Ability to visually debug geometry visually:

-Visible 2D and 3D Shapes, Polygons, Tile collisions, etc.
-Visible Navmesh and Navpoly
-Visible collision contacts for 2D and 3D as a red point
-Customizable colors in project settings

modules/gridmap/grid_map.h

@@ -93,6 +93,8 @@ class GridMap : public Spatial {
 
 		Ref<Mesh> baked;
 		RID bake_instance;
+		RID collision_debug;
+		RID collision_debug_instance;
 
 		bool dirty;
 		RID static_body;