Refactors the BVH to make it more generic and customizable. Instead of hard coding the system of pairable_mask and pairable_type into the BVH, this information is no longer stored internally, and instead the BVH uses callbacks both for determining whether pairs of objects can pair with each other, and for filtering cull / intersection tests.
In addition, instead of hard coding the number of trees, the BVH now supports up to 32 trees, and each object can supply a tree collision mask to determine which trees it can collide against.
This enables the BVH to scale to either the two or 3 trees needed in physics, and the single tree used without pairing in Godot 4 render tree.
This PR adds a define BVH_EXPAND_LEAF_AABBS which is set, which stores expanded AABBs in the tree instead of exact AABBs.
This makes the logic less error prone when considering reciprocal collisions in the pairing, as all collision detect is now taking place between expanded AABB against expanded AABB, rather than expanded AABB against exact AABB.
The flip side of this is that the intersection tests will now be less exact when expanded margins are set.
All margins are now user customizable via project settings, and take account of collision pairing density to adjust the margin dynamically.
Although the expanded bounds were working in normal use, for moving and growing objects, there was one case which was not dealt with properly - significant shrinkage of exact bounds within an expanded bound.
This PR detects significant shrinkage and forces a new expanded bound to be created.
Changes passing of current_tree from a member variable to a function argument, making bugs due to stale state less likely.
Fix a bug in deactivate where current_tree variable was stale. This may have resulted in visual anomalies.
Dynamic BVH doesn't update the tree anymore when calling set_pairable
with no parameter change.
Also modified Godot Physics broadphase to create objects directly with
pairable (static) set correctly to make use of this optimization for the
BVH broadphase.
Note: Octree broadphase doesn't use this optimization because it forces
an update on move, so passing the proper AABB and static parameters on
creation would cause the tree to update twice.
List of changes:
- Modified bvh class to handle 2D and 3D as a template
- Changes in Rect2, Vector2, Vector3 interface to uniformize template
calls
- New option in Project Settings to enable BVH for 2D Physics (enabled
by default like in 3D)
A major feature lacking in the octree was proper support for setting visibility / activation. This meant that invisible objects were still causing lots of processing in the tree unnecessarily.
This PR adds proper support for activation, items are temporarily removed from the tree and collision detection when inactive.
Calling set_pairable now will update collisions (rather than waiting for the next item_move).
Mask behaviour used for pairing now (hopefully) matches octree.
Complete rewrite of spatial partitioning using a bounding volume hierarchy rather than octree.
Switchable in project settings between using octree or BVH for rendering and physics.
lawnjelly
Rémi Verschelde
PouleyKetchoupp