Hello all,
I’m somewhat new to Unity, and what I’m trying to do right now is instead of make a whole bunch of random little projects to try stuff out, I’m making a very feature-packed game with really simple mechanics.
The game is basically a sumo-wrestling type game, except each character controls a box. By pressing keys, they apply a force and rotation to their box, and they try to push the other box off of a platform.
So what I’m trying to do now is make the game work over the internet, but I’m running into trouble when the boxes start colliding.
What I did initially is have both the client and the server directly control their own box, and send the position and rotation to the other. The problem is that the boxes often clip into each other, and the collisions get screwed up. I also tried using an authoritative set up, but it was too laggy for the client to actually be competitive. What I think I need to do is figure out some way that I can do prediction with the client, and I’m struggling a little bit as to how I’m going to do that.
One of the ideas that I came up with is to have a system where both the client and the server directly control their own boxes, as well as sending RPCs with each player’s inputs to the other player. Then, every once in a while, e.g. every 0.1 seconds, the server and the client will compare their numbers for each player’s position, and interpolate between them, and continue simulating. So would this work? How would I do it?
If it helps at all, here’s the code that I have for the authoritative set up (a lot of it is from M2H’s tutorial)
#pragma strict
#pragma implicit
#pragma downcast
public var owner : NetworkPlayer;
//Last input value, we're saving this to save network messages/bandwidth.
private var lastClientHInput : float=0;
private var lastClientVInput : float=0;
private var lastClientJumpInput : float=0;
//The input values the server will execute on this object
private var serverCurrentHInput : float = 0;
private var serverCurrentVInput : float = 0;
private var serverCurrentJumpInput : float = 0;
private var clientCurrentHInput : float = 0;
private var clientCurrentVInput : float = 0;
var blueColor : Material;
var redColor : Material;
var moveForce = 5;
var moveTorque = 5;
var jumpForce = 20;
var jumpInterval = 0.5;
var useSlider = true;
private var goVector = Vector2(0,0);
private var jumpTime = 0.0;
private var jumps = 1;
/*private var keysPressed = 0;*/
private var forceMod = 0.0;
function Awake(){
// We are probably not the owner of this object: disable this script.
// RPC's and OnSerializeNetworkView will STILL get trough!
// The server ALWAYS run this script though
if(Network.isClient){
enabled=false; // disable this script (this enables Update());
}
}
@RPC
function SetPlayer(player : NetworkPlayer){
owner = player;
if(player==Network.player){
//Hey thats us! We can control this player: enable this script (this enables Update());
enabled=true;
}
}
function Update () {
if (useSlider == true) {
moveForce = SliderGUI.speedSlider;
moveTorque = SliderGUI.speedSlider;
}
/*if (Input.GetKeyDown(KeyCode.UpArrow) || Input.GetKeyDown(KeyCode.DownArrow) || Input.GetKeyDown(KeyCode.LeftArrow) || Input.GetKeyDown(KeyCode.RightArrow)) {
keysPressed ++;
}
if (Input.GetKeyUp(KeyCode.UpArrow) || Input.GetKeyUp(KeyCode.DownArrow) || Input.GetKeyUp(KeyCode.LeftArrow) || Input.GetKeyUp(KeyCode.RightArrow)) {
keysPressed --;
} */
/*
if ((Input.GetKey(KeyCode.UpArrow) Input.GetKey(KeyCode.LeftArrow)) || (Input.GetKey(KeyCode.UpArrow) Input.GetKey(KeyCode.RightArrow)) || (Input.GetKey(KeyCode.DownArrow) Input.GetKey(KeyCode.LeftArrow)) || (Input.GetKey(KeyCode.DownArrow) Input.GetKey(KeyCode.RightArrow))) {forceMod = Mathf.Sqrt(2)/2;} else {forceMod = 1;}
if (Network.peerType == NetworkPeerType.Server) {
if (Input.GetKey(KeyCode.UpArrow)) { constantForce.force.z = moveForce * forceMod ; constantForce.torque.x = moveTorque * forceMod;}
if (Input.GetKey(KeyCode.DownArrow)) { constantForce.force.z = -moveForce * forceMod; constantForce.torque.x = -moveTorque * forceMod;}
if (!Input.GetKey(KeyCode.UpArrow) !Input.GetKey(KeyCode.DownArrow)) { constantForce.force.z = 0; constantForce.torque.x = 0;}
if (Input.GetKey(KeyCode.LeftArrow)) { constantForce.force.x = -moveForce * forceMod; constantForce.torque.z = moveTorque * forceMod;}
if (Input.GetKey(KeyCode.RightArrow)) { constantForce.force.x = moveForce * forceMod; constantForce.torque.z = -moveTorque * forceMod;}
if (!Input.GetKey(KeyCode.LeftArrow) !Input.GetKey(KeyCode.RightArrow)) { constantForce.force.x = 0; constantForce.torque.z = 0;}
*/
//Client code
if(owner!=null Network.player==owner){
renderer.material = blueColor;
//Only the client that owns this object executes this code
var HInput : float = Input.GetAxis("Horizontal");
var VInput : float = Input.GetAxis("Vertical");
var JumpInput : float = Input.GetAxis("Jump");
//Is our input different? Do we need to update the server?
if(lastClientHInput!=HInput || lastClientVInput!=VInput || lastClientJumpInput!=JumpInput){
lastClientHInput = HInput;
lastClientVInput = VInput;
lastClientJumpInput = JumpInput;
if(Network.isServer){
//Too bad a server can't send an rpc to itself using "RPCMode.Server"!...bugged :[
SendMovementInput(HInput, VInput, JumpInput);
}else if(Network.isClient){
SendMovementInput(HInput, VInput, JumpInput); //Use this (and line 64) for simple "prediction"
networkView.RPC("SendMovementInput", RPCMode.Server, HInput, VInput, JumpInput);
}
}
}
if (Network.isClient) {
renderer.material = redColor;
}
//Server movement code
if(Network.isServer || Network.player==owner){//Also enable this on the client itself: "|| Network.player==owner){|"
//Actually move the player using his/her input
var moveDirection : Vector3 = new /*Vector3.Lerp( */Vector3(serverCurrentHInput, 0, serverCurrentVInput)/*, Vector3(clientCurrentHInput, 0, clientCurrentVInput), Time.time)*/;
constantForce.force.z = moveDirection.z * moveForce;
constantForce.force.x = moveDirection.x * moveForce;
constantForce.torque.z = moveDirection.x * -moveTorque;
constantForce.torque.x = moveDirection.z * moveTorque;
if (serverCurrentJumpInput > 0) {
if (jumps > 0 jumpTime < Time.time) {
rigidbody.velocity = (Vector3(rigidbody.velocity.x,jumpForce,rigidbody.velocity.z));
audio.Play();
jumps --;
jumpTime = Time.time + jumpInterval;
}
}
}
}
function OnTriggerEnter (other : Collider) {
jumps = 2;
jumpTime = 0.0;
}
@RPC
function SendMovementInput(HInput : float, VInput : float, JumpInput : float){
//Called on the server
serverCurrentHInput = HInput;
serverCurrentVInput = VInput;
serverCurrentJumpInput = JumpInput;
}
function GuessMovementInput(HInput : float, VInput : float){
//Called on the server
clientCurrentHInput = HInput;
clientCurrentVInput = VInput;
}