1 files changed, 62 insertions, 1 deletions

diff --git a/modules/raycast/raycast_occlusion_cull.cpp b/modules/raycast/raycast_occlusion_cull.cpp
index 5005000eae..1153832feb 100644
--- a/modules/raycast/raycast_occlusion_cull.cpp
+++ b/modules/raycast/raycast_occlusion_cull.cpp
@@ -536,6 +536,64 @@ void RaycastOcclusionCull::buffer_set_size(RID p_buffer, const Vector2i &p_size)
 	buffers[p_buffer].resize(p_size);
 }
 
+Projection RaycastOcclusionCull::_jitter_projection(const Projection &p_cam_projection, const Size2i &p_viewport_size) {
+	if (!_jitter_enabled) {
+		return p_cam_projection;
+	}
+
+	// Prevent divide by zero when using NULL viewport.
+	if ((p_viewport_size.x <= 0) || (p_viewport_size.y <= 0)) {
+		return p_cam_projection;
+	}
+
+	Projection p = p_cam_projection;
+
+	int32_t frame = Engine::get_singleton()->get_frames_drawn();
+	frame %= 9;
+
+	Vector2 jitter;
+
+	switch (frame) {
+		default:
+			break;
+		case 1: {
+			jitter = Vector2(-1, -1);
+		} break;
+		case 2: {
+			jitter = Vector2(1, -1);
+		} break;
+		case 3: {
+			jitter = Vector2(-1, 1);
+		} break;
+		case 4: {
+			jitter = Vector2(1, 1);
+		} break;
+		case 5: {
+			jitter = Vector2(-0.5f, -0.5f);
+		} break;
+		case 6: {
+			jitter = Vector2(0.5f, -0.5f);
+		} break;
+		case 7: {
+			jitter = Vector2(-0.5f, 0.5f);
+		} break;
+		case 8: {
+			jitter = Vector2(0.5f, 0.5f);
+		} break;
+	}
+
+	// The multiplier here determines the divergence from center,
+	// and is to some extent a balancing act.
+	// Higher divergence gives fewer false hidden, but more false shown.
+	// False hidden is obvious to viewer, false shown is not.
+	// False shown can lower percentage that are occluded, and therefore performance.
+	jitter *= Vector2(1 / (float)p_viewport_size.x, 1 / (float)p_viewport_size.y) * 0.05f;
+
+	p.add_jitter_offset(jitter);
+
+	return p;
+}
+
 void RaycastOcclusionCull::buffer_update(RID p_buffer, const Transform3D &p_cam_transform, const Projection &p_cam_projection, bool p_cam_orthogonal) {
 	if (!buffers.has(p_buffer)) {
 		return;
@@ -550,7 +608,9 @@ void RaycastOcclusionCull::buffer_update(RID p_buffer, const Transform3D &p_cam_
 	Scenario &scenario = scenarios[buffer.scenario_rid];
 	scenario.update();
 
-	buffer.update_camera_rays(p_cam_transform, p_cam_projection, p_cam_orthogonal);
+	Projection jittered_proj = _jitter_projection(p_cam_projection, buffer.get_occlusion_buffer_size());
+
+	buffer.update_camera_rays(p_cam_transform, jittered_proj, p_cam_orthogonal);
 
 	scenario.raycast(buffer.camera_rays, buffer.camera_ray_masks.ptr(), buffer.camera_rays_tile_count);
 	buffer.sort_rays(-p_cam_transform.basis.get_column(2), p_cam_orthogonal);
@@ -596,6 +656,7 @@ void RaycastOcclusionCull::_init_embree() {
 RaycastOcclusionCull::RaycastOcclusionCull() {
 	raycast_singleton = this;
 	int default_quality = GLOBAL_GET("rendering/occlusion_culling/bvh_build_quality");
+	_jitter_enabled = GLOBAL_GET("rendering/occlusion_culling/jitter_projection");
 	build_quality = RS::ViewportOcclusionCullingBuildQuality(default_quality);
 }