Add 3D convex decomposition example.

examples3d/convex_decomposition3.rs

@@ -0,0 +1,134 @@
+use kiss3d::loader::obj;
+use na::{Isometry3, Point3, Translation3};
+use rapier3d::cdl::bounding_volume::{self, BoundingVolume};
+use rapier3d::cdl::transformation::vhacd::{VHACDParameters, VHACD};
+use rapier3d::dynamics::{JointSet, RigidBodyBuilder, RigidBodySet};
+use rapier3d::geometry::{ColliderBuilder, ColliderSet, ColliderShape};
+use rapier_testbed3d::Testbed;
+use std::path::Path;
+
+/*
+ * 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 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 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 = na::one();
+        let mtl_path = Path::new("");
+
+        let mut compound_parts = Vec::new();
+        println!("Parsing and decomposing: {}", obj_path);
+        let obj = obj::parse_file(&Path::new(&obj_path), &mtl_path, "");
+
+        if let Ok(model) = obj {
+            let meshes: Vec<_> = model
+                .into_iter()
+                .map(|mesh| mesh.1.to_trimesh().unwrap())
+                .collect();
+
+            // Compute the size of the model, to scale it and have similar size for everything.
+            let mut aabb =
+                bounding_volume::details::point_cloud_aabb(&deltas, &meshes[0].coords[..]);
+
+            for mesh in meshes[1..].iter() {
+                aabb.merge(&bounding_volume::details::point_cloud_aabb(
+                    &deltas,
+                    &mesh.coords[..],
+                ));
+            }
+
+            let center = aabb.center().coords;
+            let diag = (aabb.maxs - aabb.mins).norm();
+
+            for mut trimesh in meshes.into_iter() {
+                trimesh.translate_by(&Translation3::from(-center));
+                trimesh.scale_by_scalar(6.0 / diag);
+
+                let params = VHACDParameters::default();
+                let vertices = &trimesh.coords;
+                let indices = &trimesh.indices.unwrap_unified();
+                let vhacd = VHACD::decompose(&params, vertices, indices, true);
+
+                for (vertices, indices) in vhacd.compute_exact_convex_hulls(vertices, indices) {
+                    if let Some(convex) = ColliderShape::convex_mesh(vertices, &indices) {
+                        compound_parts.push(convex);
+                    }
+                }
+            }
+
+            // let compound = ColliderShape::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::new_dynamic().translation(x, y, z).build();
+                let handle = bodies.insert(body);
+
+                for part in &compound_parts {
+                    let collider = ColliderBuilder::new(part.clone()).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 models() -> Vec<String> {
+    vec![
+        "media/models/camel_decimated.obj".to_string(),
+        "media/models/chair.obj".to_string(),
+        "media/models/cup_decimated.obj".to_string(),
+        "media/models/dilo_decimated.obj".to_string(),
+        "media/models/feline_decimated.obj".to_string(),
+        "media/models/genus3_decimated.obj".to_string(),
+        "media/models/hand2_decimated.obj".to_string(),
+        "media/models/hand_decimated.obj".to_string(),
+        "media/models/hornbug.obj".to_string(),
+        "media/models/octopus_decimated.obj".to_string(),
+        "media/models/rabbit_decimated.obj".to_string(),
+        "media/models/rust_logo.obj".to_string(),
+        "media/models/rust_logo_simplified.obj".to_string(),
+        "media/models/screwdriver_decimated.obj".to_string(),
+        "media/models/table.obj".to_string(),
+        "media/models/tstTorusModel.obj".to_string(),
+        // "media/models/tstTorusModel2.obj".to_string(),
+        // "media/models/tstTorusModel3.obj".to_string(),
+    ]
+}