Merge branch 'master' into collider-builder-debug

10 files changed, 416 insertions, 153 deletions

diff --git a/examples3d/all_examples3.rs b/examples3d/all_examples3.rs
index bac826e..3e6398f 100644
--- a/examples3d/all_examples3.rs
+++ b/examples3d/all_examples3.rs
@@ -23,12 +23,15 @@ mod debug_deserialize3;
 mod debug_dynamic_collider_add3;
 mod debug_friction3;
 mod debug_infinite_fall3;
+mod debug_pop3;
 mod debug_prismatic3;
 mod debug_rollback3;
 mod debug_shape_modification3;
+mod debug_thin_cube_on_mesh3;
 mod debug_triangle3;
 mod debug_trimesh3;
 mod domino3;
+mod dynamic_trimesh3;
 mod fountain3;
 mod heightfield3;
 mod joints3;
@@ -39,6 +42,7 @@ mod debug_cube_high_mass_ratio3;
 mod debug_internal_edges3;
 mod debug_long_chain3;
 mod debug_multibody_ang_motor_pos3;
+mod inverse_kinematics3;
 mod joint_motor_position3;
 mod keva3;
 mod locked_rotations3;
@@ -102,8 +106,10 @@ pub fn main() {
         ("Convex polyhedron", convex_polyhedron3::init_world),
         ("Damping", damping3::init_world),
         ("Domino", domino3::init_world),
+        ("Dynamic trimeshes", dynamic_trimesh3::init_world),
         ("Heightfield", heightfield3::init_world),
         ("Impulse Joints", joints3::init_world_with_joints),
+        ("Inverse kinematics", inverse_kinematics3::init_world),
         ("Joint Motor Position", joint_motor_position3::init_world),
         ("Locked rotations", locked_rotations3::init_world),
         ("One-way platforms", one_way_platforms3::init_world),
@@ -124,6 +130,7 @@ pub fn main() {
         ),
         ("(Debug) big colliders", debug_big_colliders3::init_world),
         ("(Debug) boxes", debug_boxes3::init_world),
+        ("(Debug) pop", debug_pop3::init_world),
         (
             "(Debug) dyn. coll. add",
             debug_dynamic_collider_add3::init_world,
@@ -141,6 +148,7 @@ pub fn main() {
         ),
         ("(Debug) triangle", debug_triangle3::init_world),
         ("(Debug) trimesh", debug_trimesh3::init_world),
+        ("(Debug) thin cube", debug_thin_cube_on_mesh3::init_world),
         ("(Debug) cylinder", debug_cylinder3::init_world),
         ("(Debug) infinite fall", debug_infinite_fall3::init_world),
         ("(Debug) prismatic", debug_prismatic3::init_world),
diff --git a/examples3d/character_controller3.rs b/examples3d/character_controller3.rs
index 939cfd1..f031f0a 100644
--- a/examples3d/character_controller3.rs
+++ b/examples3d/character_controller3.rs
@@ -13,21 +13,37 @@ pub fn init_world(testbed: &mut Testbed) {
     /*
      * Ground
      */
+    let scale = 1.0; // Set to a larger value to check if it still works with larger units.
     let ground_size = 5.0;
     let ground_height = 0.1;
 
-    let rigid_body = RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, 0.0]);
+    let rigid_body =
+        RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, 0.0] * scale);
+    let floor_handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(
+        ground_size * scale,
+        ground_height * scale,
+        ground_size * scale,
+    );
+    colliders.insert_with_parent(collider, floor_handle, &mut bodies);
+
+    let rigid_body =
+        RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, -ground_size] * scale); //.rotation(vector![-0.1, 0.0, 0.0]);
     let floor_handle = bodies.insert(rigid_body);
-    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size);
+    let collider = ColliderBuilder::cuboid(
+        ground_size * scale,
+        ground_size * scale,
+        ground_height * scale,
+    );
     colliders.insert_with_parent(collider, floor_handle, &mut bodies);
 
     /*
      * Character we will control manually.
      */
     let rigid_body =
-        RigidBodyBuilder::kinematic_position_based().translation(vector![-3.0, 5.0, 0.0]);
+        RigidBodyBuilder::kinematic_position_based().translation(vector![-3.0, 5.0, 0.0] * scale);
     let character_handle = bodies.insert(rigid_body);
-    let collider = ColliderBuilder::capsule_y(0.3, 0.15); // 0.15, 0.3, 0.15);
+    let collider = ColliderBuilder::capsule_y(0.3 * scale, 0.15 * scale); // 0.15, 0.3, 0.15);
     colliders.insert_with_parent(collider, character_handle, &mut bodies);
 
     /*
@@ -47,9 +63,9 @@ pub fn init_world(testbed: &mut Testbed) {
                 let y = j as f32 * shift + centery;
                 let z = k as f32 * shift + centerx;
 
-                let rigid_body = RigidBodyBuilder::dynamic().translation(vector![x, y, z]);
+                let rigid_body = RigidBodyBuilder::dynamic().translation(vector![x, y, z] * scale);
                 let handle = bodies.insert(rigid_body);
-                let collider = ColliderBuilder::cuboid(rad, rad, rad);
+                let collider = ColliderBuilder::cuboid(rad * scale, rad * scale, rad * scale);
                 colliders.insert_with_parent(collider, handle, &mut bodies);
             }
         }
@@ -64,8 +80,12 @@ pub fn init_world(testbed: &mut Testbed) {
         let x = i as f32 * stair_width / 2.0;
         let y = i as f32 * stair_height * 1.5 + 3.0;
 
-        let collider = ColliderBuilder::cuboid(stair_width / 2.0, stair_height / 2.0, stair_width)
-            .translation(vector![x, y, 0.0]);
+        let collider = ColliderBuilder::cuboid(
+            stair_width / 2.0 * scale,
+            stair_height / 2.0 * scale,
+            stair_width * scale,
+        )
+        .translation(vector![x * scale, y * scale, 0.0]);
         colliders.insert(collider);
     }
 
@@ -74,9 +94,13 @@ pub fn init_world(testbed: &mut Testbed) {
      */
     let slope_angle = 0.2;
     let slope_size = 2.0;
-    let collider = ColliderBuilder::cuboid(slope_size, ground_height, slope_size)
-        .translation(vector![ground_size + slope_size, -ground_height + 0.4, 0.0])
-        .rotation(Vector::z() * slope_angle);
+    let collider = ColliderBuilder::cuboid(
+        slope_size * scale,
+        ground_height * scale,
+        slope_size * scale,
+    )
+    .translation(vector![ground_size + slope_size, -ground_height + 0.4, 0.0] * scale)
+    .rotation(Vector::z() * slope_angle);
     colliders.insert(collider);
 
     /*
@@ -84,22 +108,29 @@ pub fn init_world(testbed: &mut Testbed) {
      */
     let impossible_slope_angle = 0.9;
     let impossible_slope_size = 2.0;
-    let collider = ColliderBuilder::cuboid(slope_size, ground_height, ground_size)
-        .translation(vector![
+    let collider = ColliderBuilder::cuboid(
+        slope_size * scale,
+        ground_height * scale,
+        ground_size * scale,
+    )
+    .translation(
+        vector![
             ground_size + slope_size * 2.0 + impossible_slope_size - 0.9,
             -ground_height + 2.3,
             0.0
-        ])
-        .rotation(Vector::z() * impossible_slope_angle);
+        ] * scale,
+    )
+    .rotation(Vector::z() * impossible_slope_angle);
     colliders.insert(collider);
 
     /*
      * Create a moving platform.
      */
-    let body = RigidBodyBuilder::kinematic_velocity_based().translation(vector![-8.0, 1.5, 0.0]);
+    let body =
+        RigidBodyBuilder::kinematic_velocity_based().translation(vector![-8.0, 1.5, 0.0] * scale);
     // .rotation(-0.3);
     let platform_handle = bodies.insert(body);
-    let collider = ColliderBuilder::cuboid(2.0, ground_height, 2.0);
+    let collider = ColliderBuilder::cuboid(2.0 * scale, ground_height * scale, 2.0 * scale);
     colliders.insert_with_parent(collider, platform_handle, &mut bodies);
 
     /*
@@ -113,18 +144,18 @@ pub fn init_world(testbed: &mut Testbed) {
             + (j as f32 * ground_size.z / (nsubdivs as f32) / 2.0).cos()
     });
 
-    let collider =
-        ColliderBuilder::heightfield(heights, ground_size).translation(vector![-8.0, 5.0, 0.0]);
+    let collider = ColliderBuilder::heightfield(heights, ground_size * scale)
+        .translation(vector![-8.0, 5.0, 0.0] * scale);
     colliders.insert(collider);
 
     /*
      * A tilting dynamic body with a limited joint.
      */
-    let ground = RigidBodyBuilder::fixed().translation(vector![0.0, 5.0, 0.0]);
+    let ground = RigidBodyBuilder::fixed().translation(vector![0.0, 5.0, 0.0] * scale);
     let ground_handle = bodies.insert(ground);
-    let body = RigidBodyBuilder::dynamic().translation(vector![0.0, 5.0, 0.0]);
+    let body = RigidBodyBuilder::dynamic().translation(vector![0.0, 5.0, 0.0] * scale);
     let handle = bodies.insert(body);
-    let collider = ColliderBuilder::cuboid(1.0, 0.1, 2.0);
+    let collider = ColliderBuilder::cuboid(1.0 * scale, 0.1 * scale, 2.0 * scale);
     colliders.insert_with_parent(collider, handle, &mut bodies);
     let joint = RevoluteJointBuilder::new(Vector::z_axis()).limits([-0.3, 0.3]);
     impulse_joints.insert(ground_handle, handle, joint, true);
@@ -137,7 +168,7 @@ pub fn init_world(testbed: &mut Testbed) {
             (run_state.time * 2.0).sin() * 2.0,
             (run_state.time * 5.0).sin() * 1.5,
             0.0
-        ];
+        ] * scale;
         // let angvel = run_state.time.sin() * 0.5;
 
         // Update the velocity-based kinematic body by setting its velocity.
diff --git a/examples3d/convex_decomposition3.rs b/examples3d/convex_decomposition3.rs
index 0863430..eeaa682 100644
--- a/examples3d/convex_decomposition3.rs
+++ b/examples3d/convex_decomposition3.rs
@@ -1,128 +1,5 @@
-use obj::raw::object::Polygon;
-use rapier3d::parry::bounding_volume;
-use rapier3d::prelude::*;
 use rapier_testbed3d::Testbed;
-use std::fs::File;
-use std::io::BufReader;
 
-/*
- * NOTE: The `r` macro is only here to convert from f64 to the `N` scalar type.
- * This simplifies experimentation with various scalar types (f32, fixed-point numbers, etc.)
- */
 pub fn init_world(testbed: &mut Testbed) {
-    /*
-     * World
-     */
-    let mut bodies = RigidBodySet::new();
-    let mut colliders = ColliderSet::new();
-    let impulse_joints = ImpulseJointSet::new();
-    let multibody_joints = MultibodyJointSet::new();
-
-    /*
-     * Ground
-     */
-    let ground_size = 50.0;
-    let ground_height = 0.1;
-
-    let rigid_body = RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, 0.0]);
-    let handle = bodies.insert(rigid_body);
-    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size);
-    colliders.insert_with_parent(collider, handle, &mut bodies);
-
-    /*
-     * Create the convex decompositions.
-     */
-    let geoms = models();
-    let ngeoms = geoms.len();
-    let width = (ngeoms as f32).sqrt() as usize;
-    let num_duplications = 4;
-    let shift = 5.0f32;
-
-    for (igeom, obj_path) in geoms.into_iter().enumerate() {
-        let deltas = Isometry::identity();
-
-        let mut shapes = Vec::new();
-        println!("Parsing and decomposing: {}", obj_path);
-        let input = BufReader::new(File::open(obj_path).unwrap());
-
-        if let Ok(model) = obj::raw::parse_obj(input) {
-            let mut vertices: Vec<_> = model
-                .positions
-                .iter()
-                .map(|v| point![v.0, v.1, v.2])
-                .collect();
-            let indices: Vec<_> = model
-                .polygons
-                .into_iter()
-                .flat_map(|p| match p {
-                    Polygon::P(idx) => idx.into_iter(),
-                    Polygon::PT(idx) => Vec::from_iter(idx.into_iter().map(|i| i.0)).into_iter(),
-                    Polygon::PN(idx) => Vec::from_iter(idx.into_iter().map(|i| i.0)).into_iter(),
-                    Polygon::PTN(idx) => Vec::from_iter(idx.into_iter().map(|i| i.0)).into_iter(),
-                })
-                .collect();
-
-            // Compute the size of the model, to scale it and have similar size for everything.
-            let aabb = bounding_volume::details::point_cloud_aabb(&deltas, &vertices);
-            let center = aabb.center();
-            let diag = (aabb.maxs - aabb.mins).norm();
-
-            vertices
-                .iter_mut()
-                .for_each(|p| *p = (*p - center.coords) * 6.0 / diag);
-
-            let indices: Vec<_> = indices
-                .chunks(3)
-                .map(|idx| [idx[0] as u32, idx[1] as u32, idx[2] as u32])
-                .collect();
-
-            let decomposed_shape = SharedShape::convex_decomposition(&vertices, &indices);
-            shapes.push(decomposed_shape);
-
-            // let compound = SharedShape::compound(compound_parts);
-
-            for k in 1..num_duplications + 1 {
-                let x = (igeom % width) as f32 * shift;
-                let y = (igeom / width) as f32 * shift + 4.0;
-                let z = k as f32 * shift;
-
-                let body = RigidBodyBuilder::dynamic().translation(vector![x, y, z]);
-                let handle = bodies.insert(body);
-
-                for shape in &shapes {
-                    let collider = ColliderBuilder::new(shape.clone());
-                    colliders.insert_with_parent(collider, handle, &mut bodies);
-                }
-            }
-        }
-    }
-
-    /*
-     * 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());
-}
-
-fn models() -> Vec<String> {
-    vec![
-        "assets/3d/camel_decimated.obj".to_string(),
-        "assets/3d/chair.obj".to_string(),
-        "assets/3d/cup_decimated.obj".to_string(),
-        "assets/3d/dilo_decimated.obj".to_string(),
-        "assets/3d/feline_decimated.obj".to_string(),
-        "assets/3d/genus3_decimated.obj".to_string(),
-        "assets/3d/hand2_decimated.obj".to_string(),
-        "assets/3d/hand_decimated.obj".to_string(),
-        "assets/3d/hornbug.obj".to_string(),
-        "assets/3d/octopus_decimated.obj".to_string(),
-        "assets/3d/rabbit_decimated.obj".to_string(),
-        // "assets/3d/rust_logo.obj".to_string(),
-        "assets/3d/rust_logo_simplified.obj".to_string(),
-        "assets/3d/screwdriver_decimated.obj".to_string(),
-        "assets/3d/table.obj".to_string(),
-        "assets/3d/tstTorusModel.obj".to_string(),
-        // "assets/3d/tstTorusModel2.obj".to_string(),
-        // "assets/3d/tstTorusModel3.obj".to_string(),
-    ]
+    crate::dynamic_trimesh3::do_init_world(testbed, true);
 }
diff --git a/examples3d/debug_deserialize3.rs b/examples3d/debug_deserialize3.rs
index b8b79fb..0762b4d 100644
--- a/examples3d/debug_deserialize3.rs
+++ b/examples3d/debug_deserialize3.rs
@@ -6,7 +6,7 @@ struct PhysicsState {
     pub gravity: Vector<f32>,
     pub integration_parameters: IntegrationParameters,
     pub islands: IslandManager,
-    pub broad_phase: BroadPhase,
+    pub broad_phase: DefaultBroadPhase,
     pub narrow_phase: NarrowPhase,
     pub bodies: RigidBodySet,
     pub colliders: ColliderSet,
diff --git a/examples3d/debug_internal_edges3.rs b/examples3d/debug_internal_edges3.rs
index 7112fb0..86de1bd 100644
--- a/examples3d/debug_internal_edges3.rs
+++ b/examples3d/debug_internal_edges3.rs
@@ -11,7 +11,8 @@ pub fn init_world(testbed: &mut Testbed) {
     let multibody_joints = MultibodyJointSet::new();
 
     let heights = DMatrix::zeros(100, 100);
-    let heightfield = HeightField::new(heights, vector![60.0, 1.0, 60.0]);
+    let heightfield =
+        HeightField::with_flags(heights, vector![60.0, 1.0, 60.0], HeightFieldFlags::all());
     let rotation = vector![0.0, 0.0, 0.0]; // vector![-0.1, 0.0, 0.0];
     colliders
         .insert(ColliderBuilder::new(SharedShape::new(heightfield.clone())).rotation(rotation));
diff --git a/examples3d/debug_pop3.rs b/examples3d/debug_pop3.rs
new file mode 100644
index 0000000..93d58e0
--- /dev/null
+++ b/examples3d/debug_pop3.rs
@@ -0,0 +1,42 @@
+use rapier3d::prelude::*;
+use rapier_testbed3d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let impulse_joints = ImpulseJointSet::new();
+    let multibody_joints = MultibodyJointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 10.0;
+    let ground_height = 10.0;
+
+    for _ in 0..1 {
+        let rigid_body = RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, 0.0]);
+        let handle = bodies.insert(rigid_body);
+        let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size);
+        colliders.insert_with_parent(collider, handle, &mut bodies);
+    }
+
+    // Build the dynamic box rigid body.
+    for _ in 0..1 {
+        let rigid_body = RigidBodyBuilder::dynamic()
+            // .translation(vector![0.0, 0.1, 0.0])
+            // .rotation(vector![0.8, 0.2, 0.1])
+            .can_sleep(false);
+        let handle = bodies.insert(rigid_body);
+        let collider = ColliderBuilder::cuboid(1.0, 1.0, 1.0);
+        colliders.insert_with_parent(collider.clone(), handle, &mut bodies);
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
+    testbed.look_at(point![10.0, 10.0, 10.0], Point::origin());
+}
diff --git a/examples3d/debug_thin_cube_on_mesh3.rs b/examples3d/debug_thin_cube_on_mesh3.rs
new file mode 100644
index 0000000..4ad557a
--- /dev/null
+++ b/examples3d/debug_thin_cube_on_mesh3.rs
@@ -0,0 +1,56 @@
+use rapier3d::prelude::*;
+use rapier_testbed3d::Testbed;
+
+// This shows a bug when a cylinder is in contact with a very large
+// but very thin cuboid. In this case the EPA returns an incorrect
+// contact normal, resulting in the cylinder falling through the floor.
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let impulse_joints = ImpulseJointSet::new();
+    let multibody_joints = MultibodyJointSet::new();
+
+    /*
+     * Ground
+     */
+    // let vertices = vec![
+    //     point![-50.0, 0.0, -50.0],
+    //     point![-50.0, 0.0, 50.0],
+    //     point![50.0, 0.0, 50.0],
+    //     point![50.0, 0.0, -50.0],
+    // ];
+    // let indices = vec![[0, 1, 2], [0, 2, 3]];
+    //
+    // let collider = ColliderBuilder::trimesh_with_flags(vertices, indices, TriMeshFlags::all());
+    // colliders.insert(collider);
+
+    let heights = DMatrix::repeat(2, 2, 0.0);
+    let collider = ColliderBuilder::heightfield_with_flags(
+        heights,
+        Vector::new(50.0, 1.0, 50.0),
+        HeightFieldFlags::FIX_INTERNAL_EDGES,
+    );
+    colliders.insert(collider);
+
+    /*
+     * Create the cubes
+     */
+    // Build the rigid body.
+    let rigid_body = RigidBodyBuilder::dynamic()
+        .translation(vector![0.0, 5.0, 0.0])
+        .rotation(vector![0.5, 0.0, 0.5])
+        .linvel(vector![0.0, -100.0, 0.0])
+        .soft_ccd_prediction(10.0);
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(5.0, 0.015, 5.0);
+    colliders.insert_with_parent(collider, handle, &mut bodies);
+
+    /*
+     * 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());
+}
diff --git a/examples3d/dynamic_trimesh3.rs b/examples3d/dynamic_trimesh3.rs
new file mode 100644
index 0000000..0a82476
--- /dev/null
+++ b/examples3d/dynamic_trimesh3.rs
@@ -0,0 +1,145 @@
+use obj::raw::object::Polygon;
+use rapier3d::parry::bounding_volume;
+use rapier3d::prelude::*;
+use rapier_testbed3d::Testbed;
+use std::fs::File;
+use std::io::BufReader;
+
+pub fn init_world(testbed: &mut Testbed) {
+    do_init_world(testbed, false);
+}
+
+pub fn do_init_world(testbed: &mut Testbed, use_convex_decomposition: bool) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let impulse_joints = ImpulseJointSet::new();
+    let multibody_joints = MultibodyJointSet::new();
+
+    /*
+     * Ground
+     */
+    //// OPTION 1: floor made of a single big box.
+    // let ground_size = 50.0;
+    // let ground_height = 0.1;
+    // let rigid_body = RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, 0.0]);
+    // let handle = bodies.insert(rigid_body);
+    // let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size);
+    // colliders.insert_with_parent(collider, handle, &mut bodies);
+
+    //// OPTION 2: floor made of a wavy mesh.
+    let nsubdivs = 100;
+    let heights = DMatrix::from_fn(nsubdivs + 1, nsubdivs + 1, |i, j| {
+        -(i as f32 * 40.0 / (nsubdivs as f32) / 2.0).cos()
+            - (j as f32 * 40.0 / (nsubdivs as f32) / 2.0).cos()
+    });
+    let heightfield = HeightField::new(heights, vector![100.0, 2.0, 100.0]);
+    let mut trimesh = TriMesh::from(heightfield);
+    let _ = trimesh.set_flags(TriMeshFlags::FIX_INTERNAL_EDGES);
+    colliders.insert(ColliderBuilder::new(SharedShape::new(trimesh.clone())));
+
+    /*
+     * Create the convex decompositions.
+     */
+    let geoms = models();
+    let ngeoms = geoms.len();
+    let width = (ngeoms as f32).sqrt() as usize;
+    let num_duplications = 4;
+    let shift_y = 8.0f32;
+    let shift_xz = 9.0f32;
+
+    for (igeom, obj_path) in geoms.into_iter().enumerate() {
+        let deltas = Isometry::identity();
+
+        let mut shapes = Vec::new();
+        println!("Parsing and decomposing: {}", obj_path);
+        let input = BufReader::new(File::open(obj_path).unwrap());
+
+        if let Ok(model) = obj::raw::parse_obj(input) {
+            let mut vertices: Vec<_> = model
+                .positions
+                .iter()
+                .map(|v| point![v.0, v.1, v.2])
+                .collect();
+            let indices: Vec<_> = model
+                .polygons
+                .into_iter()
+                .flat_map(|p| match p {
+                    Polygon::P(idx) => idx.into_iter(),
+                    Polygon::PT(idx) => Vec::from_iter(idx.into_iter().map(|i| i.0)).into_iter(),
+                    Polygon::PN(idx) => Vec::from_iter(idx.into_iter().map(|i| i.0)).into_iter(),
+                    Polygon::PTN(idx) => Vec::from_iter(idx.into_iter().map(|i| i.0)).into_iter(),
+                })
+                .collect();
+
+            // Compute the size of the model, to scale it and have similar size for everything.
+            let aabb = bounding_volume::details::point_cloud_aabb(&deltas, &vertices);
+            let center = aabb.center();
+            let diag = (aabb.maxs - aabb.mins).norm();
+
+            vertices
+                .iter_mut()
+                .for_each(|p| *p = (*p - center.coords) * 10.0 / diag);
+
+            let indices: Vec<_> = indices
+                .chunks(3)
+                .map(|idx| [idx[0] as u32, idx[1] as u32, idx[2] as u32])
+                .collect();
+
+            let decomposed_shape = if use_convex_decomposition {
+                SharedShape::convex_decomposition(&vertices, &indices)
+            } else {
+                // SharedShape::trimesh(vertices, indices)
+                SharedShape::trimesh_with_flags(vertices, indices, TriMeshFlags::FIX_INTERNAL_EDGES)
+            };
+            shapes.push(decomposed_shape);
+
+            // let compound = SharedShape::compound(compound_parts);
+
+            for k in 1..num_duplications + 1 {
+                let x =
+                    (igeom % width) as f32 * shift_xz - num_duplications as f32 * shift_xz / 2.0;
+                let y = (igeom / width) as f32 * shift_y + 7.0;
+                let z = k as f32 * shift_xz - num_duplications as f32 * shift_xz / 2.0;
+
+                let body = RigidBodyBuilder::dynamic().translation(vector![x, y, z]);
+                let handle = bodies.insert(body);
+
+                for shape in &shapes {
+                    let collider = ColliderBuilder::new(shape.clone()).contact_skin(0.1);
+                    colliders.insert_with_parent(collider, handle, &mut bodies);
+                }
+            }
+        }
+    }
+
+    /*
+     * 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());
+}
+
+fn models() -> Vec<String> {
+    vec![
+        "assets/3d/camel_decimated.obj".to_string(),
+        "assets/3d/chair.obj".to_string(),
+        "assets/3d/cup_decimated.obj".to_string(),
+        "assets/3d/dilo_decimated.obj".to_string(),
+        "assets/3d/tstTorusModel2.obj".to_string(),
+        "assets/3d/feline_decimated.obj".to_string(),
+        "assets/3d/genus3_decimated.obj".to_string(),
+        // "assets/3d/hand2_decimated.obj".to_string(),
+        // "assets/3d/hand_decimated.obj".to_string(),
+        "assets/3d/hornbug.obj".to_string(),
+        "assets/3d/tstTorusModel.obj".to_string(),
+        "assets/3d/octopus_decimated.obj".to_string(),
+        "assets/3d/rabbit_decimated.obj".to_string(),
+        "assets/3d/rust_logo_simplified.obj".to_string(),
+        "assets/3d/screwdriver_decimated.obj".to_string(),
+        "assets/3d/table.obj".to_string(),
+        "assets/3d/tstTorusModel3.obj".to_string(),
+    ]
+}
diff --git a/examples3d/inverse_kinematics3.rs b/examples3d/inverse_kinematics3.rs
new file mode 100644
index 0000000..7905ae0
--- /dev/null
+++ b/examples3d/inverse_kinematics3.rs
@@ -0,0 +1,103 @@
+use rapier3d::prelude::*;
+use rapier_testbed3d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let impulse_joints = ImpulseJointSet::new();
+    let mut multibody_joints = MultibodyJointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 0.2;
+    let ground_height = 0.01;
+
+    let rigid_body = RigidBodyBuilder::fixed().translation(vector![0.0, -ground_height, 0.0]);
+    let floor_handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size);
+    colliders.insert_with_parent(collider, floor_handle, &mut bodies);
+
+    /*
+     * Setup groups
+     */
+    let num_segments = 10;
+    let body = RigidBodyBuilder::fixed();
+    let mut last_body = bodies.insert(body);
+    let mut last_link = MultibodyJointHandle::invalid();
+
+    for i in 0..num_segments {
+        let size = 1.0 / num_segments as f32;
+        let body = RigidBodyBuilder::dynamic().can_sleep(false);
+        let new_body = bodies.insert(body);
+        // NOTE: we add a sensor collider just to make the destbed draw a rectangle to make
+        //       the demo look nicer. IK could be used without cuboid.
+        let collider = ColliderBuilder::cuboid(size / 8.0, size / 2.0, size / 8.0)
+            .density(0.0)
+            .sensor(true);
+        colliders.insert_with_parent(collider, new_body, &mut bodies);
+
+        let link_ab = SphericalJointBuilder::new()
+            .local_anchor1(point![0.0, size / 2.0 * (i != 0) as usize as f32, 0.0])
+            .local_anchor2(point![0.0, -size / 2.0, 0.0])
+            .build()
+            .data;
+
+        last_link = multibody_joints
+            .insert(last_body, new_body, link_ab, true)
+            .unwrap();
+
+        last_body = new_body;
+    }
+
+    let mut displacements = DVector::zeros(0);
+
+    testbed.add_callback(move |graphics, physics, _, _| {
+        let Some(graphics) = graphics else { return };
+        if let Some((multibody, link_id)) = physics.multibody_joints.get_mut(last_link) {
+            // Ensure our displacement vector has the right number of elements.
+            if displacements.nrows() < multibody.ndofs() {
+                displacements = DVector::zeros(multibody.ndofs());
+            } else {
+                displacements.fill(0.0);
+            }
+
+            let Some(mouse_ray) = graphics.mouse().ray else {
+                return;
+            };
+
+            // Cast a ray on a plane aligned with the camera passing through the origin.
+            let halfspace = HalfSpace {
+                normal: -UnitVector::new_normalize(graphics.camera_fwd_dir()),
+            };
+            let mouse_ray = Ray::new(mouse_ray.0, mouse_ray.1);
+            let Some(hit) = halfspace.cast_local_ray(&mouse_ray, f32::MAX, false) else {
+                return;
+            };
+            let target_point = mouse_ray.point_at(hit);
+
+            let options = InverseKinematicsOption {
+                constrained_axes: JointAxesMask::LIN_AXES,
+                ..Default::default()
+            };
+
+            multibody.inverse_kinematics(
+                &physics.bodies,
+                link_id,
+                &options,
+                &Isometry::from(target_point),
+                &mut displacements,
+            );
+            multibody.apply_displacements(displacements.as_slice());
+        }
+    });
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, impulse_joints, multibody_joints);
+    testbed.look_at(point![0.0, 0.5, 2.5], point![0.0, 0.5, 0.0]);
+}
diff --git a/examples3d/vehicle_joints3.rs b/examples3d/vehicle_joints3.rs
index ddd672c..5eba608 100644
--- a/examples3d/vehicle_joints3.rs
+++ b/examples3d/vehicle_joints3.rs
@@ -138,16 +138,16 @@ pub fn init_world(testbed: &mut Testbed) {
 
         for key in gfx.keys().get_pressed() {
             match *key {
-                KeyCode::Right => {
+                KeyCode::ArrowRight => {
                     steering = -1.0;
                 }
-                KeyCode::Left => {
+                KeyCode::ArrowLeft => {
                     steering = 1.0;
                 }
-                KeyCode::Up => {
+                KeyCode::ArrowUp => {
                     thrust = -drive_strength;
                 }
-                KeyCode::Down => {
+                KeyCode::ArrowDown => {
                     thrust = drive_strength;
                 }
                 KeyCode::ShiftRight => {