feat: add support for Voxels collider (#823)

* feat: start adding voxels support and some additional testbed demo settings

* feat: add support for parry’s new Voxels collider shape

* fix voxels demos

* feat: support rectangular voxels and additional voxels initialization

* chore: switch to parry 0.20

* chore: fix cargo doc

* Fix testbed build

src_testbed/testbed.rs

@@ -1014,18 +1014,20 @@ fn draw_contacts(_nf: &NarrowPhase, _colliders: &ColliderSet) {
 #[cfg(feature = "dim3")]
 fn setup_graphics_environment(mut commands: Commands) {
     commands.insert_resource(AmbientLight {
-        brightness: 100.0,
+        brightness: 200.0,
         ..Default::default()
     });
 
     commands.spawn((
         DirectionalLight {
-            shadows_enabled: false,
+            // shadows_enabled: true,
             ..Default::default()
         },
         Transform {
-            translation: Vec3::new(10.0, 2.0, 10.0),
-            rotation: Quat::from_rotation_x(-std::f32::consts::FRAC_PI_4),
+            translation: Vec3::new(-100.0, 200.0, -100.0),
+            rotation: Quat::from_rotation_x(
+                -(std::f32::consts::FRAC_PI_4 + std::f32::consts::FRAC_PI_6),
+            ),
             ..Default::default()
         },
     ));