resolves #6

src/lib/Physics.js

@@ -1,8 +1,17 @@
 import * as RAPIER from '@dimforge/rapier3d'
-import { Vector3 } from 'three';
+import { Quaternion, Vector3 } from 'three';
 class Physics{
     constructor(engine){
         this.engine = engine
+        this.started = false;
+    }
+
+    start(){
+        this.started = true;
+    }
+
+    stop(){
+        this.started = false;
     }
         
     init = async ()=>{
@@ -10,11 +19,11 @@ class Physics{
         let world = new RAPIER.World(gravity);
 
         // Create Ground.
-        let bodyDesc = RAPIER.RigidBodyDesc.fixed();
-        let body = world.createRigidBody(bodyDesc);
-        let colliderDesc = RAPIER.ColliderDesc.cuboid(100, 0, 100);
-        //bodyDesc.setTranslation(-50,0,-50);
-        world.createCollider(colliderDesc, body.handle);
+        // let bodyDesc = RAPIER.RigidBodyDesc.fixed();
+        // let body = world.createRigidBody(bodyDesc);
+        // let colliderDesc = RAPIER.ColliderDesc.cuboid(100, 0, 100);
+        // //bodyDesc.setTranslation(-50,0,-50);
+        // world.createCollider(colliderDesc, body.handle);
         this.world = world;
         this.physicsObjects = [];
         this.eventQueue = new RAPIER.EventQueue(true);
@@ -23,8 +32,18 @@ class Physics{
 
     add = (mesh, rigidBodyType, autoAnimate = true, postPhysicsFn, colliderType, colliderSettings = {}) => {
         const rigidBodyDesc = RAPIER.RigidBodyDesc[rigidBodyType]()
-        rigidBodyDesc.setTranslation(mesh.position.x, mesh.position.y, mesh.position.z)
-        mesh.quaternion && rigidBodyDesc.setRotation(mesh.quaternion)
+        let position, quaternion;
+        // if (colliderSettings.root){
+        //     // mesh.getWorldPosition(position = new Vector3());
+        //     // mesh.getWorldQuaternion(quaternion = new Quaternion());
+        //     position = colliderSettings.root.position;
+        //     quaternion = colliderSettings.root.quaternion;
+        // }else{
+            position = mesh.position;
+            quaternion = mesh.quaternion;
+        //}
+        rigidBodyDesc.setTranslation(position.x, position.y, position.z)
+        quaternion && rigidBodyDesc.setRotation(quaternion)
 
         // * Responsible for collision response
         const rigidBody = this.world.createRigidBody(rigidBodyDesc)
@@ -82,7 +101,10 @@ class Physics{
 
         // * Responsible for collision detection
         const collider = this.world.createCollider(colliderDesc, rigidBody)
-        mesh.quaternion && collider.setRotationWrtParent(mesh.quaternion)
+        if (colliderSettings.root){
+            collider.setTranslationWrtParent(colliderSettings.root.position)
+            collider.setRotationWrtParent(colliderSettings.root.quaternion)
+        }
         const physicsObject = { mesh, collider, rigidBody, fn: postPhysicsFn, autoAnimate }
         this.physicsObjects.push(physicsObject)
 
@@ -99,6 +121,9 @@ class Physics{
     }
 
     step(){
+        if (!this.started){
+            return;
+        }
         this.world.step(this.eventQueue)
 
         for (let po of this.physicsObjects) {