HYDRA-2414 : Fix external camera resolution for two-segment UFE paths (#474)

Author: benyoon-adsk

lib/mayaHydra/hydraExtensions/sceneIndex/mhExternalCameraOverrideSceneIndex.cpp

@@ -38,17 +38,35 @@ const TfToken kExternalCameraToken("adskUsd:externalCamera");
 // ExternalCameraResolvingSceneIndex.
 const SdfPath kExternalCameraPrefix("/__adskUsd__externalCamera");
 
+// Sentinel SdfPath component used to preserve UFE multi-segment paths (Maya
+// DAG path ',' USD path) when storing external camera paths in Hydra.
+const std::string kUfeSegmentSentinel("__ufeSegment__");
+
 // External camera paths are either through USD (already uses '/' as a
 // separator), or through Maya (uses '|' as a separator, converted to '/' for
-// SdfPath representation).  We also erase the UFE path segment ',' separator.
-SdfPath SanitizeExternalPath(const std::string& rawValue)
+// SdfPath representation).  We also replace the UFE path segment ',' separator with
+// kUfeSegmentSentinel followed by UFE runTimeId.
+// ex: |stage1|stageShape1,/camera1
+//  -> /__adskUsd__externalCamera/stage1/stageShape1__ufeSegment__/camera1
+// Note: For now, we assume the second segment is a USD path.
+// This may not always be the case, the second segment could be a path from a custom plugin.
+// Need to handle this case in the future.
+SdfPath SanitizeExternalPath(const std::string& ufePathStr)
 {
-    std::string pathStr = rawValue;
+    const auto segmentEnd = ufePathStr.find(',');
 
+    // Maya path: replace '|' with '/'
+    auto pathStr = ufePathStr.substr(0, segmentEnd);
     std::replace(pathStr.begin(), pathStr.end(), '|', '/');
-    pathStr.erase(std::remove(pathStr.begin(), pathStr.end(), ','), pathStr.end());
 
-    return kExternalCameraPrefix.AppendPath(SdfPath(pathStr).MakeRelativePath(SdfPath::AbsoluteRootPath()));
+    if (segmentEnd != std::string::npos) {
+        // Assume the second segment is a USD path, and already has '/' path
+        // component separator.  Append segment separator sentinel and USD path.
+        pathStr += kUfeSegmentSentinel + ufePathStr.substr(segmentEnd + 1);
+    }
+
+    return kExternalCameraPrefix.AppendPath(
+        SdfPath(pathStr).MakeRelativePath(SdfPath::AbsoluteRootPath()));
 }
 
 } // anonymous namespace

lib/mayaHydra/hydraExtensions/sceneIndex/mhExternalCameraOverrideSceneIndex.h

@@ -39,8 +39,8 @@ typedef PXR_NS::TfRefPtr<const MhExternalCameraOverrideSceneIndex>
 /// A filtering scene index that overrides the camera data source on
 /// renderSettings and renderProduct prims when an adskUsd:externalCamera key
 /// is present in their namespacedSettings.  The external camera path is
-/// sanitized ('|' -> '/', ',' stripped) and prefixed with
-/// "/__adskUsd__externalCamera" before being written into the camera field.
+/// sanitized ('|' -> '/', ',' replaced with __ufeSegment__) and prefixed
+/// with "/__adskUsd__externalCamera" before being written into the camera field.
 ///
 class MhExternalCameraOverrideSceneIndex
     : public PXR_NS::HdSingleInputFilteringSceneIndexBase

lib/mayaHydra/hydraExtensions/sceneIndex/mhExternalCameraResolvingSceneIndex.cpp

@@ -28,14 +28,15 @@
 #include <pxr/imaging/hd/tokens.h>
 #include <pxr/usd/sdf/path.h>
 
-#include <ufe/path.h>
+#include <ufe/pathString.h>
 
 PXR_NAMESPACE_USING_DIRECTIVE
 using namespace UfeExtensions;
 
 namespace {
 
 const TfToken kExternalCameraComponent("__adskUsd__externalCamera");
+const std::string kUfeSegmentSentinel("__ufeSegment__");
 
 SdfPath ResolveExternalCameraPath(const SdfPath& inputPath)
 {
@@ -91,12 +92,19 @@ SdfPath ResolveExternalCameraPath(const SdfPath& inputPath)
     // multiple reader behavior), which has been considered in the past, but
     // this requires UFE versus Maya TBB configuration management.
 
-    Ufe::PathSegment::Components components;
-    components.push_back(Ufe::PathComponent("world"));
-    for (const SdfPath& prefix : appPath.GetPrefixes()) {
-        components.push_back(prefix.GetNameToken().GetString());
+    const auto appPathStr = appPath.GetString();
+    const auto segmentEnd = appPathStr.find(kUfeSegmentSentinel);
+
+    // Maya path: replace '/' with '|'
+    auto pathStr = appPathStr.substr(0, segmentEnd);
+    std::replace(pathStr.begin(), pathStr.end(), '/', '|');
+
+    if (segmentEnd != std::string::npos) {
+        // Assume the second segment is a USD path, and already has '/' path
+        // component separator.  Remove segment separator sentinel.
+        pathStr += "," + appPathStr.substr(segmentEnd + kUfeSegmentSentinel.length());
     }
-    Ufe::Path appUfePath(Ufe::PathSegment(components, getMayaRunTimeId(), '|'));
+    auto appUfePath = Ufe::PathString::path(pathStr);
     auto hydraPath = Fvp::ufePathToPrimSelections(appUfePath);
 
     // Camera is non-instanced, so there will be a single PrimSelection.

test/lib/cmdLineRender/CMakeLists.txt

@@ -117,6 +117,7 @@ mayaHydra_add_cmd_line_render_test(${scene}
     RENDERED_IMAGE_SUBDIR projects/default/images
     RENDERED_IMAGE_NAME ${sceneFileNameNoExt}
     RENDERER HdStormRendererPlugin
+    TEST_NAME_SUFFIX Storm
     RENDERER_ARGS "-x 960 -y 540 -cam \"|camera1\" -rd ../images -im ${sceneFileNameNoExt}"
 )
 
@@ -129,9 +130,39 @@ mayaHydra_add_cmd_line_render_test(${scene}
     RENDERED_IMAGE_SUBDIR projects/default/images
     RENDERED_IMAGE_NAME ${sceneFileNameNoExt}
     RENDERER HdStormRendererPlugin
+    TEST_NAME_SUFFIX Storm
     RENDERER_ARGS "-x 960 -y 540 -cam \"|stage1|stageShape1,/camera1\" -rd ../images -im ${sceneFileNameNoExt}"
 )
 
+# Test -cam with USD camera in HdArnold.
+set(scene basic/usdCamera.ma)
+cmake_path(GET scene STEM sceneFileNameNoExt)
+mayaHydra_add_cmd_line_render_test(${scene}
+    COPY_SCENE
+    RENDERED_IMAGE_SUBDIR projects/default/images
+    RENDERED_IMAGE_NAME ${sceneFileNameNoExt}
+    RENDERER HdArnoldRendererPlugin
+    TEST_NAME_SUFFIX Arnold
+    RENDERER_ARGS "-x 960 -y 540 -cam \"|stage1|stageShape1,/camera1\" -rd ../images -im ${sceneFileNameNoExt}"
+)
+
+# Test the same as above but with Hydra V2 render settings.
+set(scene basic/usdCamera.ma)
+set(render_dir ${CMAKE_BINARY_DIR}/test/Temporary/${sceneFileNameNoExt}_Arnold_v2_rs/projects/default/images)
+cmake_path(GET scene STEM sceneFileNameNoExt)
+mayaHydra_add_cmd_line_render_test(${scene}
+    COPY_SCENE
+    RENDERER HdArnoldRendererPlugin
+    RENDERED_IMAGE_SUBDIR projects/default/images
+    RENDERED_IMAGE_NAME ${sceneFileNameNoExt}_Arnold_v2_rs
+    RENDERER_ARGS "-x 960 -y 540 -cam \"|stage1|stageShape1,/camera1\" -rd \"${render_dir}\" -im ${sceneFileNameNoExt}_Arnold_v2_rs"
+    TEST_NAME_SUFFIX Arnold_v2_rs
+    ENV
+        "MAYA_HYDRA_HD_ARNOLD_HYDRA_V2_RENDER_SETTINGS=1"
+        "USDIMAGINGGL_ENGINE_ENABLE_SCENE_INDEX=1"
+        "TF_DEBUG=MAYAHYDRAPLUGIN_BATCHRENDER_RENDER_SETTINGS"
+)
+
 # Use a small vertical resolution to avoid the Arnold watermark.
 mayaHydra_add_cmd_line_render_test(renderSettings/arnoldResolution.ma
     COPY_SCENE