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, 4 insertions, 0 deletions

diff --git a/scene/3d/visual_instance_3d.h b/scene/3d/visual_instance_3d.h
index 7fed8095ef..68d29ef81e 100644
--- a/scene/3d/visual_instance_3d.h
+++ b/scene/3d/visual_instance_3d.h
@@ -120,6 +120,7 @@ private:
 	float extra_cull_margin = 0.0;
 	LightmapScale lightmap_scale = LIGHTMAP_SCALE_1X;
 	GIMode gi_mode = GI_MODE_DISABLED;
+	bool ignore_occlusion_culling = false;
 
 	const StringName *_instance_uniform_get_remap(const StringName p_name) const;
 
@@ -167,6 +168,9 @@ public:
 
 	void set_custom_aabb(AABB aabb);
 
+	void set_ignore_occlusion_culling(bool p_enabled);
+	bool is_ignoring_occlusion_culling();
+
 	GeometryInstance3D();
 };