Implement multibody joints and the new solver

examples3d/debug_articulations3.rs

@@ -0,0 +1,98 @@
+use rapier3d::prelude::*;
+use rapier_testbed3d::Testbed;
+
+fn create_ball_articulations(
+    bodies: &mut RigidBodySet,
+    colliders: &mut ColliderSet,
+    impulse_joints: &mut ImpulseJointSet,
+    multibody_joints: &mut MultibodyJointSet,
+    num: usize,
+) {
+    let rad = 0.4;
+    let shift = 1.0;
+
+    let mut body_handles = Vec::new();
+
+    for k in 0..num {
+        for i in 0..num {
+            let fk = k as f32;
+            let fi = i as f32;
+
+            let status = if i == 0 {
+                // && (k % 4 == 0 || k == num - 1) {
+                RigidBodyType::Static
+            } else {
+                RigidBodyType::Dynamic
+            };
+
+            let rigid_body = RigidBodyBuilder::new(status)
+                .translation(vector![fk * shift, 0.0, fi * shift * 2.0])
+                .build();
+            let child_handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::capsule_z(rad * 1.25, rad).build();
+            colliders.insert_with_parent(collider, child_handle, bodies);
+
+            // Vertical multibody_joint.
+            if i > 0 {
+                let parent_handle = *body_handles.last().unwrap();
+                let joint = SphericalJoint::new().local_anchor2(point![0.0, 0.0, -shift * 2.0]);
+                multibody_joints.insert(parent_handle, child_handle, joint);
+            }
+
+            // Horizontal multibody_joint.
+            if k > 0 && i > 0 {
+                let parent_index = body_handles.len() - num;
+                let parent_handle = body_handles[parent_index];
+                let joint = SphericalJoint::new().local_anchor2(point![-shift, 0.0, 0.0]);
+                // let joint =
+                //     PrismaticJoint::new(Vector::y_axis()).local_anchor2(point![-shift, 0.0, 0.0]);
+                // let joint = FixedJoint::new().local_anchor2(point![-shift, 0.0, 0.0]);
+                // let joint =
+                //     RevoluteJoint::new(Vector::x_axis()).local_anchor2(point![-shift, 0.0, 0.0]);
+                impulse_joints.insert(parent_handle, child_handle, joint);
+            }
+
+            body_handles.push(child_handle);
+        }
+    }
+}
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let mut impulse_joints = ImpulseJointSet::new();
+    let mut multibody_joints = MultibodyJointSet::new();
+
+    let rigid_body = RigidBodyBuilder::new_dynamic().build();
+    let collider = ColliderBuilder::cuboid(30.0, 0.01, 30.0) // Vector::y_axis())
+        .translation(vector![0.0, -3.0, 0.0])
+        .rotation(vector![0.1, 0.0, 0.1])
+        .build();
+    let handle = bodies.insert(rigid_body);
+    colliders.insert_with_parent(collider, handle, &mut bodies);
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let collider = ColliderBuilder::cuboid(30.0, 0.01, 30.0) // Vector::y_axis())
+        .translation(vector![0.0, -3.02, 0.0])
+        .rotation(vector![0.1, 0.0, 0.1])
+        .build();
+    let handle = bodies.insert(rigid_body);
+    colliders.insert_with_parent(collider, handle, &mut bodies);
+
+    create_ball_articulations(
+        &mut bodies,
+        &mut colliders,
+        &mut impulse_joints,
+        &mut multibody_joints,
+        15,
+    );
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
+    testbed.look_at(point![15.0, 5.0, 42.0], point![13.0, 1.0, 1.0]);
+}