fixup wrong __BVH2__ redefinition from previous commit

ONEAPI_DEVICE_SELECTOR environment variable should be used instead of
SYCL_DEVICE_FILTER.

@@ -24,0 +43,4 @@
+#  define IF_NOT_USING_EMBREE
+#endif
+
+#define __BVH2__

@@ -281,6 +281,9 @@ endif()
 
 if(WITH_CYCLES_EMBREE)
   add_definitions(-DWITH_EMBREE)
+  if(EMBREE_SYCL_SUPPORT)

@@ -1545,2 +1545,4 @@
     )
 
+    use_oneapirt: BoolProperty(
+        name="Embree on GPU (Experimental)",

@@ -1546,1 +1546,4 @@
 
+    use_oneapirt: BoolProperty(
+        name="Embree on GPU (Experimental)",
+        description="Embree GPU execution will allow to use HW RT for ray tracing on Intel GPUs, which will provide better performance. However this support is experimental and some scenes may render incorrectly",

@@ -101,2 +101,3 @@
       rtc_device(NULL),
-      build_quality(RTC_BUILD_QUALITY_REFIT)
+      build_quality(RTC_BUILD_QUALITY_REFIT),
+      is_curve_support_required(false)

@@ -80,3 +80,3 @@
   bool has_peer_memory; /* GPU has P2P access to memory of another GPU. */
   bool has_gpu_queue;   /* Device supports GPU queue. */
-  bool use_metalrt;     /* Use MetalRT to accelerate ray queries (Metal only). */
+  bool use_hwrt;        /* Use hardware ray tracing to accelerate ray queries in a backend. */

@@ -112,6 +113,12 @@ static void device_iterator_cb(const char *id, const char *name, int num, void *
   /* NOTE(@nsirgien): Seems not possible to know from SYCL/oneAPI or Level0. */
   info.display_device = false;
 
+#  if WITH_EMBREE && WITH_EMBREE_GPU

@@ -34,1 +44,3 @@
-  bool is_finished_ok = create_queue(device_queue_, info.num);
+  if (use_hwrt)
+    VLOG_INFO
+        << "oneAPI will try to use Hardware Raytracing capabilities for intersection acceleration";

@@ -35,0 +55,4 @@
+#  ifdef WITH_EMBREE_GPU
+  use_hwrt = use_hwrt && (embree_device != nullptr);
+#  else
+  use_hwrt = false;

@@ -84,2 +115,3 @@
 {
-  return BVH_LAYOUT_BVH2;
+  /* MNEE and Raytrace kernels currently don't work correctly with HWRT. */
+  if ((kernel_features & KERNEL_FEATURE_MNEE || kernel_features & KERNEL_FEATURE_NODE_RAYTRACE)) {

@@ -88,0 +141,4 @@
+    if (bvh->params.top_level) {
+      embree_scene = bvh_embree->scene;
+    }
+    /* NOTE(sirgienko) We need to have an accumulative logic here, because Embree supports

@@ -103,1 +170,3 @@
-  is_finished_ok = oneapi_load_kernels(device_queue_, (const unsigned int)requested_features);
+  if (use_hwrt && !can_use_hwrt_for_features(requested_features)) {
+    VLOG_INFO << "Requested features don't work properly together with Hardware Raytracing yet "
+                 "in oneAPI backend. Hardware Raytracing is now disabled.";

@@ -450,0 +534,4 @@
+/* These declarations are missing from embree headers when compiling from a compiler that doesn't
+ * support SYCL. */
+extern "C" RTCDevice rtcNewSYCLDevice(sycl::context context, const char *config);
+extern "C" bool rtcIsSYCLDeviceSupported(const sycl::device sycl_device);

@@ -24,0 +36,4 @@
+    if (kernel_handler.get_specialization_constant<oneapi_embree_features>() != \
+        RTC_FEATURE_FLAG_NONE)
+#  define IF_NOT_USING_EMBREE \
+    if (kernel_handler.get_specialization_constant<oneapi_embree_features>() == \

@@ -8,0 +11,4 @@
+#  define __KERNEL_GPU_RAYTRACING__
+#endif
+
+#ifndef RTC_SYCL_KERNEL

@@ -146,0 +164,4 @@
+    return false;
+  if ((requested_features & KERNEL_FEATURE_VOLUME) == 0 &&
+      kernel_name.find("oneapi_kernel_integrator_intersect_volume_stack") != std::string::npos)
+    return false;

@@ -146,0 +178,4 @@
+  if (kernel_name.find("oneapi_kernel_integrator_shade_surface_raytrace") != std::string::npos)
+    return false;
+  if (kernel_name.find("oneapi_kernel_integrator_shade_surface_mnee") != std::string::npos)
+    return false;

@@ -146,0 +183,4 @@
+  return false;
+}
+
+bool oneapi_kernel_does_rt(::DeviceKernel device_kernel)