use SdfPathVector for aov_shaders (#1322)

* use SdfPathVector for aov_shaders

* read multiple aov_shaders in the procedural + test

* handle conversion from VtValue to SdfPathVector

common/common_utils.h

@@ -56,6 +56,23 @@ void ArnoldUsdCheckForSdfPathValue(const VtValue& value, F&& f)
     }
 }
 
+template <typename F>
+ARCH_HIDDEN
+void ArnoldUsdCheckForSdfPathVectorValue(const VtValue& value, F&& f)
+{
+    if (value.IsHolding<SdfPathVector>()) {
+       f(value.UncheckedGet<SdfPathVector>());
+    } else if (value.IsHolding<std::string>()) {
+        // Split with space
+        const auto s = value.UncheckedGet<std::string>();
+        SdfPathVector paths;
+        for (const auto &path: TfStringTokenize(s)) {
+            paths.emplace_back(path);
+        }
+        f(paths);
+    }
+}
+
 ARCH_HIDDEN
 int ArnoldUsdGetLogVerbosityFromFlags(int flags);
 

render_delegate/render_delegate.cpp

@@ -622,7 +622,7 @@ void HdArnoldRenderDelegate::_SetRenderSetting(const TfToken& _key, const VtValu
     } else if (key == str::t_atmosphere) {
         ArnoldUsdCheckForSdfPathValue(value, [&](const SdfPath& p) { _atmosphere = p; });
     } else if (key == str::t_aov_shaders) {
-        ArnoldUsdCheckForSdfPathValue(value, [&](const SdfPath& p) { _aov_shaders = p; });
+        ArnoldUsdCheckForSdfPathVectorValue(value, [&](const SdfPathVector& p) { _aov_shaders = p; });
     } else if (key == str::t_imager) {
         ArnoldUsdCheckForSdfPathValue(value, [&](const SdfPath& p) { _imager = p; });
     } else if (key == str::t_subdiv_dicing_camera) {
@@ -817,7 +817,10 @@ VtValue HdArnoldRenderDelegate::GetRenderSetting(const TfToken& _key) const
     } else if (key == str::t_atmosphere) {
         return VtValue(_atmosphere.GetString());
     } else if (key == str::t_aov_shaders) {
-        return VtValue(_aov_shaders.GetString());
+        // There should be a function in common_utils.cpp
+        std::vector<std::string> pathsAsString;
+        std::transform(_aov_shaders.begin(), _aov_shaders.end(), std::back_inserter(pathsAsString), [](const auto &p){return p.GetString();});
+        return VtValue(TfStringJoin(pathsAsString));
     } else if (key == str::t_imager) {
         return VtValue(_imager.GetString());
     }  else if (key == str::t_subdiv_dicing_camera) {
@@ -1460,10 +1463,15 @@ AtNode* HdArnoldRenderDelegate::GetAtmosphere(HdRenderIndex* renderIndex)
 
 std::vector<AtNode*> HdArnoldRenderDelegate::GetAovShaders(HdRenderIndex* renderIndex)
 {
-    const HdArnoldNodeGraph *nodeGraph = HdArnoldNodeGraph::GetNodeGraph(renderIndex, _aov_shaders);
-    if (nodeGraph)
-        return nodeGraph->GetTerminals(_tokens->aovShadersArray);
-    return std::vector<AtNode *>();
+    std::vector<AtNode *> nodes;
+    for (const auto &materialPath: _aov_shaders) {
+        const HdArnoldNodeGraph *nodeGraph = HdArnoldNodeGraph::GetNodeGraph(renderIndex, materialPath);
+        if (nodeGraph) {
+            const auto &terminals = nodeGraph->GetTerminals(_tokens->aovShadersArray);
+            std::copy(terminals.begin(), terminals.end(), std::back_inserter(nodes));
+        }
+    }
+    return nodes;
 }
 
 AtNode* HdArnoldRenderDelegate::GetImager(HdRenderIndex* renderIndex)

render_delegate/render_delegate.h

@@ -561,7 +561,7 @@ class HdArnoldRenderDelegate final : public HdRenderDelegate {
     SdfPath _id;           ///< Path of the Render Delegate.
     SdfPath _background;   ///< Path to the background shader.
     SdfPath _atmosphere;   ///< Path to the atmosphere shader.
-    SdfPath _aov_shaders;  ///< Path to the aov shaders.
+    SdfPathVector _aov_shaders;  ///< Path to the aov shaders.
     SdfPath _imager;      ///< Path to the root imager node.
     SdfPath _subdiv_dicing_camera;  ///< Path to the subdiv dicing camera
     AtUniverse* _universe; ///< Universe used by the Render Delegate.

testsuite/test_1321/README

@@ -0,0 +1,7 @@
+Allow list of AOV ArnoldNodeGraph primitives in RenderSettings
+
+See #1321
+
+author: cyril.pichard 
+
+PARAMS: {'scene':'test.usda', 'output_image': 'testrender.exr', 'reference_image':'ref/reference.exr' }

translator/reader/read_options.cpp

@@ -20,6 +20,7 @@
 #include <vector>
 
 #include <pxr/base/tf/pathUtils.h>
+#include <pxr/base/tf/stringUtils.h>
 #include <pxr/usd/usdRender/product.h>
 #include <pxr/usd/usdRender/settings.h>
 #include <pxr/usd/usdRender/var.h>
@@ -160,36 +161,37 @@ static inline void UsdArnoldNodeGraphAovConnection(AtNode *options, const UsdPri
     const TimeSettings &time = context.GetTimeSettings();
     VtValue value;
     if (attr && attr.Get(&value, time.frame)) {
-        // RenderSettings have a string attribute, referencing a prim in the stage
+        // RenderSettings have a string attribute, referencing multiple prims in the stage
         std::string valStr = VtValueGetString(value, &attr);
         if (!valStr.empty()) {
-            SdfPath path(valStr);
-            // We check if there is a primitive at the path of this string
-            UsdPrim ngPrim = context.GetReader()->GetStage()->GetPrimAtPath(SdfPath(valStr));
-            // We verify if the primitive is indeed a ArnoldNodeGraph
-            if (ngPrim && ngPrim.GetTypeName() == _tokens->ArnoldNodeGraph) {
-                AtArray* array = AiNodeGetArray(options, str::aov_shaders);
-                unsigned numElements = AiArrayGetNumElements(array);
-                // We can use a UsdShadeShader schema in order to read connections
-                UsdShadeShader ngShader(ngPrim);
-                for (unsigned i=1;; i++) {
-                    // the output terminal name will be aov_shader:i{1,...,n} as a contiguous array
-                    TfToken outputName(attrBase + std::string(":i") + std::to_string(i));
-                    UsdShadeOutput outputAttr = ngShader.GetOutput(outputName);
-                    if (!outputAttr)
-                        break;
-                    SdfPathVector sourcePaths;
-                    // Check which shader is connected to this output
-                    if (outputAttr.HasConnectedSource() && outputAttr.GetRawConnectedSourcePaths(&sourcePaths) &&
-                        !sourcePaths.empty()) {
-                        SdfPath outPath(sourcePaths[0].GetPrimPath());
-                        UsdPrim outPrim = context.GetReader()->GetStage()->GetPrimAtPath(outPath);
-                        if (outPrim) {
-                            // we connect to aov_shaders{0,...,n-1} parameters i.e. 0 indexed, offset from any previous connections
-                            unsigned index = numElements + i-1;
-                            std::string outputElement = attrBase + "[" + std::to_string(index) + "]";
-                            context.AddConnection(options, outputElement, outPath.GetText(),
-                                                  UsdArnoldReader::CONNECTION_PTR);
+            AtArray* aovShadersArray = AiNodeGetArray(options, str::aov_shaders);
+            unsigned numElements = AiArrayGetNumElements(aovShadersArray);
+            for(const auto &nodeGraphPrimName: TfStringTokenize(valStr)) {
+                SdfPath nodeGraphPrimPath(nodeGraphPrimName);
+                // We check if there is a primitive at the path of this string
+                UsdPrim nodeGraphPrim = context.GetReader()->GetStage()->GetPrimAtPath(nodeGraphPrimPath);
+                if (nodeGraphPrim && nodeGraphPrim.GetTypeName() == _tokens->ArnoldNodeGraph) {
+                    // We can use a UsdShadeShader schema in order to read connections
+                    UsdShadeShader ngShader(nodeGraphPrim);
+                    for (unsigned aovShaderIndex=1;; aovShaderIndex++) {
+                        // the output terminal name will be aov_shader:i{1,...,n} as a contiguous array
+                        TfToken outputName(attrBase + std::string(":i") + std::to_string(aovShaderIndex));
+                        UsdShadeOutput outputAttr = ngShader.GetOutput(outputName);
+                        if (!outputAttr) {
+                            break;
+                        }
+                        SdfPathVector sourcePaths;
+                        // Check which shader is connected to this output
+                        if (outputAttr.HasConnectedSource() && outputAttr.GetRawConnectedSourcePaths(&sourcePaths)) {
+                            for(const SdfPath &aovShaderPath : sourcePaths) {
+                                SdfPath aovShaderPrimPath(aovShaderPath.GetPrimPath());
+                                UsdPrim outPrim = context.GetReader()->GetStage()->GetPrimAtPath(aovShaderPrimPath);
+                                if (outPrim) {
+                                    // we connect to aov_shaders{0,...,n-1} parameters i.e. 0 indexed, offset from any previous connections
+                                    std::string optionAovShaderElement = attrBase + "[" + std::to_string(numElements++) + "]";
+                                    context.AddConnection(options, optionAovShaderElement, aovShaderPrimPath.GetText(), UsdArnoldReader::CONNECTION_PTR);
+                                }
+                            }
                         }
                     }
                 }