Implement occlusion culling

Added an occlusion culling system with support for static occluder meshes.
It can be enabled via `Project Settings > Rendering > Occlusion Culling > Use Occlusion Culling`.

Occluders are defined via the new `Occluder3D` resource and instanced using the new
`OccluderInstance3D` node. The occluders can also be automatically baked from a
scene using the built-in editor plugin.

1 files changed, 20 insertions, 3 deletions

diff --git a/scene/main/viewport.cpp b/scene/main/viewport.cpp
index 4c9ebe016e..f1613f2fe5 100644
--- a/scene/main/viewport.cpp
+++ b/scene/main/viewport.cpp
@@ -3242,6 +3242,21 @@ float Viewport::get_lod_threshold() const {
 	return lod_threshold;
 }
 
+void Viewport::set_use_occlusion_culling(bool p_use_occlusion_culling) {
+	if (use_occlusion_culling == p_use_occlusion_culling) {
+		return;
+	}
+
+	use_occlusion_culling = p_use_occlusion_culling;
+	RS::get_singleton()->viewport_set_use_occlusion_culling(viewport, p_use_occlusion_culling);
+
+	notify_property_list_changed();
+}
+
+bool Viewport::is_using_occlusion_culling() const {
+	return use_occlusion_culling;
+}
+
 void Viewport::set_debug_draw(DebugDraw p_debug_draw) {
 	debug_draw = p_debug_draw;
 	RS::get_singleton()->viewport_set_debug_draw(viewport, RS::ViewportDebugDraw(p_debug_draw));
@@ -3331,9 +3346,6 @@ bool Viewport::is_handling_input_locally() const {
 	return handle_input_locally;
 }
 
-void Viewport::_validate_property(PropertyInfo &property) const {
-}
-
 void Viewport::set_default_canvas_item_texture_filter(DefaultCanvasItemTextureFilter p_filter) {
 	ERR_FAIL_INDEX(p_filter, DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_MAX);
 
@@ -3478,6 +3490,9 @@ void Viewport::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_use_debanding", "enable"), &Viewport::set_use_debanding);
 	ClassDB::bind_method(D_METHOD("is_using_debanding"), &Viewport::is_using_debanding);
 
+	ClassDB::bind_method(D_METHOD("set_use_occlusion_culling", "enable"), &Viewport::set_use_occlusion_culling);
+	ClassDB::bind_method(D_METHOD("is_using_occlusion_culling"), &Viewport::is_using_occlusion_culling);
+
 	ClassDB::bind_method(D_METHOD("set_debug_draw", "debug_draw"), &Viewport::set_debug_draw);
 	ClassDB::bind_method(D_METHOD("get_debug_draw"), &Viewport::get_debug_draw);
 
@@ -3574,6 +3589,7 @@ void Viewport::_bind_methods() {
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "msaa", PROPERTY_HINT_ENUM, "Disabled,2x,4x,8x,16x,AndroidVR 2x,AndroidVR 4x"), "set_msaa", "get_msaa");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "screen_space_aa", PROPERTY_HINT_ENUM, "Disabled,FXAA"), "set_screen_space_aa", "get_screen_space_aa");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_debanding"), "set_use_debanding", "is_using_debanding");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "use_occlusion_culling"), "set_use_occlusion_culling", "is_using_occlusion_culling");
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "lod_threshold", PROPERTY_HINT_RANGE, "0,1024,0.1"), "set_lod_threshold", "get_lod_threshold");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "debug_draw", PROPERTY_HINT_ENUM, "Disabled,Unshaded,Overdraw,Wireframe"), "set_debug_draw", "get_debug_draw");
 	ADD_GROUP("Canvas Items", "canvas_item_");
@@ -3655,6 +3671,7 @@ void Viewport::_bind_methods() {
 	BIND_ENUM_CONSTANT(DEBUG_DRAW_CLUSTER_SPOT_LIGHTS);
 	BIND_ENUM_CONSTANT(DEBUG_DRAW_CLUSTER_DECALS);
 	BIND_ENUM_CONSTANT(DEBUG_DRAW_CLUSTER_REFLECTION_PROBES);
+	BIND_ENUM_CONSTANT(DEBUG_DRAW_OCCLUDERS)
 
 	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_NEAREST);
 	BIND_ENUM_CONSTANT(DEFAULT_CANVAS_ITEM_TEXTURE_FILTER_LINEAR);