In the BVH leaf nodes are a combination of two objects - a node object, and a leaf object. Testing revealed that in some situations node objects could be freed without also freeing the paired leaf object. This closes this bug.
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.
A common source of errors is to call functions (such as round()) expecting them to work in place, but them actually being designed only to return the processed value. Not using the return value in this case in indicative of a bug, and can be flagged as a warning by using the [[nodiscard]] attribute.
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.
Correct transformation of normals that works with a Basis containing non-uniform scale is difficult to get correct for those not familiar with the maths, it is also rather verbose and hard to read in calling code. This PR adds helper functions which both standardize the approach and make it clearer in calling code what is being done and why.
Sets `AlignOperands` to `DontAlign`.
`clang-format` developers seem to mostly care about space-based indentation and
every other version of clang-format breaks the bad mismatch of tabs and spaces
that it seems to use for operand alignment. So it's better without, so that it
respects our two-tabs `ContinuationIndentWidth`.
The pair user data wasn't correctly updated in the BVH from the check
pair callback.
This could lead to crashes when the check caused logical unpairing in
physics, then actual unpairing from the broadphase occured and the
physics server tried to delete an already deleted pointer.
The BVH implementation is not checking collision layers on existing
pairs on move like other physics broadphases do.
This is solved by adding a new call to trigger pair callbacks again so
the physics engine can check layers again (specific to the BVH version,
other broadphase implementations just trigger a move like before).
The previous error message incorrectly suggested that any Basis could be fixed by calling get_rotation_quation() or orthonormalize(). This PR points out that only a valid rotation Basis can be fixed in this way.
(cherry picked from commit d3a3b3aff3)
Added one more warning to the hideable warnings. These seem to be benign warnings and are hidden during use in rooms and portals. When used from other areas, only one warning is displayed per run, instead of for every occurrence.
The Transform::xform and xform_inv are made safe for Planes when using non-uniform scaling.
Basic unit tests for Transform.
Optimization of calling sites to prevent loss of performance from the changes to xform(Plane).
Clean: remove duplicate and interior vertices (uses Bullet algorithm)
Simplify: modify the geometry for further simplification (uses VHACD
algorithm)
In the editor, single convex hull now uses the clean option.
Added a new editor entry to create a simplified convex hull, can be
useful for creating convex hull from highly tessellated triangle meshes.
Specific change for 3.x:
Add support for Vector<Vector3> and PoolVector<Vector3> in the convex hull generator.
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.
The code is based on the current version of thirdparty/vhacd and modified to use Godot's types and code style.
Additional changes:
- backported and extended PagedAllocator to allow leaked objects
- applied patch from https://github.com/bulletphysics/bullet3/pull/3037
