feat: add urdf example

examples3d/urdf3.rs

@@ -0,0 +1,38 @@
+use rapier3d::prelude::*;
+use rapier_testbed3d::Testbed;
+use rapier_urdf::{RapierRobot, UrdfLoaderOptions};
+
+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();
+
+    /*
+     * Ground
+     */
+    let options = UrdfLoaderOptions {
+        create_colliders_from_visual_shapes: true,
+        create_colliders_from_collision_shapes: false,
+        apply_imported_mass_props: true,
+        make_roots_fixed: true,
+        // rigid_body_blueprint: RigidBodyBuilder::dynamic().gravity_scale(0.0),
+        collider_blueprint: ColliderBuilder::ball(0.0)
+            .density(0.0)
+            .active_collision_types(ActiveCollisionTypes::empty()),
+        ..Default::default()
+    };
+    let (mut robot, _) = RapierRobot::from_file("assets/3d/sample.urdf", options).unwrap();
+
+    // robot.insert_using_impulse_joints(&mut bodies, &mut colliders, &mut impulse_joints);
+    robot.insert_using_multibody_joints(&mut bodies, &mut colliders, &mut multibody_joints);
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
+    testbed.look_at(point![100.0, 100.0, 100.0], Point::origin());
+}