feat: add PD and PID controller implementations

CHANGELOG.md

@@ -1,27 +1,41 @@
+## Unreleased
+
+### Added
+
+- Add `PdController` and `PidController` for making it easier to control dynamic rigid-bodies at the velocity level.
+  This can for example be used as a building block for a dynamic character controller.
+- Add `RigidBodyPosition::pose_errors` which computes the translational and rotational delta between
+  `RigidBodyPosition::position` and `::next_position`.
+- Implement `Sub` for `RigidBodyVelocity`.
+- Add `RigidBody::local_center_of_mass()` to get its center-of-mass in the rigid-body’s local-space.
+
 ## v0.23.0 (08 Jan 2025)
 
 ### Fix
 
-- The broad-phase region key has been replaced by an i64 in the f64 version of rapier, increasing the range before panics occur.
+- The broad-phase region key has been replaced by an i64 in the f64 version of rapier, increasing the range before
+  panics occur.
 - Fix `BroadphaseMultiSap` not being able to serialize correctly with serde_json.
-- Fix `KinematicCharacterController::move_shape` not respecting parameters `max_slope_climb_angle` and `min_slope_slide_angle`.
+- Fix `KinematicCharacterController::move_shape` not respecting parameters `max_slope_climb_angle` and
+  `min_slope_slide_angle`.
 - Improve ground detection reliability for `KinematicCharacterController`. (#715)
 - Fix wasm32 default values for physics hooks filter to be consistent with native: `COMPUTE_IMPULSES`.
 - Fix changing a collider parent when ongoing collisions should be affected (#742):
-  - Fix collisions not being removed when a collider is parented to a rigidbody while in collision with it.
-  - Fix collisions not being added when the parent was removed while intersecting a (previously) sibling collider.
+    - Fix collisions not being removed when a collider is parented to a rigidbody while in collision with it.
+    - Fix collisions not being added when the parent was removed while intersecting a (previously) sibling collider.
 
 ### Added
 
 - `RigidBodySet` and `ColliderSet` have a new constructor `with_capacity`.
 - Use `profiling` crate to provide helpful profiling information in different tools.
-  - The testbeds have been updated to use `puffin_egui`
+    - The testbeds have been updated to use `puffin_egui`
 
 ### Modified
 
 - `InteractionGroups` default value for `memberships` is now `GROUP_1` (#706)
 - `ImpulseJointSet::get_mut` has a new parameter `wake_up: bool`, to wake up connected bodies.
-- Removed unmaintained `instant` in favor of `web-time`. This effectively removes the `wasm-bindgen` transitive dependency as it's no longer needed.
+- Removed unmaintained `instant` in favor of `web-time`. This effectively removes the `wasm-bindgen` transitive
+  dependency as it's no longer needed.
 - Significantly improve performances of `QueryPipeline::intersection_with_shape`.
 
 ## v0.22.0 (20 July 2024)
@@ -748,7 +762,8 @@ Several new shape types are now supported:
 
 It is possible to build `ColliderDesc` using these new shapes:
 
-- `ColliderBuilder::round_cuboid`, `ColliderBuilder::segment`, `ColliderBuilder::triangle`, `ColliderBuilder::round_triangle`,
+- `ColliderBuilder::round_cuboid`, `ColliderBuilder::segment`, `ColliderBuilder::triangle`,
+  `ColliderBuilder::round_triangle`,
   `ColliderBuilder::convex_hull`, `ColliderBuilder::round_convex_hull`, `ColliderBuilder::polyline`,
   `ColliderBuilder::convex_decomposition`, `ColliderBuilder::round_convex_decomposition`,
   `ColliderBuilder::convex_polyline` (2D only), `ColliderBuilder::round_convex_polyline` (2D only),

examples2d/all_examples2.rs

@@ -43,6 +43,8 @@ mod s2d_pyramid;
 mod sensor2;
 mod trimesh2;
 
+mod utils;
+
 #[cfg_attr(target_arch = "wasm32", wasm_bindgen(start))]
 pub fn main() {
     let mut builders: Vec<(_, fn(&mut Testbed))> = vec![

examples2d/character_controller2.rs

@@ -1,3 +1,6 @@
+use crate::utils::character;
+use crate::utils::character::CharacterControlMode;
+use rapier2d::control::{KinematicCharacterController, PidController};
 use rapier2d::prelude::*;
 use rapier_testbed2d::Testbed;
 use std::f32::consts::PI;
@@ -25,7 +28,12 @@ pub fn init_world(testbed: &mut Testbed) {
     /*
      * Character we will control manually.
      */
-    let rigid_body = RigidBodyBuilder::kinematic_position_based().translation(vector![-3.0, 5.0]);
+    let rigid_body = RigidBodyBuilder::kinematic_position_based()
+        .translation(vector![-3.0, 5.0])
+        // The two config below makes the character
+        // nicer to control with the PID control enabled.
+        .gravity_scale(10.0)
+        .soft_ccd_prediction(10.0);
     let character_handle = bodies.insert(rigid_body);
     let collider = ColliderBuilder::capsule_y(0.3, 0.15);
     colliders.insert_with_parent(collider, character_handle, &mut bodies);
@@ -110,7 +118,7 @@ pub fn init_world(testbed: &mut Testbed) {
     /*
      * Create a moving platform.
      */
-    let body = RigidBodyBuilder::kinematic_velocity_based().translation(vector![-8.0, 1.5]);
+    let body = RigidBodyBuilder::kinematic_velocity_based().translation(vector![-8.0, 0.0]);
     // .rotation(-0.3);
     let platform_handle = bodies.insert(body);
     let collider = ColliderBuilder::cuboid(2.0, ground_height);
@@ -160,10 +168,34 @@ pub fn init_world(testbed: &mut Testbed) {
         }
     });
 
+    /*
+     * Callback to update the character based on user inputs.
+     */
+    let mut control_mode = CharacterControlMode::Kinematic;
+    let mut controller = KinematicCharacterController {
+        max_slope_climb_angle: impossible_slope_angle - 0.02,
+        min_slope_slide_angle: impossible_slope_angle - 0.02,
+        slide: true,
+        ..Default::default()
+    };
+    let mut pid = PidController::default();
+
+    testbed.add_callback(move |graphics, physics, _, _| {
+        if let Some(graphics) = graphics {
+            character::update_character(
+                graphics,
+                physics,
+                &mut control_mode,
+                &mut controller,
+                &mut pid,
+                character_handle,
+            );
+        }
+    });
+
     /*
      * Set up the testbed.
      */
     testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
-    testbed.set_character_body(character_handle);
     testbed.look_at(point![0.0, 1.0], 100.0);
 }

examples2d/rope_joints2.rs

@@ -1,3 +1,6 @@
+use crate::utils::character;
+use crate::utils::character::CharacterControlMode;
+use rapier2d::control::{KinematicCharacterController, PidController};
 use rapier2d::prelude::*;
 use rapier_testbed2d::Testbed;
 
@@ -54,10 +57,29 @@ pub fn init_world(testbed: &mut Testbed) {
     let joint = RopeJointBuilder::new(2.0).local_anchor2(point![0.0, 0.0]);
     impulse_joints.insert(character_handle, child_handle, joint, true);
 
+    /*
+     * Callback to update the character based on user inputs.
+     */
+    let mut control_mode = CharacterControlMode::Kinematic;
+    let mut controller = KinematicCharacterController::default();
+    let mut pid = PidController::default();
+
+    testbed.add_callback(move |graphics, physics, _, _| {
+        if let Some(graphics) = graphics {
+            character::update_character(
+                graphics,
+                physics,
+                &mut control_mode,
+                &mut controller,
+                &mut pid,
+                character_handle,
+            );
+        }
+    });
+
     /*
      * Set up the testbed.
      */
     testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
-    testbed.set_character_body(character_handle);
     testbed.look_at(point![0.0, 1.0], 100.0);
 }