Fix build when both Embree and Optix enabled

Author: Speierers

src/librender/shape.cpp

@@ -199,14 +199,18 @@ void embree_occluded(const RTCOccludedFunctionNArguments* args) {
 }
 
 MTS_VARIANT RTCGeometry Shape<Float, Spectrum>::embree_geometry(RTCDevice device) const {
-    RTCGeometry geom = rtcNewGeometry(device, RTC_GEOMETRY_TYPE_USER);
-    rtcSetGeometryUserPrimitiveCount(geom, 1);
-    rtcSetGeometryUserData(geom, (void *) this);
-    rtcSetGeometryBoundsFunction(geom, embree_bbox<Float, Spectrum>, nullptr);
-    rtcSetGeometryIntersectFunction(geom, embree_intersect<Float, Spectrum>);
-    rtcSetGeometryOccludedFunction(geom, embree_occluded<Float, Spectrum>);
-    rtcCommitGeometry(geom);
-    return geom;
+    if constexpr (!is_cuda_array_v<Float>) {
+        RTCGeometry geom = rtcNewGeometry(device, RTC_GEOMETRY_TYPE_USER);
+        rtcSetGeometryUserPrimitiveCount(geom, 1);
+        rtcSetGeometryUserData(geom, (void *) this);
+        rtcSetGeometryBoundsFunction(geom, embree_bbox<Float, Spectrum>, nullptr);
+        rtcSetGeometryIntersectFunction(geom, embree_intersect<Float, Spectrum>);
+        rtcSetGeometryOccludedFunction(geom, embree_occluded<Float, Spectrum>);
+        rtcCommitGeometry(geom);
+        return geom;
+    } else {
+        Throw("embree_geometry() should only be called in CPU mode.");
+    }
 }
 #endif