Merge pull request #40 from pshriwise/fix-primitive-cull

Fix primitive culling

src/triangle_intersect.cpp

@@ -23,14 +23,15 @@ bool orientation_cull(const Direction& ray_dir, const Direction& normal, HitOrie
   return false;
 }
 
-bool primitive_mask_cull(RTCDRayHit* rayhit) {
+bool primitive_mask_cull(RTCDRayHit* rayhit, int primID) {
   if (!rayhit->ray.exclude_primitives) return false;
 
   RTCDRay& ray = rayhit->ray;
   RTCDHit& hit = rayhit->hit;
 
+
   // if the primitive mask is set, cull if the primitive is not in the mask
-  return std::find(ray.exclude_primitives->begin(), ray.exclude_primitives->end(), hit.primID) != ray.exclude_primitives->end();
+  return std::find(ray.exclude_primitives->begin(), ray.exclude_primitives->end(), primID) != ray.exclude_primitives->end();
 }
 
 void TriangleBoundsFunc(RTCBoundsFunctionArguments* args)
@@ -79,7 +80,7 @@ void TriangleIntersectionFunc(RTCIntersectFunctionNArguments* args) {
 
   if (rayhit->ray.rf_type == RayFireType::VOLUME) {
    if (orientation_cull(rayhit->ray.ddir, normal, rayhit->ray.orientation)) return;
-   if (primitive_mask_cull(rayhit)) return;
+   if (primitive_mask_cull(rayhit, primitive_ref.primitive_id)) return;
   }
 
   // if we've gotten through all of the filters, set the ray information

tests/test_ray_fire.cpp

@@ -74,4 +74,15 @@ TEST_CASE("Test Ray Fire Mesh Mock")
   intersection = rti->ray_fire(volume_tree, origin, direction, 5.1);
   REQUIRE(intersection.second != ID_NONE);
   REQUIRE_THAT(intersection.first, Catch::Matchers::WithinAbs(5.0, 1e-6));
+
+  // Test excluding primitives, fire a ray from the origin and log the hit face
+  // By providing the hit face as an excluded primitive in a subsequent ray fire,
+  // there should be no intersection returned
+  std::vector<MeshID> exclude_primitives;
+  intersection = rti->ray_fire(volume_tree, origin, direction, INFTY, &exclude_primitives);
+  REQUIRE_THAT(intersection.first, Catch::Matchers::WithinAbs(5.0, 1e-6));
+  REQUIRE(exclude_primitives.size() == 1);
+
+  intersection = rti->ray_fire(volume_tree, origin, direction, INFTY, &exclude_primitives);
+  REQUIRE(intersection.second == ID_NONE);
 }