//IMPORTANT Time.fixedTime must match the timestep being used here. public static List <UnityEngine.Vector3> SimulateBall(BRigidBody ballRb, UnityEngine.Vector3 ballThrowForce, int numberOfSimulationSteps, bool reverseOrder) { var ballPositions = new List <UnityEngine.Vector3>(numberOfSimulationSteps); //Create a World Debug.Log("Initialize physics"); CollisionConfiguration CollisionConf; CollisionDispatcher Dispatcher; BroadphaseInterface Broadphase; CollisionWorld cw; ConstraintSolver Solver; BulletSharp.SoftBody.SoftBodyWorldInfo softBodyWorldInfo; //This should create a copy of the BPhysicsWorld with the same settings BPhysicsWorld bw = BPhysicsWorld.Get(); bw.CreatePhysicsWorld(out cw, out CollisionConf, out Dispatcher, out Broadphase, out Solver, out softBodyWorldInfo); World = (DiscreteDynamicsWorld)cw; //Copy all existing rigidbodies in scene // IMPORTANT rigidbodies must be added to the offline world in the same order that they are in the source world // this is because collisions must be resolved in the same order for the sim to be deterministic DiscreteDynamicsWorld sourceWorld = (DiscreteDynamicsWorld)bw.world; BulletSharp.RigidBody bulletBallRb = null; BulletSharp.Math.Matrix mm = BulletSharp.Math.Matrix.Identity; for (int i = 0; i < sourceWorld.NumCollisionObjects; i++) { CollisionObject co = sourceWorld.CollisionObjectArray[i]; if (co != null && co.UserObject is BRigidBody) { BRigidBody rb = (BRigidBody)co.UserObject; float mass = rb.isDynamic() ? rb.mass : 0f; BCollisionShape existingShape = rb.GetComponent <BCollisionShape>(); CollisionShape shape = null; if (existingShape is BSphereShape) { shape = ((BSphereShape)existingShape).CopyCollisionShape(); } else if (existingShape is BBoxShape) { shape = ((BBoxShape)existingShape).CopyCollisionShape(); } RigidBody bulletRB = null; BulletSharp.Math.Vector3 localInertia = new BulletSharp.Math.Vector3(); rb.CreateOrConfigureRigidBody(ref bulletRB, ref localInertia, shape, null); BulletSharp.Math.Vector3 pos = rb.GetCollisionObject().WorldTransform.Origin; BulletSharp.Math.Quaternion rot = rb.GetCollisionObject().WorldTransform.GetOrientation(); BulletSharp.Math.Matrix.AffineTransformation(1f, ref rot, ref pos, out mm); bulletRB.WorldTransform = mm; World.AddRigidBody(bulletRB, rb.groupsIBelongTo, rb.collisionMask); if (rb == ballRb) { bulletBallRb = bulletRB; bulletRB.ApplyCentralImpulse(ballThrowForce.ToBullet()); } } } //Step the simulation numberOfSimulationSteps times for (int i = 0; i < numberOfSimulationSteps; i++) { int numSteps = World.StepSimulation(1f / 60f, 10, 1f / 60f); ballPositions.Add(bulletBallRb.WorldTransform.Origin.ToUnity()); } UnityEngine.Debug.Log("ExitPhysics"); if (World != null) { //remove/dispose constraints int i; for (i = World.NumConstraints - 1; i >= 0; i--) { TypedConstraint constraint = World.GetConstraint(i); World.RemoveConstraint(constraint); constraint.Dispose(); } //remove the rigidbodies from the dynamics world and delete them for (i = World.NumCollisionObjects - 1; i >= 0; i--) { CollisionObject obj = World.CollisionObjectArray[i]; RigidBody body = obj as RigidBody; if (body != null && body.MotionState != null) { body.MotionState.Dispose(); } World.RemoveCollisionObject(obj); obj.Dispose(); } World.Dispose(); Broadphase.Dispose(); Dispatcher.Dispose(); CollisionConf.Dispose(); } if (Broadphase != null) { Broadphase.Dispose(); } if (Dispatcher != null) { Dispatcher.Dispose(); } if (CollisionConf != null) { CollisionConf.Dispose(); } return(ballPositions); }