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).
These changes improve Rayshape behavior for Godot Physics 2D and 3D
when using move_and_slide with and without snapping.
Kinematic margin is now applied to ray shapes when handling snapping
collision tests and separation raycasts to help getting consistent
results in slopes and flat surfaces.
Recovery is calculated without the margin and a depth of 0 is still
considered a collision to stabilize results when on flat surface.
Recovery depth takes into account the current recovery vector (just like
test_body_motion) to fix jittering issues with multiple ray shapes due
to applying too much recovery.
Allows more flexible collision detection with different safe margin values.
Kinematic body motion changes in 2D and 3D:
-Recovery only for depth > min contact depth to help with collision
detection consistency (rest info could be lost if recovery was too much)
-Adaptive min contact depth (based on margin) instead of space parameter
Same thing that was already done in 2D, applies moving platform motion
by using a call to move_and_collide that excludes the platform itself,
instead of making it part of the body motion.
Helps with handling walls and slopes correctly when the character walks
on the moving platform.
Also made some minor adjustments to the 2D version and documentation.
Co-authored-by: fabriceci <fabricecipolla@gmail.com>
When synchronizing KinematicBody motion with moving the platform using
direct body state, only the linear velocity was taken into account.
This change exposes velocity at local point in direct body state and
uses it in move_and_slide to get the proper velocity that includes
rotations.
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).
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.
* Safe and unsafe motion are calculated by dichotomy with a limited
number of steps. It's good for performance, but on long motions that
either collide near the beginning or near the end, the result can be
very imprecise.
* Now a factor 0.25 or 0.75 is used to converge faster when this case
happens, which allows longer motions to get more accurate collision
detection.
* Makes snap collision more precise, and helps with cases where diagonal collision on the border of a platform can lead to the character being stuck.
Additional improvements to move_and_slide:
* Handle slide canceling in move_and_collide with 0 velocity instead of
not applying it.
* Better handling of snap with custom logic to cancel sliding.
* Remove small jittering when using stop on slope, by canceling the
motion completely when the resulting motion is less than margin instead
of always projecting to the up direction (in both body motion and snap).
Co-authored-by: fabriceci <fabricecipolla@gmail.com>
Make sure the direction of the motion is preserved, unless the depth is
higher than the margin, which means the body needs depenetration in any
direction.
Also changed move_and_slide to avoid sliding on the first motion, in
order to avoid issues with unstable position on ground when jumping.
Co-authored-by: fabriceci <fabricecipolla@gmail.com>
In 3D, disabled shapes are now not added to the broadphase anymore.
Since they are removed right away when disabled, no need to check for
disabled shapes for any query that comes from the broadphase.
Also Fixes raycast queries returning disabled shapes.
In 2D, disabled shapes where already not added to the broadphase.
Remove the same unnecessary checks as in 3D.
Overall harmonized API for disabled shapes in the physics servers and
removed duplicate method.
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
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.
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.
3.3 version of #47130
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.
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.
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.
