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.
Margin needs to have a high enough value for test body motion to work
properly (separate using the margin, move without then gather rest info
with the margin again).
Fixes issues with test motion returning no collision in some cases with
margin equal to 0.
(cherry picked from commit 0c354047e1)
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
* 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>
Fixing by applying the movement in two steps, first the platform
movement, and then the body movement. Plus, add the platform movement
when we are on_wall.
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.
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.
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 🎆
(cherry picked from commit b5334d14f7)
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>
- 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.
Happy new year to the wonderful Godot community!
We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.
Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
