Move benchmark demos into their own directory.

Cargo.toml

@@ -1,12 +1,12 @@
 [workspace]
 members = [ "build/rapier2d", "build/rapier_testbed2d", "examples2d",
-            "build/rapier3d", "build/rapier_testbed3d", "examples3d" ]
+            "build/rapier3d", "build/rapier_testbed3d", "examples3d", "benchmarks3d" ]
 
 [patch.crates-io]
 #wrapped2d = { git = "https://github.com/Bastacyclop/rust_box2d.git" }
 
 [profile.release]
-debug = false
+debug = true
 codegen-units = 1
 #opt-level = 1
 #lto = true

benchmarks3d/Cargo.toml

@@ -0,0 +1,27 @@
+[package]
+name    = "rapier-benchmarks-3d"
+version = "0.1.0"
+authors = [ "Sébastien Crozet <developer@crozet.re>" ]
+edition = "2018"
+
+[features]
+parallel = [ "rapier3d/parallel", "rapier_testbed3d/parallel" ]
+simd-stable = [ "rapier3d/simd-stable" ]
+simd-nightly = [ "rapier3d/simd-nightly" ]
+other-backends = [ "rapier_testbed3d/other-backends" ]
+enhanced-determinism = [ "rapier3d/enhanced-determinism" ]
+
+[dependencies]
+rand       = "0.7"
+Inflector  = "0.11"
+nalgebra = "0.22"
+
+[dependencies.rapier_testbed3d]
+path = "../build/rapier_testbed3d"
+
+[dependencies.rapier3d]
+path = "../build/rapier3d"
+
+[[bin]]
+name = "all_benchmarks3"
+path = "all_benchmarks3.rs"

benchmarks3d/all_benchmarks3.rs

@@ -0,0 +1,91 @@
+#![allow(dead_code)]
+
+extern crate nalgebra as na;
+
+#[cfg(target_arch = "wasm32")]
+use wasm_bindgen::prelude::*;
+
+use inflector::Inflector;
+
+use rapier_testbed3d::Testbed;
+use std::cmp::Ordering;
+
+mod balls3;
+mod boxes3;
+mod capsules3;
+mod compound3;
+mod heightfield3;
+mod joint_ball3;
+mod joint_fixed3;
+mod joint_prismatic3;
+mod joint_revolute3;
+mod keva3;
+mod pyramid3;
+mod stacks3;
+mod trimesh3;
+
+enum Command {
+    Run(String),
+    List,
+    RunAll,
+}
+
+fn parse_command_line() -> Command {
+    let mut args = std::env::args();
+
+    while let Some(arg) = args.next() {
+        if &arg[..] == "--example" {
+            return Command::Run(args.next().unwrap_or(String::new()));
+        } else if &arg[..] == "--list" {
+            return Command::List;
+        }
+    }
+
+    Command::RunAll
+}
+
+pub fn main() {
+    let command = parse_command_line();
+
+    let mut builders: Vec<(_, fn(&mut Testbed))> = vec![
+        ("Balls", balls3::init_world),
+        ("Boxes", boxes3::init_world),
+        ("Capsules", capsules3::init_world),
+        ("Compound", compound3::init_world),
+        ("Heightfield", heightfield3::init_world),
+        ("Stacks", stacks3::init_world),
+        ("Pyramid", pyramid3::init_world),
+        ("Trimesh", trimesh3::init_world),
+        ("Joint ball", joint_ball3::init_world),
+        ("Joint fixed", joint_fixed3::init_world),
+        ("Joint revolute", joint_revolute3::init_world),
+        ("Joint prismatic", joint_prismatic3::init_world),
+        ("Keva tower", keva3::init_world),
+    ];
+
+    // Lexicographic sort, with stress tests moved at the end of the list.
+    builders.sort_by(|a, b| match (a.0.starts_with("("), b.0.starts_with("(")) {
+        (true, true) | (false, false) => a.0.cmp(b.0),
+        (true, false) => Ordering::Greater,
+        (false, true) => Ordering::Less,
+    });
+
+    match command {
+        Command::Run(demo) => {
+            if let Some(i) = builders
+                .iter()
+                .position(|builder| builder.0.to_camel_case().as_str() == demo.as_str())
+            {
+                Testbed::from_builders(0, vec![builders[i]]).run()
+            } else {
+                eprintln!("Invalid example to run provided: '{}'", demo);
+            }
+        }
+        Command::RunAll => Testbed::from_builders(0, builders).run(),
+        Command::List => {
+            for builder in &builders {
+                println!("{}", builder.0.to_camel_case())
+            }
+        }
+    }
+}

benchmarks3d/balls3.rs

@@ -0,0 +1,58 @@
+use na::Point3;
+use rapier3d::dynamics::{BodyStatus, JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed3d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Create the balls
+     */
+    let num = 20;
+    let rad = 1.0;
+
+    let shift = rad * 2.0 + 1.0;
+    let centerx = shift * (num as f32) / 2.0;
+    let centery = shift / 2.0;
+    let centerz = shift * (num as f32) / 2.0;
+
+    for i in 0..num {
+        for j in 0usize..num {
+            for k in 0..num {
+                let x = i as f32 * shift - centerx;
+                let y = j as f32 * shift + centery;
+                let z = k as f32 * shift - centerz;
+
+                let status = if j == 0 {
+                    BodyStatus::Static
+                } else {
+                    BodyStatus::Dynamic
+                };
+                let density = 0.477;
+
+                // Build the rigid body.
+                let rigid_body = RigidBodyBuilder::new(status).translation(x, y, z).build();
+                let handle = bodies.insert(rigid_body);
+                let collider = ColliderBuilder::ball(rad).density(density).build();
+                colliders.insert(collider, handle, &mut bodies);
+            }
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Balls", init_world)]);
+    testbed.run()
+}

benchmarks3d/boxes3.rs

@@ -47,7 +47,7 @@ pub fn init_world(testbed: &mut Testbed) {
                 // Build the rigid body.
                 let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
                 let handle = bodies.insert(rigid_body);
-                let collider = ColliderBuilder::cuboid(rad, rad, rad).density(1.0).build();
+                let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
                 colliders.insert(collider, handle, &mut bodies);
             }
         }

benchmarks3d/capsules3.rs

@@ -48,7 +48,7 @@ pub fn init_world(testbed: &mut Testbed) {
                 // Build the rigid body.
                 let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
                 let handle = bodies.insert(rigid_body);
-                let collider = ColliderBuilder::capsule_y(rad, rad).density(1.0).build();
+                let collider = ColliderBuilder::capsule_y(rad, rad).build();
                 colliders.insert(collider, handle, &mut bodies);
             }
         }

benchmarks3d/compound3.rs

@@ -0,0 +1,76 @@
+use na::Point3;
+use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed3d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 200.1;
+    let ground_height = 0.1;
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .translation(0.0, -ground_height, 0.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 8;
+    let rad = 0.2;
+
+    let shift = rad * 4.0 + rad;
+    let centerx = shift * (num / 2) as f32;
+    let centery = shift / 2.0;
+    let centerz = shift * (num / 2) as f32;
+
+    let mut offset = -(num as f32) * (rad * 2.0 + rad) * 0.5;
+
+    for j in 0usize..25 {
+        for i in 0..num {
+            for k in 0usize..num {
+                let x = i as f32 * shift * 5.0 - centerx + offset;
+                let y = j as f32 * (shift * 5.0) + centery + 3.0;
+                let z = k as f32 * shift * 2.0 - centerz + offset;
+
+                // Build the rigid body.
+                let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
+                let handle = bodies.insert(rigid_body);
+                let collider1 = ColliderBuilder::cuboid(rad * 10.0, rad, rad).build();
+                let collider2 = ColliderBuilder::cuboid(rad, rad * 10.0, rad)
+                    .translation(rad * 10.0, rad * 10.0, 0.0)
+                    .build();
+                let collider3 = ColliderBuilder::cuboid(rad, rad * 10.0, rad)
+                    .translation(-rad * 10.0, rad * 10.0, 0.0)
+                    .build();
+                colliders.insert(collider1, handle, &mut bodies);
+                colliders.insert(collider2, handle, &mut bodies);
+                colliders.insert(collider3, handle, &mut bodies);
+            }
+        }
+
+        offset -= 0.05 * rad * (num as f32 - 1.0);
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
+    testbed.run()
+}

benchmarks3d/heightfield3.rs

@@ -0,0 +1,78 @@
+use na::{DMatrix, Point3, Vector3};
+use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed3d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = Vector3::new(200.0, 1.0, 200.0);
+    let nsubdivs = 20;
+
+    let heights = DMatrix::from_fn(nsubdivs + 1, nsubdivs + 1, |i, j| {
+        if i == 0 || i == nsubdivs || j == 0 || j == nsubdivs {
+            10.0
+        } else {
+            let x = i as f32 * ground_size.x / (nsubdivs as f32);
+            let z = j as f32 * ground_size.z / (nsubdivs as f32);
+            x.sin() + z.cos()
+        }
+    });
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::heightfield(heights, ground_size).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 8;
+    let rad = 1.0;
+
+    let shift = rad * 2.0 + rad;
+    let centerx = shift * (num / 2) as f32;
+    let centery = shift / 2.0;
+    let centerz = shift * (num / 2) as f32;
+
+    for j in 0usize..47 {
+        for i in 0..num {
+            for k in 0usize..num {
+                let x = i as f32 * shift - centerx;
+                let y = j as f32 * shift + centery + 3.0;
+                let z = k as f32 * shift - centerz;
+
+                // Build the rigid body.
+                let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
+                let handle = bodies.insert(rigid_body);
+
+                if j % 2 == 0 {
+                    let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
+                    colliders.insert(collider, handle, &mut bodies);
+                } else {
+                    let collider = ColliderBuilder::ball(rad).build();
+                    colliders.insert(collider, handle, &mut bodies);
+                }
+            }
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
+    testbed.run()
+}

benchmarks3d/joint_ball3.rs

@@ -32,7 +32,7 @@ pub fn init_world(testbed: &mut Testbed) {
                 .translation(fk * shift, 0.0, fi * shift)
                 .build();
             let child_handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            let collider = ColliderBuilder::ball(rad).build();
             colliders.insert(collider, child_handle, &mut bodies);
 
             // Vertical joint.

benchmarks3d/joint_fixed3.rs

@@ -45,7 +45,7 @@ pub fn init_world(testbed: &mut Testbed) {
                             .translation(x + fk * shift, y, z + fi * shift)
                             .build();
                         let child_handle = bodies.insert(rigid_body);
-                        let collider = ColliderBuilder::ball(rad).density(1.0).build();
+                        let collider = ColliderBuilder::ball(rad).build();
                         colliders.insert(collider, child_handle, &mut bodies);
 
                         // Vertical joint.

benchmarks3d/keva3.rs

@@ -48,9 +48,7 @@ pub fn build_block(
                     )
                     .build();
                 let handle = bodies.insert(rigid_body);
-                let collider = ColliderBuilder::cuboid(dim.x, dim.y, dim.z)
-                    .density(1.0)
-                    .build();
+                let collider = ColliderBuilder::cuboid(dim.x, dim.y, dim.z).build();
                 colliders.insert(collider, handle, bodies);
 
                 testbed.set_body_color(handle, color0);
@@ -73,9 +71,7 @@ pub fn build_block(
                 )
                 .build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(dim.x, dim.y, dim.z)
-                .density(1.0)
-                .build();
+            let collider = ColliderBuilder::cuboid(dim.x, dim.y, dim.z).build();
             colliders.insert(collider, handle, bodies);
             testbed.set_body_color(handle, color0);
             std::mem::swap(&mut color0, &mut color1);

benchmarks3d/pyramid3.rs

@@ -28,9 +28,7 @@ fn create_pyramid(
                 let rigid_body_handle = bodies.insert(rigid_body);
 
                 let collider =
-                    ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z)
-                        .density(1.0)
-                        .build();
+                    ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z).build();
                 colliders.insert(collider, rigid_body_handle, bodies);
             }
         }

benchmarks3d/stacks3.rs

@@ -0,0 +1,191 @@
+use na::{Point3, Translation3, UnitQuaternion, Vector3};
+use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed3d::Testbed;
+
+fn create_tower_circle(
+    bodies: &mut RigidBodySet,
+    colliders: &mut ColliderSet,
+    offset: Vector3<f32>,
+    stack_height: usize,
+    nsubdivs: usize,
+    half_extents: Vector3<f32>,
+) {
+    let ang_step = std::f32::consts::PI * 2.0 / nsubdivs as f32;
+    let radius = 1.3 * nsubdivs as f32 * half_extents.x / std::f32::consts::PI;
+
+    let shift = half_extents * 2.0;
+    for i in 0usize..stack_height {
+        for j in 0..nsubdivs {
+            let fj = j as f32;
+            let fi = i as f32;
+            let y = fi * shift.y;
+            let pos = Translation3::from(offset)
+                * UnitQuaternion::new(Vector3::y() * (fi / 2.0 + fj) * ang_step)
+                * Translation3::new(0.0, y, radius);
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic().position(pos).build();
+            let handle = bodies.insert(rigid_body);
+            let collider =
+                ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z).build();
+            colliders.insert(collider, handle, bodies);
+        }
+    }
+}
+
+fn create_wall(
+    bodies: &mut RigidBodySet,
+    colliders: &mut ColliderSet,
+    offset: Vector3<f32>,
+    stack_height: usize,
+    half_extents: Vector3<f32>,
+) {
+    let shift = half_extents * 2.0;
+    for i in 0usize..stack_height {
+        for j in i..stack_height {
+            let fj = j as f32;
+            let fi = i as f32;
+            let x = offset.x;
+            let y = fi * shift.y + offset.y;
+            let z = (fi * shift.z / 2.0) + (fj - fi) * shift.z + offset.z
+                - stack_height as f32 * half_extents.z;
+
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
+            let handle = bodies.insert(rigid_body);
+            let collider =
+                ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z).build();
+            colliders.insert(collider, handle, bodies);
+        }
+    }
+}
+
+fn create_pyramid(
+    bodies: &mut RigidBodySet,
+    colliders: &mut ColliderSet,
+    offset: Vector3<f32>,
+    stack_height: usize,
+    half_extents: Vector3<f32>,
+) {
+    let shift = half_extents * 2.0;
+
+    for i in 0usize..stack_height {
+        for j in i..stack_height {
+            for k in i..stack_height {
+                let fi = i as f32;
+                let fj = j as f32;
+                let fk = k as f32;
+                let x = (fi * shift.x / 2.0) + (fk - fi) * shift.x + offset.x
+                    - stack_height as f32 * half_extents.x;
+                let y = fi * shift.y + offset.y;
+                let z = (fi * shift.z / 2.0) + (fj - fi) * shift.z + offset.z
+                    - stack_height as f32 * half_extents.z;
+
+                // Build the rigid body.
+                let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
+                let handle = bodies.insert(rigid_body);
+                let collider =
+                    ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z).build();
+                colliders.insert(collider, handle, bodies);
+            }
+        }
+    }
+}
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 200.0;
+    let ground_height = 0.1;
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .translation(0.0, -ground_height, 0.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let cube_size = 1.0;
+    let hext = Vector3::repeat(cube_size);
+    let bottomy = cube_size * 50.0;
+    create_pyramid(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(-110.0, bottomy, 0.0),
+        12,
+        hext,
+    );
+    create_pyramid(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(-80.0, bottomy, 0.0),
+        12,
+        hext,
+    );
+    create_pyramid(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(-50.0, bottomy, 0.0),
+        12,
+        hext,
+    );
+    create_pyramid(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(-20.0, bottomy, 0.0),
+        12,
+        hext,
+    );
+    create_wall(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(-2.0, bottomy, 0.0),
+        12,
+        hext,
+    );
+    create_wall(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(4.0, bottomy, 0.0),
+        12,
+        hext,
+    );
+    create_wall(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(10.0, bottomy, 0.0),
+        12,
+        hext,
+    );
+    create_tower_circle(
+        &mut bodies,
+        &mut colliders,
+        Vector3::new(25.0, bottomy, 0.0),
+        8,
+        24,
+        hext,
+    );
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
+    testbed.run()
+}

benchmarks3d/trimesh3.rs

@@ -0,0 +1,88 @@
+use na::Point3;
+use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed3d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 200.0f32;
+    let ground_height = 1.0;
+    let nsubdivs = 20;
+
+    let quad = rapier3d::ncollide::procedural::quad(ground_size, ground_size, nsubdivs, nsubdivs);
+    let indices = quad
+        .flat_indices()
+        .chunks(3)
+        .map(|is| Point3::new(is[0], is[2], is[1]))
+        .collect();
+    let mut vertices = quad.coords;
+
+    // ncollide generates a quad with `z` as the normal.
+    // so we switch z and y here and set a random altitude at each point.
+    for p in vertices.iter_mut() {
+        p.z = p.y;
+        p.y = (p.x.sin() + p.z.cos()) * ground_height;
+
+        if p.x.abs() == ground_size / 2.0 || p.z.abs() == ground_size / 2.0 {
+            p.y = 10.0;
+        }
+    }
+
+    let rigid_body = RigidBodyBuilder::new_static().build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::trimesh(vertices, indices).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 8;
+    let rad = 1.0;
+
+    let shift = rad * 2.0 + rad;
+    let centerx = shift * (num / 2) as f32;
+    let centery = shift / 2.0;
+    let centerz = shift * (num / 2) as f32;
+
+    for j in 0usize..47 {
+        for i in 0..num {
+            for k in 0usize..num {
+                let x = i as f32 * shift - centerx;
+                let y = j as f32 * shift + centery + 3.0;
+                let z = k as f32 * shift - centerz;
+
+                // Build the rigid body.
+                let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
+                let handle = bodies.insert(rigid_body);
+
+                if j % 2 == 0 {
+                    let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
+                    colliders.insert(collider, handle, &mut bodies);
+                } else {
+                    let collider = ColliderBuilder::ball(rad).build();
+                    colliders.insert(collider, handle, &mut bodies);
+                }
+            }
+        }
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
+    testbed.run()
+}

examples2d/add_remove2.rs

@@ -15,7 +15,7 @@ pub fn init_world(testbed: &mut Testbed) {
             .translation(0.0, 10.0)
             .build();
         let handle = physics.bodies.insert(rigid_body);
-        let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+        let collider = ColliderBuilder::cuboid(rad, rad).build();
         physics
             .colliders
             .insert(collider, handle, &mut physics.bodies);

examples2d/balls2.rs

@@ -50,7 +50,7 @@ pub fn init_world(testbed: &mut Testbed) {
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new(status).translation(x, y).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            let collider = ColliderBuilder::ball(rad).build();
             colliders.insert(collider, handle, &mut bodies);
         }
     }

examples2d/boxes2.rs

@@ -55,7 +55,7 @@ pub fn init_world(testbed: &mut Testbed) {
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+            let collider = ColliderBuilder::cuboid(rad, rad).build();
             colliders.insert(collider, handle, &mut bodies);
         }
     }

examples2d/capsules2.rs

@@ -56,9 +56,7 @@ pub fn init_world(testbed: &mut Testbed) {
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::capsule_y(rad * 1.5, rad)
-                .density(1.0)
-                .build();
+            let collider = ColliderBuilder::capsule_y(rad * 1.5, rad).build();
             colliders.insert(collider, handle, &mut bodies);
         }
     }

examples2d/debug_box_ball2.rs

@@ -28,7 +28,7 @@ pub fn init_world(testbed: &mut Testbed) {
         .can_sleep(false)
         .build();
     let handle = bodies.insert(rigid_body);
-    let collider = ColliderBuilder::ball(rad).density(1.0).build();
+    let collider = ColliderBuilder::ball(rad).build();
     colliders.insert(collider, handle, &mut bodies);
 
     /*

examples2d/heightfield2.rs

@@ -50,10 +50,10 @@ pub fn init_world(testbed: &mut Testbed) {
             let handle = bodies.insert(rigid_body);
 
             if j % 2 == 0 {
-                let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+                let collider = ColliderBuilder::cuboid(rad, rad).build();
                 colliders.insert(collider, handle, &mut bodies);
             } else {
-                let collider = ColliderBuilder::ball(rad).density(1.0).build();
+                let collider = ColliderBuilder::ball(rad).build();
                 colliders.insert(collider, handle, &mut bodies);
             }
         }

examples2d/joints2.rs

@@ -40,7 +40,7 @@ pub fn init_world(testbed: &mut Testbed) {
                 .translation(fk * shift, -fi * shift)
                 .build();
             let child_handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            let collider = ColliderBuilder::ball(rad).build();
             colliders.insert(collider, child_handle, &mut bodies);
 
             // Vertical joint.

examples2d/kinematic2.rs

@@ -42,7 +42,7 @@ pub fn init_world(testbed: &mut Testbed) {
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+            let collider = ColliderBuilder::cuboid(rad, rad).build();
             colliders.insert(collider, handle, &mut bodies);
         }
     }
@@ -54,9 +54,7 @@ pub fn init_world(testbed: &mut Testbed) {
         .translation(-10.0 * rad, 1.5 + 0.8)
         .build();
     let platform_handle = bodies.insert(platform_body);
-    let collider = ColliderBuilder::cuboid(rad * 10.0, rad)
-        .density(1.0)
-        .build();
+    let collider = ColliderBuilder::cuboid(rad * 10.0, rad).build();
     colliders.insert(collider, platform_handle, &mut bodies);
 
     /*

examples2d/pyramid2.rs

@@ -42,7 +42,7 @@ pub fn init_world(testbed: &mut Testbed) {
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+            let collider = ColliderBuilder::cuboid(rad, rad).build();
             colliders.insert(collider, handle, &mut bodies);
         }
     }

examples2d/sensor2.rs

@@ -40,7 +40,7 @@ pub fn init_world(testbed: &mut Testbed) {
         // Build the rigid body.
         let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y).build();
         let handle = bodies.insert(rigid_body);
-        let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+        let collider = ColliderBuilder::cuboid(rad, rad).build();
         colliders.insert(collider, handle, &mut bodies);
 
         testbed.set_body_color(handle, Point3::new(0.5, 0.5, 1.0));
@@ -58,7 +58,7 @@ pub fn init_world(testbed: &mut Testbed) {
 
     // Solid cube attached to the sensor which
     // other colliders can touch.
-    let collider = ColliderBuilder::cuboid(rad, rad).density(1.0).build();
+    let collider = ColliderBuilder::cuboid(rad, rad).build();
     colliders.insert(collider, sensor_handle, &mut bodies);
 
     // We create a collider desc without density because we don't

examples2d/stress_joint_ball2.rs

@@ -37,7 +37,7 @@ pub fn init_world(testbed: &mut Testbed) {
                 .translation(fk * shift, -fi * shift)
                 .build();
             let child_handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            let collider = ColliderBuilder::ball(rad).build();
             colliders.insert(collider, child_handle, &mut bodies);
 
             // Vertical joint.

examples2d/stress_joint_fixed2.rs

@@ -42,7 +42,7 @@ pub fn init_world(testbed: &mut Testbed) {
                         .translation(x + fk * shift, y - fi * shift)
                         .build();
                     let child_handle = bodies.insert(rigid_body);
-                    let collider = ColliderBuilder::ball(rad).density(1.0).build();
+                    let collider = ColliderBuilder::ball(rad).build();
                     colliders.insert(collider, child_handle, &mut bodies);
 
                     // Vertical joint.

examples3d/add_remove3.rs

@@ -15,7 +15,7 @@ pub fn init_world(testbed: &mut Testbed) {
             .translation(0.0, 10.0, 0.0)
             .build();
         let handle = physics.bodies.insert(rigid_body);
-        let collider = ColliderBuilder::cuboid(rad, rad, rad).density(1.0).build();
+        let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
         physics
             .colliders
             .insert(collider, handle, &mut physics.bodies);

examples3d/all_examples3.rs

@@ -11,24 +11,17 @@ use rapier_testbed3d::Testbed;
 use std::cmp::Ordering;
 
 mod add_remove3;
-mod balls3;
-mod boxes3;
-mod capsules3;
 mod compound3;
 mod debug_boxes3;
 mod debug_triangle3;
 mod domino3;
 mod heightfield3;
 mod joints3;
-mod kinematic3;
-mod pyramid3;
+mod keva3;
+mod platform3;
+mod primitives3;
 mod sensor3;
 mod stacks3;
-mod stress_joint_ball3;
-mod stress_joint_fixed3;
-mod stress_joint_prismatic3;
-mod stress_joint_revolute3;
-mod stress_keva3;
 mod trimesh3;
 
 fn demo_name_from_command_line() -> Option<String> {
@@ -69,31 +62,18 @@ pub fn main() {
 
     let mut builders: Vec<(_, fn(&mut Testbed))> = vec![
         ("Add remove", add_remove3::init_world),
-        ("Balls", balls3::init_world),
-        ("Boxes", boxes3::init_world),
-        ("Capsules", capsules3::init_world),
+        ("Primitives", primitives3::init_world),
         ("Compound", compound3::init_world),
         ("Domino", domino3::init_world),
         ("Heightfield", heightfield3::init_world),
         ("Joints", joints3::init_world),
-        ("Kinematic", kinematic3::init_world),
+        ("Platform", platform3::init_world),
         ("Stacks", stacks3::init_world),
-        ("Pyramid", pyramid3::init_world),
         ("Sensor", sensor3::init_world),
         ("Trimesh", trimesh3::init_world),
+        ("Keva tower", keva3::init_world),
         ("(Debug) boxes", debug_boxes3::init_world),
         ("(Debug) triangle", debug_triangle3::init_world),
-        ("(Stress test) joint ball", stress_joint_ball3::init_world),
-        ("(Stress test) joint fixed", stress_joint_fixed3::init_world),
-        (
-            "(Stress test) joint revolute",
-            stress_joint_revolute3::init_world,
-        ),
-        (
-            "(Stress test) joint prismatic",
-            stress_joint_prismatic3::init_world,
-        ),
-        ("(Stress test) keva tower", stress_keva3::init_world),
     ];
 
     // Lexicographic sort, with stress tests moved at the end of the list.

examples3d/balls3.rs

@@ -1,29 +0,0 @@
-use na::Point3;
-use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
-use rapier3d::geometry::{ColliderBuilder, ColliderSet};
-use rapier_testbed3d::Testbed;
-
-pub fn init_world(testbed: &mut Testbed) {
-    /*
-     * World
-     */
-    let mut bodies = RigidBodySet::new();
-    let mut colliders = ColliderSet::new();
-    let joints = JointSet::new();
-
-    let rb = RigidBodyBuilder::new_dynamic().build();
-    let co = ColliderBuilder::cuboid(0.5, 0.5, 0.5).build();
-    let h = bodies.insert(rb);
-    colliders.insert(co, h, &mut bodies);
-
-    /*
-     * Set up the testbed.
-     */
-    testbed.set_world(bodies, colliders, joints);
-    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
-}
-
-fn main() {
-    let testbed = Testbed::from_builders(0, vec![("Balls", init_world)]);
-    testbed.run()
-}

examples3d/compound3.rs

@@ -14,7 +14,7 @@ pub fn init_world(testbed: &mut Testbed) {
     /*
      * Ground
      */
-    let ground_size = 200.1;
+    let ground_size = 50.0;
     let ground_height = 0.1;
 
     let rigid_body = RigidBodyBuilder::new_static()
@@ -37,7 +37,7 @@ pub fn init_world(testbed: &mut Testbed) {
 
     let mut offset = -(num as f32) * (rad * 2.0 + rad) * 0.5;
 
-    for j in 0usize..25 {
+    for j in 0usize..15 {
         for i in 0..num {
             for k in 0usize..num {
                 let x = i as f32 * shift * 5.0 - centerx + offset;

examples3d/debug_boxes3.rs

@@ -31,7 +31,7 @@ pub fn init_world(testbed: &mut Testbed) {
         .can_sleep(false)
         .build();
     let handle = bodies.insert(rigid_body);
-    let collider = ColliderBuilder::cuboid(2.0, 0.1, 1.0).density(1.0).build();
+    let collider = ColliderBuilder::cuboid(2.0, 0.1, 1.0).build();
     colliders.insert(collider, handle, &mut bodies);
 
     /*

examples3d/debug_triangle3.rs

@@ -32,7 +32,7 @@ pub fn init_world(testbed: &mut Testbed) {
         .can_sleep(false)
         .build();
     let handle = bodies.insert(rigid_body);
-    let collider = ColliderBuilder::cuboid(20.0, 0.1, 1.0).density(1.0).build();
+    let collider = ColliderBuilder::cuboid(20.0, 0.1, 1.0).build();
     colliders.insert(collider, handle, &mut bodies);
 
     /*

examples3d/domino3.rs

@@ -58,9 +58,7 @@ pub fn init_world(testbed: &mut Testbed) {
                     * rot;
             let rigid_body = RigidBodyBuilder::new_dynamic().position(position).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(thickness, width * 2.0, width)
-                .density(1.0)
-                .build();
+            let collider = ColliderBuilder::cuboid(thickness, width * 2.0, width).build();
             colliders.insert(collider, handle, &mut bodies);
             testbed.set_body_color(handle, colors[i % 2]);
         } else {

examples3d/heightfield3.rs

@@ -14,7 +14,7 @@ pub fn init_world(testbed: &mut Testbed) {
     /*
      * Ground
      */
-    let ground_size = Vector3::new(200.0, 1.0, 200.0);
+    let ground_size = Vector3::new(100.0, 1.0, 100.0);
     let nsubdivs = 20;
 
     let heights = DMatrix::from_fn(nsubdivs + 1, nsubdivs + 1, |i, j| {
@@ -43,7 +43,7 @@ pub fn init_world(testbed: &mut Testbed) {
     let centery = shift / 2.0;
     let centerz = shift * (num / 2) as f32;
 
-    for j in 0usize..47 {
+    for j in 0usize..20 {
         for i in 0..num {
             for k in 0usize..num {
                 let x = i as f32 * shift - centerx;
@@ -55,10 +55,10 @@ pub fn init_world(testbed: &mut Testbed) {
                 let handle = bodies.insert(rigid_body);
 
                 if j % 2 == 0 {
-                    let collider = ColliderBuilder::cuboid(rad, rad, rad).density(1.0).build();
+                    let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
                     colliders.insert(collider, handle, &mut bodies);
                 } else {
-                    let collider = ColliderBuilder::ball(rad).density(1.0).build();
+                    let collider = ColliderBuilder::ball(rad).build();
                     colliders.insert(collider, handle, &mut bodies);
                 }
             }

examples3d/joints3.rs

@@ -150,7 +150,7 @@ fn create_fixed_joints(
                 .translation(origin.x + fk * shift, origin.y, origin.z + fi * shift)
                 .build();
             let child_handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            let collider = ColliderBuilder::ball(rad).build();
             colliders.insert(collider, child_handle, bodies);
 
             // Vertical joint.
@@ -205,7 +205,7 @@ fn create_ball_joints(
                 .translation(fk * shift, 0.0, fi * shift)
                 .build();
             let child_handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::ball(rad).density(1.0).build();
+            let collider = ColliderBuilder::ball(rad).build();
             colliders.insert(collider, child_handle, bodies);
 
             // Vertical joint.

examples3d/keva3.rs

@@ -0,0 +1,144 @@
+use na::{Point3, Vector3};
+use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed3d::Testbed;
+
+pub fn build_block(
+    testbed: &mut Testbed,
+    bodies: &mut RigidBodySet,
+    colliders: &mut ColliderSet,
+    half_extents: Vector3<f32>,
+    shift: Vector3<f32>,
+    mut numx: usize,
+    numy: usize,
+    mut numz: usize,
+) {
+    let dimensions = [half_extents.xyz(), half_extents.zyx()];
+    let block_width = 2.0 * half_extents.z * numx as f32;
+    let block_height = 2.0 * half_extents.y * numy as f32;
+    let spacing = (half_extents.z * numx as f32 - half_extents.x) / (numz as f32 - 1.0);
+    let mut color0 = Point3::new(0.7, 0.5, 0.9);
+    let mut color1 = Point3::new(0.6, 1.0, 0.6);
+
+    for i in 0..numy {
+        std::mem::swap(&mut numx, &mut numz);
+        let dim = dimensions[i % 2];
+        let y = dim.y * i as f32 * 2.0;
+
+        for j in 0..numx {
+            let x = if i % 2 == 0 {
+                spacing * j as f32 * 2.0
+            } else {
+                dim.x * j as f32 * 2.0
+            };
+
+            for k in 0..numz {
+                let z = if i % 2 == 0 {
+                    dim.z * k as f32 * 2.0
+                } else {
+                    spacing * k as f32 * 2.0
+                };
+
+                // Build the rigid body.
+                let rigid_body = RigidBodyBuilder::new_dynamic()
+                    .translation(
+                        x + dim.x + shift.x,
+                        y + dim.y + shift.y,
+                        z + dim.z + shift.z,
+                    )
+                    .build();
+                let handle = bodies.insert(rigid_body);
+                let collider = ColliderBuilder::cuboid(dim.x, dim.y, dim.z).build();
+                colliders.insert(collider, handle, bodies);
+
+                testbed.set_body_color(handle, color0);
+                std::mem::swap(&mut color0, &mut color1);
+            }
+        }
+    }
+
+    // Close the top.
+    let dim = half_extents.zxy();
+
+    for i in 0..(block_width / (dim.x as f32 * 2.0)) as usize {
+        for j in 0..(block_width / (dim.z as f32 * 2.0)) as usize {
+            // Build the rigid body.
+            let rigid_body = RigidBodyBuilder::new_dynamic()
+                .translation(
+                    i as f32 * dim.x * 2.0 + dim.x + shift.x,
+                    dim.y + shift.y + block_height,
+                    j as f32 * dim.z * 2.0 + dim.z + shift.z,
+                )
+                .build();
+            let handle = bodies.insert(rigid_body);
+            let collider = ColliderBuilder::cuboid(dim.x, dim.y, dim.z).build();
+            colliders.insert(collider, handle, bodies);
+            testbed.set_body_color(handle, color0);
+            std::mem::swap(&mut color0, &mut color1);
+        }
+    }
+}
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 50.0;
+    let ground_height = 0.1;
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .translation(0.0, -ground_height, 0.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let half_extents = Vector3::new(0.02, 0.1, 0.4) / 2.0 * 10.0;
+    let mut block_height = 0.0;
+    // These should only be set to odd values otherwise
+    // the blocks won't align in the nicest way.
+    let numy = [0, 9, 13, 17, 21, 41];
+    let mut num_blocks_built = 0;
+
+    for i in (1..=5).rev() {
+        let numx = i;
+        let numy = numy[i];
+        let numz = numx * 3 + 1;
+        let block_width = numx as f32 * half_extents.z * 2.0;
+        build_block(
+            testbed,
+            &mut bodies,
+            &mut colliders,
+            half_extents,
+            Vector3::new(-block_width / 2.0, block_height, -block_width / 2.0),
+            numx,
+            numy,
+            numz,
+        );
+        block_height += numy as f32 * half_extents.y * 2.0 + half_extents.x * 2.0;
+        num_blocks_built += numx * numy * numz;
+    }
+
+    println!("Num keva blocks: {}", num_blocks_built);
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
+    testbed.run()
+}

examples3d/platform3.rs

@@ -45,7 +45,7 @@ pub fn init_world(testbed: &mut Testbed) {
                 // Build the rigid body.
                 let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
                 let handle = bodies.insert(rigid_body);
-                let collider = ColliderBuilder::cuboid(rad, rad, rad).density(1.0).build();
+                let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
                 colliders.insert(collider, handle, &mut bodies);
             }
         }
@@ -58,9 +58,7 @@ pub fn init_world(testbed: &mut Testbed) {
         .translation(0.0, 1.5 + 0.8, -10.0 * rad)
         .build();
     let platform_handle = bodies.insert(platform_body);
-    let collider = ColliderBuilder::cuboid(rad * 10.0, rad, rad * 10.0)
-        .density(1.0)
-        .build();
+    let collider = ColliderBuilder::cuboid(rad * 10.0, rad, rad * 10.0).build();
     colliders.insert(collider, platform_handle, &mut bodies);
 
     /*

examples3d/primitives3.rs

@@ -0,0 +1,75 @@
+use na::Point3;
+use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet};
+use rapier_testbed3d::Testbed;
+
+pub fn init_world(testbed: &mut Testbed) {
+    /*
+     * World
+     */
+    let mut bodies = RigidBodySet::new();
+    let mut colliders = ColliderSet::new();
+    let joints = JointSet::new();
+
+    /*
+     * Ground
+     */
+    let ground_size = 100.1;
+    let ground_height = 0.1;
+
+    let rigid_body = RigidBodyBuilder::new_static()
+        .translation(0.0, -ground_height, 0.0)
+        .build();
+    let handle = bodies.insert(rigid_body);
+    let collider = ColliderBuilder::cuboid(ground_size, ground_height, ground_size).build();
+    colliders.insert(collider, handle, &mut bodies);
+
+    /*
+     * Create the cubes
+     */
+    let num = 8;
+    let rad = 1.0;
+
+    let shift = rad * 2.0 + rad;
+    let centerx = shift * (num / 2) as f32;
+    let centery = shift / 2.0;
+    let centerz = shift * (num / 2) as f32;
+
+    let mut offset = -(num as f32) * (rad * 2.0 + rad) * 0.5;
+
+    for j in 0usize..20 {
+        for i in 0..num {
+            for k in 0usize..num {
+                let x = i as f32 * shift - centerx + offset;
+                let y = j as f32 * shift + centery + 3.0;
+                let z = k as f32 * shift - centerz + offset;
+
+                // Build the rigid body.
+                let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
+                let handle = bodies.insert(rigid_body);
+
+                let collider = match j % 2 {
+                    0 => ColliderBuilder::cuboid(rad, rad, rad).build(),
+                    1 => ColliderBuilder::ball(rad).build(),
+                    // 2 => ColliderBuilder::capsule_y(rad, rad).build(),
+                    _ => unreachable!(),
+                };
+
+                colliders.insert(collider, handle, &mut bodies);
+            }
+        }
+
+        offset -= 0.05 * rad * (num as f32 - 1.0);
+    }
+
+    /*
+     * Set up the testbed.
+     */
+    testbed.set_world(bodies, colliders, joints);
+    testbed.look_at(Point3::new(100.0, 100.0, 100.0), Point3::origin());
+}
+
+fn main() {
+    let testbed = Testbed::from_builders(0, vec![("Boxes", init_world)]);
+    testbed.run()
+}

examples3d/sensor3.rs

@@ -43,7 +43,7 @@ pub fn init_world(testbed: &mut Testbed) {
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(rad, rad, rad).density(1.0).build();
+            let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
             colliders.insert(collider, handle, &mut bodies);
 
             testbed.set_body_color(handle, Point3::new(0.5, 0.5, 1.0));
@@ -56,13 +56,13 @@ pub fn init_world(testbed: &mut Testbed) {
 
     // Rigid body so that the sensor can move.
     let sensor = RigidBodyBuilder::new_dynamic()
-        .translation(0.0, 10.0, 0.0)
+        .translation(0.0, 5.0, 0.0)
         .build();
     let sensor_handle = bodies.insert(sensor);
 
     // Solid cube attached to the sensor which
     // other colliders can touch.
-    let collider = ColliderBuilder::cuboid(rad, rad, rad).density(1.0).build();
+    let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
     colliders.insert(collider, sensor_handle, &mut bodies);
 
     // We create a collider desc without density because we don't

examples3d/stacks3.rs

@@ -27,9 +27,8 @@ fn create_tower_circle(
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new_dynamic().position(pos).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z)
-                .density(1.0)
-                .build();
+            let collider =
+                ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z).build();
             colliders.insert(collider, handle, bodies);
         }
     }
@@ -55,9 +54,8 @@ fn create_wall(
             // Build the rigid body.
             let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
             let handle = bodies.insert(rigid_body);
-            let collider = ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z)
-                .density(1.0)
-                .build();
+            let collider =
+                ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z).build();
             colliders.insert(collider, handle, bodies);
         }
     }
@@ -88,9 +86,7 @@ fn create_pyramid(
                 let rigid_body = RigidBodyBuilder::new_dynamic().translation(x, y, z).build();
                 let handle = bodies.insert(rigid_body);
                 let collider =
-                    ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z)
-                        .density(1.0)
-                        .build();
+                    ColliderBuilder::cuboid(half_extents.x, half_extents.y, half_extents.z).build();
                 colliders.insert(collider, handle, bodies);
             }
         }
@@ -124,27 +120,7 @@ pub fn init_world(testbed: &mut Testbed) {
     let cube_size = 1.0;
     let hext = Vector3::repeat(cube_size);
     let bottomy = cube_size * 50.0;
-    create_pyramid(
-        &mut bodies,
-        &mut colliders,
-        Vector3::new(-110.0, bottomy, 0.0),
-        12,
-        hext,
-    );
-    create_pyramid(
-        &mut bodies,
-        &mut colliders,
-        Vector3::new(-80.0, bottomy, 0.0),
-        12,
-        hext,
-    );
-    create_pyramid(
-        &mut bodies,
-        &mut colliders,
-        Vector3::new(-50.0, bottomy, 0.0),
-        12,
-        hext,
-    );
+
     create_pyramid(
         &mut bodies,
         &mut colliders,

examples3d/trimesh3.rs

@@ -14,7 +14,7 @@ pub fn init_world(testbed: &mut Testbed) {
     /*
      * Ground
      */
-    let ground_size = 200.0f32;
+    let ground_size = 100.0f32;
     let ground_height = 1.0;
     let nsubdivs = 20;
 
@@ -53,7 +53,7 @@ pub fn init_world(testbed: &mut Testbed) {
     let centery = shift / 2.0;
     let centerz = shift * (num / 2) as f32;
 
-    for j in 0usize..47 {
+    for j in 0usize..20 {
         for i in 0..num {
             for k in 0usize..num {
                 let x = i as f32 * shift - centerx;
@@ -65,10 +65,10 @@ pub fn init_world(testbed: &mut Testbed) {
                 let handle = bodies.insert(rigid_body);
 
                 if j % 2 == 0 {
-                    let collider = ColliderBuilder::cuboid(rad, rad, rad).density(1.0).build();
+                    let collider = ColliderBuilder::cuboid(rad, rad, rad).build();
                     colliders.insert(collider, handle, &mut bodies);
                 } else {
-                    let collider = ColliderBuilder::ball(rad).density(1.0).build();
+                    let collider = ColliderBuilder::ball(rad).build();
                     colliders.insert(collider, handle, &mut bodies);
                 }
             }

src/geometry/collider.rs

@@ -212,7 +212,7 @@ pub struct ColliderBuilder {
     /// The shape of the collider to be built.
     pub shape: Shape,
     /// The density of the collider to be built.
-    pub density: f32,
+    density: Option<f32>,
     /// The friction coefficient of the collider to be built.
     pub friction: f32,
     /// The restitution coefficient of the collider to be built.
@@ -228,7 +228,7 @@ impl ColliderBuilder {
     pub fn new(shape: Shape) -> Self {
         Self {
             shape,
-            density: 1.0,
+            density: None,
             friction: Self::default_friction(),
             restitution: 0.0,
             delta: Isometry::identity(),
@@ -236,6 +236,12 @@ impl ColliderBuilder {
         }
     }
 
+    /// The density of the collider being built.
+    pub fn get_density(&self) -> f32 {
+        let default_density = if self.is_sensor { 0.0 } else { 1.0 };
+        self.density.unwrap_or(default_density)
+    }
+
     /// Initialize a new collider builder with a ball shape defined by its radius.
     pub fn ball(radius: f32) -> Self {
         Self::new(Shape::Ball(Ball::new(radius)))
@@ -349,7 +355,7 @@ impl ColliderBuilder {
 
     /// Sets the density of the collider this builder will build.
     pub fn density(mut self, density: f32) -> Self {
-        self.density = density;
+        self.density = Some(density);
         self
     }
 
@@ -395,9 +401,11 @@ impl ColliderBuilder {
 
     /// Buildes a new collider attached to the given rigid-body.
     pub fn build(&self) -> Collider {
+        let density = self.get_density();
+
         Collider {
             shape: self.shape.clone(),
-            density: self.density,
+            density,
             friction: self.friction,
             restitution: self.restitution,
             delta: self.delta,