Use ThreadWorkPool to process physics step tasks in multiple threads. Collisions are all processed in parallel and solving impulses is
processed in parallel for rigid body islands.
Additional changes:
- Proper islands for soft bodies linked to active bodies
- All moving areas are on separate islands (can be parallelized)
- Fix inconsistencies with body islands (Kinematic bodies could link
bodies together or not depending on the processing order)
- Completely prevent static bodies to be active (it could cause islands
to be wrongly created and cause dangerous multi-threading operations as
well as inconsistencies in created islands)
- Apply impulses only on dynamic bodies to avoid unsafe multi-threaded
operations (static bodies can be on multiple islands)
- Removed inverted iterations when populating body islands, it's now
faster in regular order (maybe after fixing inconsistencies)
- Fixed SoftBody surface update with new rendering system
- Added GodotPhysics implementation for SoftBody
- Added support to get SoftBody rid to interact with the physics server
- Added support to get SoftBody bounds from the physics server
- Removed support for unused get_vertex_position and get_point_offset
from the physics server
- Removed SoftBody properties that are unused in both Bullet and
GodotPhysics (angular and volume stiffness, pose matching)
- Added RenderingServerHandler interface to PhysicsServer3D so the physics servers don't need to reference the class from SoftBody node directly
