Jitter raster occlusion camera to reduce false positives.

Due to the low resolution of the occlusion buffer, small gaps between occluders can be closed and incorrectly occlude instances which should show through the gaps. To ameliorate this problem, this PR jitters the occlusion buffer over time, making it more likely an instance will be seen through a gap. This is used in conjunction with an occlusion timer per instance, to prevent instances flickering on and off rapidly.

1 files changed, 3 insertions, 1 deletions

diff --git a/servers/rendering/renderer_scene_cull.cpp b/servers/rendering/renderer_scene_cull.cpp
index aa69cd8539..16bc211a12 100644
--- a/servers/rendering/renderer_scene_cull.cpp
+++ b/servers/rendering/renderer_scene_cull.cpp
@@ -1720,6 +1720,7 @@ void RendererSceneCull::_update_instance(Instance *p_instance) {
 		idata.base_rid = p_instance->base;
 		idata.parent_array_index = p_instance->visibility_parent ? p_instance->visibility_parent->array_index : -1;
 		idata.visibility_index = p_instance->visibility_index;
+		idata.occlusion_timeout = 0;
 
 		for (Instance *E : p_instance->visibility_dependencies) {
 			Instance *dep_instance = E;
@@ -2775,7 +2776,7 @@ void RendererSceneCull::_scene_cull(CullData &cull_data, InstanceCullResult &cul
 #define VIS_RANGE_CHECK ((idata.visibility_index == -1) || _visibility_range_check<false>(cull_data.scenario->instance_visibility[idata.visibility_index], cull_data.cam_transform.origin, cull_data.visibility_viewport_mask) == 0)
 #define VIS_PARENT_CHECK (_visibility_parent_check(cull_data, idata))
 #define VIS_CHECK (visibility_check < 0 ? (visibility_check = (visibility_flags != InstanceData::FLAG_VISIBILITY_DEPENDENCY_NEEDS_CHECK || (VIS_RANGE_CHECK && VIS_PARENT_CHECK))) : visibility_check)
-#define OCCLUSION_CULLED (cull_data.occlusion_buffer != nullptr && (cull_data.scenario->instance_data[i].flags & InstanceData::FLAG_IGNORE_OCCLUSION_CULLING) == 0 && cull_data.occlusion_buffer->is_occluded(cull_data.scenario->instance_aabbs[i].bounds, cull_data.cam_transform.origin, inv_cam_transform, *cull_data.camera_matrix, z_near))
+#define OCCLUSION_CULLED (cull_data.occlusion_buffer != nullptr && (cull_data.scenario->instance_data[i].flags & InstanceData::FLAG_IGNORE_OCCLUSION_CULLING) == 0 && cull_data.occlusion_buffer->is_occluded(cull_data.scenario->instance_aabbs[i].bounds, cull_data.cam_transform.origin, inv_cam_transform, *cull_data.camera_matrix, z_near, cull_data.scenario->instance_data[i].occlusion_timeout))
 
 		if (!HIDDEN_BY_VISIBILITY_CHECKS) {
 			if ((LAYER_CHECK && IN_FRUSTUM(cull_data.cull->frustum) && VIS_CHECK && !OCCLUSION_CULLED) || (cull_data.scenario->instance_data[i].flags & InstanceData::FLAG_IGNORE_ALL_CULLING)) {
@@ -4252,6 +4253,7 @@ RendererSceneCull::RendererSceneCull() {
 	indexer_update_iterations = GLOBAL_GET("rendering/limits/spatial_indexer/update_iterations_per_frame");
 	thread_cull_threshold = GLOBAL_GET("rendering/limits/spatial_indexer/threaded_cull_minimum_instances");
 	thread_cull_threshold = MAX(thread_cull_threshold, (uint32_t)WorkerThreadPool::get_singleton()->get_thread_count()); //make sure there is at least one thread per CPU
+	RendererSceneOcclusionCull::HZBuffer::occlusion_jitter_enabled = GLOBAL_GET("rendering/occlusion_culling/jitter_projection");
 
 	dummy_occlusion_culling = memnew(RendererSceneOcclusionCull);