreviewSurface/usdPreviewSurfaceReader.cpp b/lib/usd/pxrUsdPreviewSurface/usdPreviewSurfaceReader.cpp
@@ -137,6 +137,7 @@ TfToken PxrMayaUsdPreviewSurface_Reader::GetMayaNameForUsdAttrName(const TfToken
             || baseName == PxrMayaUsdPreviewSurfaceTokens->NormalAttrName
             || baseName == PxrMayaUsdPreviewSurfaceTokens->OcclusionAttrName
             || baseName == PxrMayaUsdPreviewSurfaceTokens->OpacityAttrName
+            || baseName == PxrMayaUsdPreviewSurfaceTokens->OpacityThresholdAttrName
             || baseName == PxrMayaUsdPreviewSurfaceTokens->RoughnessAttrName
             || baseName == PxrMayaUsdPreviewSurfaceTokens->SpecularColorAttrName
             || baseName == PxrMayaUsdPreviewSurfaceTokens->UseSpecularWorkflowAttrName) {

diff --git a/lib/usd/pxrUsdPreviewSurface/usdPreviewSurfaceWriter.cpp b/lib/usd/pxrUsdPreviewSurface/usdPreviewSurfaceWriter.cpp
@@ -253,6 +253,14 @@ void PxrMayaUsdPreviewSurface_Writer::Write(const UsdTimeCode& usdTime)
         SdfValueTypeNames->Float,
         usdTime);
 
+    // Opacity Threshold
+    _AuthorShaderInputFromShadingNodeAttr(
+        depNodeFn,
+        shaderSchema,
+        PxrMayaUsdPreviewSurfaceTokens->OpacityThresholdAttrName,
+        SdfValueTypeNames->Float,
+        usdTime);
+
     // Roughness
     _AuthorShaderInputFromShadingNodeAttr(
         depNodeFn,
@@ -306,6 +314,7 @@ PxrMayaUsdPreviewSurface_Writer::GetShadingAttributeNameForMayaAttrName(const Tf
         || mayaAttrName == PxrMayaUsdPreviewSurfaceTokens->NormalAttrName
         || mayaAttrName == PxrMayaUsdPreviewSurfaceTokens->OcclusionAttrName
         || mayaAttrName == PxrMayaUsdPreviewSurfaceTokens->OpacityAttrName
+        || mayaAttrName == PxrMayaUsdPreviewSurfaceTokens->OpacityThresholdAttrName
         || mayaAttrName == PxrMayaUsdPreviewSurfaceTokens->RoughnessAttrName
         || mayaAttrName == PxrMayaUsdPreviewSurfaceTokens->SpecularColorAttrName
         || mayaAttrName == PxrMayaUsdPreviewSurfaceTokens->UseSpecularWorkflowAttrName) {

diff --git a/test/lib/usd/translators/testUsdExportImportRoundtripPreviewSurface.py b/test/lib/usd/translators/testUsdExportImportRoundtripPreviewSurface.py
@@ -68,6 +68,7 @@ def testUsdPreviewSurfaceRoundtrip(self):
         cmds.setAttr(material_node + ".specularColor", 0.125, 0.25, 0.75,
                      type="double3")
         cmds.setAttr(material_node + ".useSpecularWorkflow", True)
+        cmds.setAttr(material_node + ".opacityThreshold", 0.5)
 
         file_node = cmds.shadingNode("file", asTexture=True,
                                      isColorManaged=True)
@@ -131,6 +132,8 @@ def testUsdPreviewSurfaceRoundtrip(self):
         # Check values:
         self.assertAlmostEqual(cmds.getAttr("usdPreviewSurface2.roughness"),
                                0.25)
+        self.assertAlmostEqual(cmds.getAttr("usdPreviewSurface2.opacityThreshold"),
+                               0.5)
         self.assertEqual(cmds.getAttr("usdPreviewSurface2.specularColor"),
                          [(0.125, 0.25, 0.75)])
         self.assertTrue(cmds.getAttr("usdPreviewSurface2.useSpecularWorkflow"))