Cycles: Ignore zero size instances in BVH

In certain types of animation it's possible to have some objects
scaling to zero. In this case we can save render times by avoid
traversing such instances.

Better to do ti ahead of a time, so traversal stays simple.

Reviewers: lukasstockner97, dingto, brecht

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D2048

3 files changed, 21 insertions, 0 deletions

diff --git a/intern/cycles/bvh/bvh_build.cpp b/intern/cycles/bvh/bvh_build.cpp
index 87a889955fe..d00de007b2d 100644
--- a/intern/cycles/bvh/bvh_build.cpp
+++ b/intern/cycles/bvh/bvh_build.cpp
@@ -205,6 +205,9 @@ void BVHBuild::add_references(BVHRange& root)
 
 	foreach(Object *ob, objects) {
 		if(params.top_level) {
+			if(!ob->is_traceable()) {
+				continue;
+			}
 			if(!ob->mesh->is_instanced()) {
 				num_alloc_references += ob->mesh->num_triangles();
 				num_alloc_references += count_curve_segments(ob->mesh);
@@ -226,6 +229,9 @@ void BVHBuild::add_references(BVHRange& root)
 
 	foreach(Object *ob, objects) {
 		if(params.top_level) {
+			if(!ob->is_traceable()) {
+				continue;
+			}
 			if(!ob->mesh->is_instanced())
 				add_reference_mesh(bounds, center, ob->mesh, i);
 			else
diff --git a/intern/cycles/render/object.cpp b/intern/cycles/render/object.cpp
index 9ee1a9ef7a6..644e581bf4b 100644
--- a/intern/cycles/render/object.cpp
+++ b/intern/cycles/render/object.cpp
@@ -225,6 +225,16 @@ vector<float> Object::motion_times()
 	return times;
 }
 
+bool Object::is_traceable()
+{
+	/* Mesh itself can be empty,can skip all such objects. */
+	if (bounds.size() == make_float3(0.0f, 0.0f, 0.0f)) {
+		return false;
+	}
+	/* TODO(sergey): Check for mesh vertices/curves. visibility flags. */
+	return true;
+}
+
 /* Object Manager */
 
 ObjectManager::ObjectManager()
diff --git a/intern/cycles/render/object.h b/intern/cycles/render/object.h
index 57614c95580..7ab73f3c91a 100644
--- a/intern/cycles/render/object.h
+++ b/intern/cycles/render/object.h
@@ -68,6 +68,11 @@ public:
 	void apply_transform(bool apply_to_motion);
 
 	vector<float> motion_times();
+
+	/* Check whether object is traceable and it worth adding it to
+	 * kernel scene.
+	 */
+	bool is_traceable();
 };
 
 /* Object Manager */