The code is based on the current version of thirdparty/vhacd and modified to use Godot's types and code style.
Additional changes:
- extended PagedAllocator to allow leaked objects
- applied patch from https://github.com/bulletphysics/bullet3/pull/3037
Port lawnjelly's dynamic BVH implementation from 3.x to be used in
both 2D and 3D broadphases.
Removed alternative broadphase implementations which are not meant to be
used anymore since they are much slower.
Includes changes in Rect2, Vector2, Vector3 that help with the template
implementation of the dynamic BVH by uniformizing the interface between
2D and 3D math.
Co-authored-by: lawnjelly <lawnjelly@gmail.com>
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)
Several optimizations in the way solver islands are processed in both
2D and 3D physics:
- Use LocalVector instead of linked list to avoid cache misses (with
persistent storage based on worst case scenario)
- Remove pairs when setup fails (no valid contact) to avoid unnecessary
solving of non-colliding rigid bodies just to return immediately
The moment of inertia calculation for BoxShape is:
```
Vector3(
(p_mass / 3.0) * (ly * ly + lz * lz),
(p_mass / 3.0) * (lx * lx + lz * lz),
(p_mass / 3.0) * (lx * lx + ly * ly));
```
where the final line includes both the x and y extents.
However, for CapsuleShape3D, CylinderShape3D, ConvexPolygonShape3D, ConcavePolygonShape3D, and HeightMapShape3D, the final line read `(p_mass / 3.0) * (extents.y * extents.y + extents.y * extents.y)`. I believe this is a mistake, considering the comment in each case mentions using an AABB approximation, which should follow the same approach as BoxShape.
This change corrects the final line to include both the x and y components of the shape's extent.
The angular velocity estimate for kinematic bodies was calculated
incorrectly. Also, fixes its use in some kinematic/rigid collision
calculations.
This fixes#47029.
Helps a lot with soft bodies and generally useful to avoid shapes to go
through the ground in certain cases.
Added an option in ConcavePolygonShape to re-enable backface collision
on specific bodies if needed.
- 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
Test specific axes before falling back to GJK-EPA algorithm to get more
accurate separation axes for common cases, the same way it's done for
cylinder-cylinder collision.
In the case of falling back to GJK-EPA algorithm to generate cylinder
contact points, margins were never taken into account.
This fixes the depenetration phase for kinematic bodies and allows
consistent floor detection for cylinder shapes.
In 3D, collision is disabled between kinematic/static bodies when
contacts are generated only to report them.
In 2D, this case was already fixed but the code is cleaned to make it
easier to follow.
Fixes#46738 by setting the default inertia to a valid value when there are no valid shapes for a 3d body.
Changed the comment style for the update_inertias method as well.
Joint3DSW instances are also destroyed without explicitly calling free()
for example when changing constrainted bodies at runtime using
set_node method.
This change makes test_body_motion more reliable when the kinematic body
recovers from being stuck.
- When recovery occurs, the rest information is generated, in order to
make sure collision results from test_move, move_and_collide and
move_and_slide are consistent and return a collision in case of overlap.
- The new calculation for recovery vector makes sure the recovery is
never more than the overlap depth between shapes.
This can help with cases where the kinematic body overlaps with several
shapes.
Recovery is made iteratively, without forcing a full overlap at each
step. This helps with getting proper rest information when recovery
occurs.
- One Way Collision:
When attempting motion, contact direction is checked against motion
before skipping in order to solve cases where kinematic bodies can sink
into one-way collision shapes.
Rest info now sets max contact depth in order to properly handle one-way
collision.
- Low speed motion is now handled in the rest info, by never setting
min_allowed_depth lower than motion length.
Separation is always applied with full margin, otherwise contact is lost
when low speed motion occurs right after higher speed motion.
- Similar changes are applied to 3D in order to make 2D and 3D
consistent.
Cylinder contact points generation is adjusted to make it more stable
when standing on triangle meshes.
Point-Circle:
Switched to simpler plane projection as it's done for Point-Face contact
points. It solves some cases where discrepancies between the two points
caused the cylinder to jump.
Edge-Circle:
Same as before, the case for edge has just been moved from Face-Circle
to a specific method.
Face-Circle:
The previous method was clipping edges against the circle, and then
tried to add contact points when there wasn't enough support and failed
in some cases.
Now using a different algorithm which adds proper contact points around
the circle more consistently.
First, by clipping edges against circle segments using Face-Face
algorithm.
Second, by clipping edges against the circle plane.
Cylinder collision detection uses a mix of SAT and GJKEPA.
GJKEPA is used to find the best separation axis in cases where finding
it analytically is too complex.
Changes in SAT solver:
Added support for generating separation axes for cylinder shape.
Added support for generating contact points with circle feature.
Changes in GJKEPA solver:
Updated from latest Bullet version which includes EPA fixes in some
scenarios.
Setting a lower EPA_ACCURACY to fix accuracy problems with cylinder vs.
cylinder in some cases.
-Rendering server now uses a split RID allocate/initialize internally, this allows generating RIDs immediately but initialization to happen later on the proper thread (as rendering APIs generally requiere to call on the right thread).
-RenderingServerWrapMT is no more, multithreading is done in RenderingServerDefault.
-Some functions like texture or mesh creation, when renderer supports it, can register and return immediately (so no waiting for server API to flush, and saving staging and command buffer memory).
-3D physics server changed to be made multithread friendly.
-Added PhysicsServer3DWrapMT to use 3D physics server from multiple threads.
-Disablet Bullet (too much effort to make multithread friendly, this needs to be fixed eventually).
This change allows collide_shape, intersect_shape, cast_motion and
rest_info in both 2D and 3D to ignore disabled shapes and make them
consistent with the physics simulation.
In some other cases, _cull_aabb_for_body is used and filters shapes out
internally, but whenever a physics query uses the broadphase directly
without calling _cull_aabb_for_body, disabled shapes can be returned
and need to be filtered out.
For RigidBodies, uses the collision normal determined by relative motion
to determine whether or not a one-way collision has occurred.
For KinematicBodies, performs additional checks to ensure a one-way
collision has occurred, and averages the recovery step over all collision
shapes.
Co-authored-by: Sergej Gureev <sergej.gureev@relex.fi>
Happy new year to the wonderful Godot community!
2020 has been a tough year for most of us personally, but a good year for
Godot development nonetheless with a huge amount of work done towards Godot
4.0 and great improvements backported to the long-lived 3.2 branch.
We've had close to 400 contributors to engine code this year, authoring near
7,000 commit! (And that's only for the `master` branch and for the engine code,
there's a lot more when counting docs, demos and other first-party repos.)
Here's to a great year 2021 for all Godot users 🎆
- Fixes Godot physics failing when the cast Shape is inside of, or
already colliding with another Shape.
- Fixes Bullet physics failing when there is no motion.
- Ensures Godot and Bullet physics behave the same.
- Updates the documentation to exclude the caveats for the failures and
differences.
