From 8d95fbe8f393810cef7c052ffd970aee6bd3369e Mon Sep 17 00:00:00 2001
From: Hendrik Mans <hendrik@mans.de>
Date: Mon, 26 Sep 2022 16:24:06 +0200
Subject: [PATCH] Density

---
 .changeset/dry-planes-applaud.md                      |  5 +++++
 apps/spacerage/src/scenes/gameplay/Asteroids.tsx      |  1 +
 .../src/colliders/ConvexHullCollider.tsx              | 11 +++++++++--
 3 files changed, 15 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/dry-planes-applaud.md

diff --git a/.changeset/dry-planes-applaud.md b/.changeset/dry-planes-applaud.md
new file mode 100644
index 000000000..d23029c3f
--- /dev/null
+++ b/.changeset/dry-planes-applaud.md
@@ -0,0 +1,5 @@
+---
+"@hmans/physics3d": patch
+---
+
+Added `density` prop on collider.
diff --git a/apps/spacerage/src/scenes/gameplay/Asteroids.tsx b/apps/spacerage/src/scenes/gameplay/Asteroids.tsx
index fff9c2dea..9da27813a 100644
--- a/apps/spacerage/src/scenes/gameplay/Asteroids.tsx
+++ b/apps/spacerage/src/scenes/gameplay/Asteroids.tsx
@@ -48,6 +48,7 @@ export const Asteroids = () => {
             >
               <group>
                 <ConvexHullCollider
+                  density={5}
                   collisionGroups={interactionGroups(Layers.Asteroid, [
                     Layers.Asteroid,
                     Layers.Player
diff --git a/packages/hmans-physics3d/src/colliders/ConvexHullCollider.tsx b/packages/hmans-physics3d/src/colliders/ConvexHullCollider.tsx
index 58164b19b..864eb673b 100644
--- a/packages/hmans-physics3d/src/colliders/ConvexHullCollider.tsx
+++ b/packages/hmans-physics3d/src/colliders/ConvexHullCollider.tsx
@@ -13,12 +13,13 @@ import { usePhysicsWorld } from "../World"
 import { multiplyByMatrix } from "../util/multiplyByMatrix"
 
 export type ConvexHullColliderProps = {
+  density?: number
   points: Float32Array
   collisionGroups?: RAPIER.InteractionGroups
 } & GroupProps
 
 function ConvexHullCollider(
-  { points, collisionGroups, ...props }: ConvexHullColliderProps,
+  { points, collisionGroups, density = 1, ...props }: ConvexHullColliderProps,
   ref: ForwardedRef<THREE.Group>
 ) {
   const { world } = usePhysicsWorld()
@@ -53,7 +54,13 @@ function ConvexHullCollider(
     /* Create the collider */
     const collider = world.createCollider(desc, rb.body)
 
-    if (collisionGroups) collider.setCollisionGroups(collisionGroups)
+    if (density !== undefined) {
+      collider.setDensity(density)
+    }
+
+    if (collisionGroups !== undefined) {
+      collider.setCollisionGroups(collisionGroups)
+    }
 
     /* Destroy the collider on unmount */
     return () => world.removeCollider(collider, true)