HYDRA-1760 : Support translation of maya extension attributes to hydra for lights, cameras and meshes by lanierd-adsk · Pull Request #398 · Autodesk/maya-hydra

lanierd-adsk · 2026-03-16T10:21:48Z

No description provided.

…ts, cameras and meshes

lanierd-adsk · 2026-03-16T10:38:40Z

lib/mayaHydra/hydraExtensions/adapters/renderItemAdapter.cpp

        MIndexBuffer* indices = geom->indexBuffer(0);
        if (indices) {
            int indexCount = indices->size();
-            vertexIndices.resize(indexCount);


Redundant with the line :
vertexIndices.assign(indicesData, indicesData + indexCount);

Copilot

Pull request overview

This PR extends Maya→Hydra primvar translation and dirtying behavior to better support extension/plugin attributes (notably Arnold ai*) across meshes, cameras, and lights, and adds/updates test coverage to validate translation + dirty-notice behavior.

Changes:

Refactors adapter dirtying to centralize “primvar dirty on attribute change” logic and reduce duplicate notifications (camera/light/mesh/render item).
Updates attribute extraction to optionally include broader attribute sets (for light/plugin attrs) and to skip default-valued attributes.
Adds new C++ + Python tests (and golden files) for mesh/camera/light primvars and Maya node attribute dirtying.

Reviewed changes

Copilot reviewed 38 out of 39 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/lib/mayaUsd/render/mayaToHydra/cpp/testUtils.h	Adds shared test helpers for prim lookup, optionVar reading, DAG-path parsing, and scene-index traversal.
test/lib/mayaUsd/render/mayaToHydra/cpp/testUtils.cpp	Implements new helpers; improves text comparison normalization and exposes dump output path helper.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMeshPrimvars.py	New Python harness to build a mesh scene and run new C++ primvar/dirtying tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMeshPrimvars.cpp	New mesh primvar dirtying + param-attr list consistency tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMayaNodesAttributesDirtying.py	Renames/expands dirtying tests for mesh/camera/light/material and light params.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMayaNodesAttributesDirtying.cpp	New, more detailed dirty-notice validation for extension attrs and light params.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMayaNodesAttributes.py	Renames test class; adds scene setup including an Arnold light; adds new C++ test entrypoints.
test/lib/mayaUsd/render/mayaToHydra/cpp/testLightPrimvars.py	New Python harness for Arnold light primvar translation + dirtying tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testLightPrimvars.cpp	New C++ tests for light primvar translation/dirtying and param-attr list consistency.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCustomAttributes.cpp	Reworks tests to validate “default values don’t emit primvars” and primvar removal on reset; adds camera compound test and cross-node reset test.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCustomAttributeTypes.cpp	Switches to shared `CreatePrimPredicate`; updates comment for renamed Python test.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCameraPrimvars.py	New Python harness for camera primvar dirtying + param-attr list consistency tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCameraPrimvars.cpp	New camera primvar dirtying + param-attr list consistency tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCamera.cpp	Uses shared `CreatePrimPredicate`.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCustomAttributeDirtying.cpp	Removes old dirtying test file (replaced by new suites).
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/*	Adds golden reference outputs + README for primvar serialization comparisons.
test/lib/mayaUsd/render/mayaToHydra/cpp/CMakeLists.txt	Registers new C++ test sources (mesh/camera/light/dirtying).
test/lib/mayaUsd/render/mayaToHydra/CMakeLists.txt	Registers new interactive Python tests; updates renamed scripts; adds mesh-adapter test script.
lib/mayaHydra/hydraExtensions/mixedUtils.h	Renames and extends attribute extraction API to support “include all (non-builtin) attrs” option.
lib/mayaHydra/hydraExtensions/mixedUtils.cpp	Implements expanded attribute collection and default filtering (incl. plugin default workarounds).
lib/mayaHydra/hydraExtensions/adapters/renderItemAdapter.cpp	Adjusts attribute-changed callback to avoid duplicates for camera/light render items and to gate on `kAttributeSet`.
lib/mayaHydra/hydraExtensions/adapters/nurbsCurveAdapter.cpp	Routes attribute changes through the new primvar-dirty helper.
lib/mayaHydra/hydraExtensions/adapters/meshAdapterTestUtils.h	New test-only API to expose mesh param attribute list.
lib/mayaHydra/hydraExtensions/adapters/meshAdapter.cpp	Adds mesh param attribute list, improves dirty callback handling for compound attrs, and updates primvar dirtying behavior.
lib/mayaHydra/hydraExtensions/adapters/lightAdapter.h	Adds primvar inclusion override + param-attr test API + primvar dirtying hooks.
lib/mayaHydra/hydraExtensions/adapters/lightAdapter.cpp	Refactors callbacks to reduce redundant notifications and to distinguish param vs primvar-only attrs.
lib/mayaHydra/hydraExtensions/adapters/cameraAdapter.h	Adds param-attr test API and primvar dirtying hook.
lib/mayaHydra/hydraExtensions/adapters/cameraAdapter.cpp	Refactors callbacks to combine param+primvar dirtying and handle reset-to-default updates.
lib/mayaHydra/hydraExtensions/adapters/adapter.h	Introduces shared primvar-dirty helpers and param-attribute set utilities.
lib/mayaHydra/hydraExtensions/adapters/adapter.cpp	Implements shared helpers, integrates new attribute extraction, and consolidates dirty-bit emission.
lib/mayaHydra/hydraExtensions/adapters/CMakeLists.txt	Adds new mesh adapter test utils header to build.

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lib/mayaHydra/hydraExtensions/mixedUtils.cpp

        MObject      attrObj = nodeFn.attribute(i);
        MFnAttribute attrFn(attrObj);
        auto         attrName = attrFn.name().asChar();
-        MPlug        attrPlug(node, attrObj);
+        MStatus      plugStatus;
+        MPlug        attrPlug = FindPlugWithFallback(nodeFn, attrFn.name(), plugStatus);
+        if (!plugStatus || attrPlug.isNull())


lib/mayaHydra/hydraExtensions/adapters/adapter.h

+        static std::unordered_set<std::string> s;
+        static bool init = false;
+        if (!init) {
+            for (const char* name : names) {
+                s.insert(name);
+            }
+            init = true;
+        }


test/lib/mayaUsd/render/mayaToHydra/cpp/testCustomAttributes.cpp

+        const MString cmd = "setAttr -type \"" + typeName + "\" \"" + attrName + "\" 0 0 0";
+        ASSERT_EQ(MGlobal::executeCommand(cmd), MStatus::kSuccess);
+
+        const double x = elementPlug.child(0).asDouble();
+        const double y = elementPlug.child(1).asDouble();
+        const double z = elementPlug.child(2).asDouble();
+        if (std::abs(x) > 1e-9 || std::abs(y) > 1e-9 || std::abs(z) > 1e-9) {


Copilot

Pull request overview

This PR extends Maya→Hydra primvar translation/dirtying to better support mesh, camera, and light attributes (including plugin attributes like Arnold ai*), and adds/updates a substantial set of C++/Python tests plus golden reference outputs.

Changes:

Refactors attribute collection for primvar translation (new GetAttributesFromNode + default-value skipping).
Reworks adapter dirtying behavior for cameras/lights/meshes to reduce duplicate notifications and ensure primvars update/removal on reset-to-default.
Adds new primvar/dirtying C++ tests with Python scene setup and golden reference outputs; updates test utilities to support these patterns.

Reviewed changes

Copilot reviewed 38 out of 39 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
test/lib/mayaUsd/render/mayaToHydra/cpp/testUtils.h	Adds reusable prim-finding helpers and path/optionVar utilities for new tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testUtils.cpp	Implements new test helpers; normalizes output/reference comparison behavior.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMeshPrimvars.py	New Python harness to build a mesh scene for C++ primvar/dirtying tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMeshPrimvars.cpp	New C++ tests for mesh primvar dirtying and param-attr list consistency.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMayaNodesAttributesDirtying.py	Renames/expands test script and routes to new C++ test suite.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMayaNodesAttributesDirtying.cpp	New C++ dirtying tests for mesh/camera/light/material attributes.
test/lib/mayaUsd/render/mayaToHydra/cpp/testMayaNodesAttributes.py	Renames test class and adds a scene variant including an Arnold light.
test/lib/mayaUsd/render/mayaToHydra/cpp/testLightPrimvars.py	New Python harness to build an Arnold light scene for C++ tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testLightPrimvars.cpp	New C++ tests for light primvar translation/dirtying and param-attr list consistency.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCameraPrimvars.py	New Python harness to build a camera scene for C++ tests.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCameraPrimvars.cpp	New C++ tests for camera primvar dirtying and param-attr list consistency.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCustomAttributes.cpp	Updates/extends custom-attribute tests (default suppression + reset behavior).
test/lib/mayaUsd/render/mayaToHydra/cpp/testCustomAttributeTypes.cpp	Switches to shared prim predicate; updates test reference to renamed Python file.
test/lib/mayaUsd/render/mayaToHydra/cpp/testCamera.cpp	Uses shared `CreatePrimPredicate` helper.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/light_primvar_aiColorTemperature_modified.txt	New golden output for light primvar test.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/cube_primvar_aiSubdivIterations_modified.txt	New golden output for mesh primvar test.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/cube_primvar_aiSubdivIterations_fresh.txt	Updates golden output formatting/whitespace.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/cube_primvar_aiAutobumpVisibility_modified.txt	New golden output for mesh primvar test.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/cube_primvar_aiAutobumpVisibility_fresh.txt	Updates golden output formatting/whitespace.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/cube_primvar_absent.txt	New golden output representing “primvar absent”.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/camera_primvar_aiUScale_modified.txt	New golden output for camera primvar test.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/camera_primvar_aiLookAt_modified.txt	New golden output for camera compound primvar test.
test/lib/mayaUsd/render/mayaToHydra/cpp/MayaNodesAttributesTest/README.md	Documents golden-file usage and comparison behavior.
test/lib/mayaUsd/render/mayaToHydra/cpp/CMakeLists.txt	Adds new C++ test sources; replaces removed dirtying test file.
test/lib/mayaUsd/render/mayaToHydra/CMakeLists.txt	Registers new interactive Python test scripts and mesh-adapter test list updates.
lib/mayaHydra/hydraExtensions/mixedUtils.h	Renames/extends exported attribute-gathering API for primvar translation.
lib/mayaHydra/hydraExtensions/mixedUtils.cpp	Implements expanded attribute gathering with default suppression and skip list.
lib/mayaHydra/hydraExtensions/adapters/renderItemAdapter.cpp	Adjusts attribute-change callback logic for primvar dirtying (skip cameras/lights).
lib/mayaHydra/hydraExtensions/adapters/nurbsCurveAdapter.cpp	Switches to new primvar-dirty helper path.
lib/mayaHydra/hydraExtensions/adapters/meshAdapterTestUtils.h	New exported helper for mesh adapter param-attribute list unit testing.
lib/mayaHydra/hydraExtensions/adapters/meshAdapter.cpp	Adds param-attr list exposure + adjusts dirtying logic to reduce duplicates.
lib/mayaHydra/hydraExtensions/adapters/lightAdapter.h	Adds primvar/param dirtying overrides and test-only param-attr accessor.
lib/mayaHydra/hydraExtensions/adapters/lightAdapter.cpp	Refactors dirtying logic and centralizes light param attribute list.
lib/mayaHydra/hydraExtensions/adapters/cameraAdapter.h	Adds primvar dirty gating + test-only param-attr accessor.
lib/mayaHydra/hydraExtensions/adapters/cameraAdapter.cpp	Refactors dirtying callbacks to reduce duplicates and ensure primvar updates on reset.
lib/mayaHydra/hydraExtensions/adapters/adapter.h	Adds new primvar-dirty helpers and attribute-set utilities for adapters.
lib/mayaHydra/hydraExtensions/adapters/adapter.cpp	Switches to new attribute gathering + consolidated dirtying for primvar changes.
lib/mayaHydra/hydraExtensions/adapters/CMakeLists.txt	Registers new mesh adapter test utils header in build.

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lib/mayaHydra/hydraExtensions/mixedUtils.cpp

+// Populate a dictionary with attribute values for translation to Hydra primvars.
+// When includeAllAttributes is false: only extension and dynamic attributes.
+// When true: all non-builtin attributes (skip default values in both cases).
+void GetAttributesFromNode(
+    const MObject& node, PXR_NS::VtDictionary& attrs, bool includeAllAttributes)
 {
+    attrs.clear();
    MStatus           status;
    MFnDependencyNode nodeFn(node, &status);
    if (ARCH_UNLIKELY(!status)) {
        return;
    }

+    const auto& builtInSkipSet = _GetBuiltInAttributeSkipSet();
+
    for (size_t i = 0; i < nodeFn.attributeCount(); i++) {
        MObject      attrObj = nodeFn.attribute(i);
        MFnAttribute attrFn(attrObj);
-        auto         attrName = attrFn.name().asChar();
-        MPlug        attrPlug(node, attrObj);
+        const MString attrNameStr = attrFn.name();
+        const char*   attrName = attrNameStr.asChar();
+        MStatus       plugStatus;
+        MPlug         attrPlug = FindPlugWithFallback(nodeFn, attrNameStr, plugStatus);
+        if (!plugStatus || attrPlug.isNull())
+            continue;
        if (attrPlug.isChild())
            continue;

-        if (attrFn.isExtension() || attrFn.isDynamic()) {
-            const bool ignoreDefault = attrFn.isDynamic();
-            switch (attrObj.apiType()) {
+        const bool isExtOrDynamic = attrFn.isExtension() || attrFn.isDynamic();
+        if (!includeAllAttributes && !isExtOrDynamic)
+            continue;
+        if (includeAllAttributes && builtInSkipSet.count(attrName) > 0)
+            continue;
+


lib/mayaHydra/hydraExtensions/adapters/lightAdapter.h

    TfToken GetRenderTag() const override;

+    MAYAHYDRALIB_API
+    bool IncludeAllAttributesInPrimvars() const override { return true; }
+
+    bool ShouldMarkPrimvarDirtyForAttributeChange(const MPlug& plug) const override;
+    HdDirtyBits GetExtraDirtyBitsForPrimvarAttributeChange(const MPlug& plug) const override;


lib/mayaHydra/hydraExtensions/adapters/adapter.h

+    /// Skips child plugs to avoid duplicate notifications for compound attrs (e.g. color.r).
+    /// Override ShouldMarkPrimvarDirtyForAttributeChange to return false when another callback
+    /// already marks DirtyPrimvar (e.g. mesh _dirtyBits, light param attr list).


test/lib/mayaUsd/render/mayaToHydra/cpp/testMayaNodesAttributesDirtying.cpp

+    const SceneIndicesVector& sceneIndices = GetTerminalSceneIndices();
+    ASSERT_GT(sceneIndices.size(), 0u);
+    SceneIndexNotificationsAccumulator notifsAccumulator(sceneIndices.front());
+
+    auto checkDirty = [&](const std::string& nodeName, double value) {
+        const size_t startIndex = notifsAccumulator.GetDirtiedPrimEntries().size();
+        SetAttrAndRefresh(nodeName, value);
+        EXPECT_TRUE(FindDirtyPrimWithPrimvarValueSince(notifsAccumulator, startIndex, value));
+    };


lib/mayaHydra/hydraExtensions/mixedUtils.h

+ * @brief Get attributes from a Maya node for translation to Hydra primvars.
 *
- * This function retrieves all the extension and dynamic attributes of a given Maya node and stores
- * them in a map. The keys of the map are the attribute names, and the values are the attribute values.
+ * When includeAllAttributes is false, only extension and dynamic attributes are retrieved. When true, all non-builtin
+ * attributes are retrieved (e.g. for lights to translate plugin attributes like Arnold ai*).
 *
 * @param[in] node is the node in the Maya scene graph.
 * @param[out] attrs is a map that will contain the attribute names and their corresponding values.
+ * @param[in] includeAllAttributes when true, process all non-builtin attributes; when false, only
+ *            extension and dynamic attributes.
 */
 MAYAHYDRALIB_API
-void GetExtensionAndDynamicAttributesFromNode(
+void GetAttributesFromNode(
    const MObject& node,
-    PXR_NS::VtDictionary& attrs);
+    PXR_NS::VtDictionary& attrs,
+    bool includeAllAttributes = false);


ppt-adsk

Did not look at the tests, but we can start with this.

test/lib/mayaUsd/render/mayaToHydra/cpp/testUtils.cpp

lib/mayaHydra/hydraExtensions/adapters/adapter.h

lib/mayaHydra/hydraExtensions/adapters/adapter.cpp

lib/mayaHydra/hydraExtensions/adapters/cameraAdapter.cpp

lib/mayaHydra/hydraExtensions/mixedUtils.h

lib/mayaHydra/hydraExtensions/adapters/adapter.h

ppt-adsk

Just a couple more questions.

test/lib/mayaUsd/render/mayaToHydra/cpp/testUtils.cpp

ppt-adsk · 2026-03-18T18:34:08Z

lib/mayaHydra/hydraExtensions/adapters/meshAdapterTestUtils.h

+#include <string>
+#include <unordered_set>
+
+PXR_NAMESPACE_OPEN_SCOPE


Sorry for the late catch. Why is this in the PXR namespace?

It's a mistake, I moved it to the maya hydra namespace. Thanks for catching this !

ppt-adsk · 2026-03-18T18:34:52Z

lib/mayaHydra/hydraExtensions/mixedUtils.cpp

+    const VtValue& /* defaultVal */,
+    const bool /* hasDefault */,


If we don't need these any more, shouldn't we just remove them?

You're right, some leftovers of iterations

ppt-adsk

Nit-pick, if you could fix would be nice.

test/lib/mayaUsd/render/mayaToHydra/cpp/testMeshPrimvars.cpp

HYDRA-1760 : Support translation of maya attributes to hydra for ligh…

8386c86

…ts, cameras and meshes

lanierd-adsk commented Mar 16, 2026

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Self code review, refactor code and add more comments.

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lanierd-adsk assigned lanierd-adsk and unassigned lanierd-adsk Mar 16, 2026

lanierd-adsk changed the title ~~HYDRA-1760 : Support translation of maya attributes to hydra for ligh…~~ HYDRA-1760 : Support translation of maya attributes to hydra for lights, cameras and meshes Mar 16, 2026

lanierd-adsk requested review from ppt-adsk March 16, 2026 16:26

lanierd-adsk changed the title ~~HYDRA-1760 : Support translation of maya attributes to hydra for lights, cameras and meshes~~ HYDRA-1760 : Support translation of maya extension attributes to hydra for lights, cameras and meshes Mar 16, 2026

Missing one file

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test/lib/mayaUsd/render/mayaToHydra/cpp/testMeshPrimvars.cpp Outdated Show resolved Hide resolved

Minor fix

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lanierd-adsk assigned lanierd-adsk and unassigned lanierd-adsk Mar 19, 2026

lanierd-adsk requested a review from ppt-adsk March 19, 2026 16:45

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		const VtValue& /* defaultVal */,
		const bool /* hasDefault */,

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lanierd-adsk commented Mar 16, 2026 •

edited

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