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.
When set_static is called on a newly added object, the forced collision
check in BVH set_pairable was using an empty AABB, which caused
unnecessary collision checks at the origin, then a call to move was
checking again at the right position.
These changes ensure broadphase objects are added to the BVH tree with
proper AABB so collision checks are correctly done right away.
Octree & Basic broadphase trees are not affected by these changes.
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)
Complete rewrite of spatial partitioning using a bounding volume hierarchy rather than octree.
Switchable in project settings between using octree or BVH for rendering and physics.
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.
Configured for a max line length of 120 characters.
psf/black is very opinionated and purposely doesn't leave much room for
configuration. The output is mostly OK so that should be fine for us,
but some things worth noting:
- Manually wrapped strings will be reflowed, so by using a line length
of 120 for the sake of preserving readability for our long command
calls, it also means that some manually wrapped strings are back on
the same line and should be manually merged again.
- Code generators using string concatenation extensively look awful,
since black puts each operand on a single line. We need to refactor
these generators to use more pythonic string formatting, for which
many options are available (`%`, `format` or f-strings).
- CI checks and a pre-commit hook will be added to ensure that future
buildsystem changes are well-formatted.
(cherry picked from commit cd4e46ee65)
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.
