For 2D:
Raycast CCD now works the same as in 3D, it changes the body's velocity
to place it at the impact position instead of generating a contact point
that causes a wrong push back.
For both 2D and 3D:
The raycast CCD process reads and modifies body velocities, so it needs
to be moved to pre_solve() instead of setup() to be processed linearly
on the main thread, otherwise multithreading can cause some CCD results
to be randomly lost when multiple collisions occur.
Makes the API for forces and impulses more flexible, easier to
understand and harmonized between 2D and 3D.
Rigid bodies now have 3 sets of methods for forces and impulses:
-apply_impulse() for impulses (one-shot and time independent)
-apply_force() for forces (time dependent) applied for the current step
-add_constant_force() for forces that keeps being applied each step
Also updated the documentation to clarify the different methods and
parameters in rigid body nodes, body direct state and physics servers.
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.
Helps with discovery and setup of physics solver settings, in a specific
project settings section for both 2D and 3D.
Other changes for cleanup:
-Removed unused space parameters in 3D
SPACE_PARAM_BODY_ANGULAR_VELOCITY_DAMP_RATIO
SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS
-Added custom solver bias for Shape3D (same as Shape2D)
-Improved documentation for solver settings
Clarified space parameters for contacts and added missing ones.
List of changes:
-Add contact bias to space parameters
-Add solver iterations to space parameters, instead of a specific
physics server function
-Renamed BODY_MAX_ALLOWED_PENETRATION to CONTACT_MAX_ALLOWED_PENETRATION
to make it consistent with other contact parameters
Changed the algorithm for solving contacts to keep previous contacts as
long as they are under the max separation threshold to keep contact
impulses more consistent and contacts more stable.
Also made 2D consistent with 3D and changed some default parameters:
-Contact bias is now 0.8 instead of 0.3 to avoid springy contacts
-Solver iterations are 16 instead of 8 by default for better stability
Performance considerations:
Tested with stress tests that include lots of contacts from overlapping
bodies.
3D: There's no measurable difference in performance.
2D: Performance is a bit lower (close to 10% slower in extreme cases)
The benefit for 2D physics to be much more stable outweighs the slight
decrease in performance, and this could be alleviated by changing the
algorithm to use jacobians for contact solving to help with cache
efficiency and memory allocations.
Bounce calculation now uses the previous frame's velocity, so it's
consistent with the actual motion of the bodies involved and not the
yet-to-be-applied forces.
When bounce is 1, using the current velocity was causing the new forces
(including gravity) to be taken into account, which lead to the bounce
velocity to be higher than the falling velocity at the moment of impact,
adding more and more energy over time.
Regression fix, gravity was accumulated between frames after some
changes around area gravity calculation.
Also got rid of unused member and method in soft body class.
Replaced the previous implementation for backface collision handling (in
test_axis function from SAT algorithm) with much simpler logic in the
collision generation phase with face shapes, in order to get rid of
wrong contacts when backface collision is disabled.
Now it just ignores the generated collision if the contact normal is
against the face normal, with a threshold to keep edge contacts.
Added a special case for soft bodies to invert the collision instead of
ignoring it, because for now it's the best solution to avoid soft bodies
to go through concave shapes (they use small spheres). This might be
replaced with a better algorithm for soft bodies later.
Updating the broadphase to find new collision pairs was done after
checking for collision islands, so it was working in most cases due to
the pairing margin used in the BVH, but in case of teleported objects
the narrowphase collision could be skipped.
Now it's done before checking for collision islands, so we can ensure
that broadphase pairing has been done at the same time as objects are
marked as moved so their collision can be checked properly.
This issue didn't happen in the Octree/HashGrid because they do nothing
on update and trigger pairs directly when objects move instead.
In all physics servers, body_get_direct_state() now silently returns
nullptr when the body has been already freed or is removed from space,
so the client code can detect this state and invalidate the body rid.
In 2D, there is no change in behavior (just no more errors).
In 3D, the Bullet server returned a valid direct body state when the
body was removed from the physics space, but in this case it didn't
make sense to use the information from the body state.
Center of mass in body's local space is more useful than the transformed
one in some cases, like drawing its position for debug.
It's especially useful to get the generated local center of mass when
in auto mode (by default).
Physics Server BODY_PARAM_CENTER_OF_MASS:
Now always returns the local center of mass, instead of setting a local
center of mass and getting a transformed one.
This causes compatibility breaking, but it makes more sense for the
parameter to be consistent between getter and setter.
Direct Body State:
There are now two properties, because both of them can be useful in
different situations.
center_of_mass: relative position in global coordinates (same as before)
center_of_mass_local: position in local coordinates
Same as what is already done for shape queries, applied to point and ray
queries. Easier to document and more flexible to add more parameters.
Also expose intersect_point method to script in 3D.
Remove intersect_point_on_canvas in 2D, replaced with a parameter.
Sets `AlignOperands` to `DontAlign`.
`clang-format` developers seem to mostly care about space-based indentation and
every other version of clang-format breaks the bad mismatch of tabs and spaces
that it seems to use for operand alignment. So it's better without, so that it
respects our two-tabs `ContinuationIndentWidth`.
Damping values are now non-negative.
Add new properties linear_damp_mode and angular_damp_mode to set the way
RigidDynamicBody and PhysicalBone (2D & 3D) use damping values.
It can now be Combine (default) to add to the default/areas, or Replace
to override the value completely (current behavior).
* Made the Basis euler orders indexed via enum.
* Node3D has a new rotation_order property to choose Euler rotation order.
* Node3D has also a rotation_mode property to choose between Euler, Quaternion and Basis
Exposing these modes as well as the order makes Godot a lot friendlier for animators, which can choose the best way to interpolate rotations.
The new *Basis* mode makes the (exposed) transform property obsolete, so it was removed (can still be accessed by code of course).
Changing the collision layer of a sleeping body was not triggering area
updates correctly.
Bodies need to be active for collision to be checked against already
overlapping bodies and areas.
Neighbors need to be activated too in order to handle the case where a
static body is modified (it can't be activated directly but paired
bodies need to check their collision again).
In 3D, moved the call to wakeup() from the physics server to
GodotBody3D::_shapes_changed to make it consistent with 2D and also
handle the case where shapes are modified (_shapes_changed is called in
both this case and collision layer changes).
Proper logic for changing physics state when disabled and disabled mode
is changed (it was unnecessarily making calls to re-initialize physics).
Extra error handling in soft body implementations to avoid crashes with
invalid mesh.
Same logic as what was done in 3D, applied to 2D center of mass.
Also did some minor cleanup in 3D and fixed center of mass transform
during the first frame after teleporting a dynamic body.
Added a parameter in test_body_motion to exclude attached objects from
collision, used to avoid collision with all TileMap tiles with moving
platform motion instead of just the one tile the character touches.
Same changes made in 3D for consistency, and handling potential similar
cases.
-Physics servers test body motion use a class to hold parameters instead
of multiple arguments to make it more readable and flexible since there
are many options
-Improved documentation for test body motion and kinematic collision
-Removed read-only properties for body motion results (not handled in
scripts, so they should be get_ methods only instead)
Shape metadata was only used to get tile information when colliding with
tilemaps. It's not needed anymore since there's an API in tilemap using
body ids instead.
Allows 2D character controller to work without applying gravity when
touching the ground (also more safely in 3D), and collision detection
is more flexible with different safe margin values.
Character 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
Extra CharacterBody changes:
-2D: apply changes made in 3D for stop on slope and floor snap that help
fixing some jittering cases
-3D: fix minor inconsistencies in stop on slope and floor snap logic
RigidDynamicBody modes are replaced with several properties to make their
usage clearer:
-lock_rotation: disable body's rotation (instead of MODE_LOCKED)
-freeze: no gravity or forces (instead of MODE_STATIC and MODE_KINEMATIC)
-freeze_mode: Static (can be only teleported) or Kinematic (can be animated)
Also renamed MODE_DYNAMIC_LOCKED to MODE_DYNAMIC_LINEAR in the physics
servers.
Changes:
-Added support for custom inertia and center of mass in 3D
-Added support for custom center of mass in 2D
-Calculated center of mass from shapes in 2D (same as in 3D)
-Fixed mass properties calculation with disabled shapes in 2D/3D
-Removed first_integration which is not used in 2D and doesn't seem to
make a lot of sense (prevents omit_force_integration to work during the
first frame)
-Support for custom inertia on different axes for RigidBody3D
Instead of having a physics node named Static that can be either Static
or Kinematic, AnimatableBody is added again as a separate node:
-Inherited from StaticBody to make its usage clearer
-Still separated from CharacterBody to make its usage more focused
Properly implemented constant velocity for kinematic bodies in godot
physics servers (induced velocity without actually moving).
Also updated description for the different physics nodes to make their
usage clearer.
The default mask for queries was 0, 0x7FFFFFFF or 0xFFFFFFFF depending
on the cases.
Now always using 0xFFFFFFFF (in the form of UINT32_MAX to make it clear)
in order to use all layers by default.
Use a C++ callback instead of Callable for synchronizing physics nodes' state with physics servers.
Remove usage of PhysicsDirectBodyState in physics nodes when not
necessary.
Store PhysicsDirectBodyState for bodies individually instead of a
singleton to avoid issues when accessing direct body state for multiple
bodies.
PhysicsDirectBodyState is initialized only when needed, so it doesn't
have to be created when using the physics server directly.
Move PhysicsDirectBodyState2D and PhysicsDirectBodyState3D to separate
cpp files.
Make separation ray shapes work properly in move_and_slide, wihtout the
specific code in CharacterBody like before.
Now most of the logic is handled inside the physics server. The only
thing that's needed is to use ray shapes only for recovery and ignore
them when performing the motion itself (unless we're snapping or slips
on slope is on).
One-way collision is disabled for both rigid bodies and character
bodies.
Kinematic margin is now applied to ray shapes to help getting consistent
results in slopes and flat surfaces.
Convex shapes don't return inverted normals when a segment test starts
inside (raycasting will be made consistent in a separate patch).
Ray shapes also discard contacts when fully contained inside a shape
and when the contact direction is inverted, so the behavior is
consistent with all shape types. Now they always separate only when
intersecting the top of a shape (for downward rays).
Removing the + 1 in point gravity formula when using distance scale to
make it more accurate for standard gravitation.
Fixes precession in orbits for games using gravitation.
Also moved gravity calculation to area to use it for both rigid bodies
and soft bodies in 3D (same change in 2D for consistency).
Co-authored-by: Ryan Peach <ryan.peach@keysight.com>
