[hdEmbree] add direct camera visibility support for rect lights (hdEmbree-UsdLux-PR12)

build_scripts/build_usd.py

@@ -2610,6 +2610,7 @@ def _JoinVersion(v):
       OpenVDB support:          {enableOpenVDB}
       OpenImageIO support:      {buildOIIO} 
       OpenColorIO support:      {buildOCIO} 
+      Embree support:           {buildEmbree}
       PRMan support:            {buildPrman}
     UsdImaging                  {buildUsdImaging}
       usdview:                  {buildUsdview}
@@ -2673,6 +2674,7 @@ def FormatBuildArguments(buildArgs):
     enableOpenVDB=("On" if context.enableOpenVDB else "Off"),
     buildOIIO=("On" if context.buildOIIO else "Off"),
     buildOCIO=("On" if context.buildOCIO else "Off"),
+    buildEmbree=("On" if context.buildEmbree else "Off"),
     buildPrman=("On" if context.buildPrman else "Off"),
     buildUsdImaging=("On" if context.buildUsdImaging else "Off"),
     buildUsdview=("On" if context.buildUsdview else "Off"),

pxr/base/work/threadLimits.cpp

@@ -71,14 +71,14 @@ WorkGetPhysicalConcurrencyLimit()
 #endif
 }
 
-// This function always returns an actual thread count >= 1.
+// This function always returns either 0 (meaning "no change") or >= 1
 static unsigned
 Work_NormalizeThreadCount(const int n)
 {
     // Zero means "no change", and n >= 1 means exactly n threads, so simply
     // pass those values through unchanged.
     // For negative integers, subtract the absolute value from the total number
-    // of available cores (denoting all but n cores). If n == number of cores,
+    // of available cores (denoting all but n cores). If |n| >= number of cores,
     // clamp to 1 to set single-threaded mode.
     return n >= 0 ? n : std::max<int>(1, n + WorkGetPhysicalConcurrencyLimit());
 }

pxr/imaging/plugin/hdEmbree/CMakeLists.txt

@@ -31,6 +31,7 @@ pxr_plugin(hdEmbree
     PUBLIC_CLASSES
         config
         instancer
+        light
         mesh
         meshSamplers
         renderBuffer
@@ -45,6 +46,7 @@ pxr_plugin(hdEmbree
         renderParam.h
 
     PRIVATE_CLASSES
+        debugCodes
         implicitSurfaceSceneIndexPlugin
 
     RESOURCE_FILES

pxr/imaging/plugin/hdEmbree/context.h

@@ -13,12 +13,14 @@
 
 #include "pxr/base/gf/matrix4f.h"
 #include "pxr/base/vt/array.h"
+#include "pxr/base/vt/types.h"
 
 #include <embree3/rtcore.h>
 
 PXR_NAMESPACE_OPEN_SCOPE
 
 class HdRprim;
+class HdEmbree_Light;
 
 /// \class HdEmbreePrototypeContext
 ///
@@ -51,6 +53,8 @@ struct HdEmbreeInstanceContext
     RTCScene rootScene;
     /// The instance id of this instance.
     int32_t instanceId;
+    /// The light (if this is a light)
+    HdEmbree_Light *light = nullptr;
 };
 
 

pxr/imaging/plugin/hdEmbree/debugCodes.cpp

@@ -0,0 +1,20 @@
+//
+// Copyright 2024 Pixar
+//
+// Licensed under the terms set forth in the LICENSE.txt file available at
+// https://openusd.org/license.
+//
+#include "pxr/pxr.h"
+#include "pxr/imaging/plugin/hdEmbree/debugCodes.h"
+
+#include "pxr/base/tf/debug.h"
+#include "pxr/base/tf/registryManager.h"
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+TF_REGISTRY_FUNCTION(TfDebug)
+{
+    TF_DEBUG_ENVIRONMENT_SYMBOL(HDEMBREE_LIGHT_CREATE, "Creation of HdEmbree lights");
+}
+
+PXR_NAMESPACE_CLOSE_SCOPE

pxr/imaging/plugin/hdEmbree/debugCodes.h

@@ -0,0 +1,21 @@
+//
+// Copyright 2024 Pixar
+//
+// Licensed under the terms set forth in the LICENSE.txt file available at
+// https://openusd.org/license.
+//
+#ifndef PXR_IMAGING_PLUGIN_HD_EMBREE_DEBUG_CODES_H
+#define PXR_IMAGING_PLUGIN_HD_EMBREE_DEBUG_CODES_H
+
+#include "pxr/pxr.h"
+#include "pxr/base/tf/debug.h"
+
+PXR_NAMESPACE_OPEN_SCOPE
+
+TF_DEBUG_CODES(
+    HDEMBREE_LIGHT_CREATE
+);
+
+PXR_NAMESPACE_CLOSE_SCOPE
+
+#endif // PXR_IMAGING_PLUGIN_HD_EMBREE_DEBUG_CODES_H