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use na::{Point3, Translation3, UnitQuaternion, 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 = 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 = 4000;
let width = 1.0;
let thickness = 0.1;
let colors = [Point3::new(0.7, 0.5, 0.9), Point3::new(0.6, 1.0, 0.6)];
let mut curr_angle = 0.0;
let mut curr_rad = 10.0;
let mut prev_angle;
let mut skip = 0;
for i in 0..num {
let perimeter = 2.0 * std::f32::consts::PI * curr_rad;
let spacing = thickness * 4.0;
prev_angle = curr_angle;
curr_angle += 2.0 * std::f32::consts::PI * spacing / perimeter;
let (x, z) = curr_angle.sin_cos();
// Build the rigid body.
let two_pi = 2.0 * std::f32::consts::PI;
let nudged = curr_angle % two_pi < prev_angle % two_pi;
let tilt = if nudged || i == num - 1 { 0.2 } else { 0.0 };
if skip == 0 {
let rot = UnitQuaternion::new(Vector3::y() * curr_angle);
let tilt = UnitQuaternion::new(rot * Vector3::z() * tilt);
let position =
Translation3::new(x * curr_rad, width * 2.0 + ground_height, z * curr_rad)
* tilt
* 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();
colliders.insert(collider, handle, &mut bodies);
testbed.set_body_color(handle, colors[i % 2]);
} else {
skip -= 1;
}
if nudged {
skip = 5;
}
curr_rad += 1.5 / perimeter;
}
/*
* 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()
}
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