Skipping a Ball Across Water

Unity Engine
1

I have 2 planes one with a grass texture and one with water. I am trying to skip the ball across the water. I am not sure the best way to achieve this. Should I add a upward force on trigger with water? I wrote a script that sort of works but not well. The problem I am having is every bounce on water the ball goes higher. Any one know of any better ways to do this.

#pragma strict
var noOfHitsOnWater : int;					// Number of times ball hits the water
var ahhhhSound : AudioClip;					// ahhh Sound Played when ball stops on water

function Start () {

}

function OnCollisionEnter(other : Collision) {
	if (other.gameObject.tag == "water"){
			rigidbody.AddForce(Vector3.up * other.relativeVelocity.magnitude * 100);
			noOfHitsOnWater ++;
//			rigidbody.AddForce (0,1000,0);
//		if(rigidbody.velocity.magnitude == 0){
//			transform.position = RayCasterJS.hitPosition;
//		}
}
	if (other.gameObject.tag == "Course"){
			noOfHitsOnWater = 0;
		}
}

function OnCollisionExit(other: Collision){

}


function Update () {
	if(noOfHitsOnWater >= 4){
		transform.position = RayCasterJS.hitPosition;
		audio.PlayOneShot(ahhhhSound);														// Play sound
		rigidbody.velocity = Vector3(0,0,0);
		noOfHitsOnWater = 0;
		}
}

Thanks For Any Help You Can Provide
Brandon

2

I would just separate the Up and Forward velocities and lerp them to 0 over time, probably with some specific damping for each direction. ( ball would lose speed and altitude, probably not at the same rate ).

So, once your force is supplied, use something like “rigidbody.velocity = Vector3.Lerp(rigidbody.velocity,newVelocityWithDampingEffects,Time)”

where newVelocityWithDampingEffects is a vector3 where the relative up and forward values are also lerped to 0.

3

I am not sure I understand. Would it look like this

var newVelocityWithDampingEffects : Vector3;
var Time : float;

function OnCollisionEnter(other : Collision) {
	if (other.gameObject.tag == "water"){
			rigidbody.velocity = Vector3.Lerp(rigidbody.velocity,newVelocityWithDampingEffects,Time);
}
}

I set the newVelocityWithDampingEffects to have a Y = 10 but I am not seeing any upward force being applied.

Thanks for all the help.

4

Not exactly, that will not have time to lerp as it will only be called when a collision occurs.

I would start a co-routine when you enter a collision, which applies the initial upwards force, then yields until another collision.( probably using a bool ). The coroutine will do the actual lerping as it would be called continuously. I’m not on a dev pc at the minute so I can’t really provide much concrete examples, also I write in C#. But…

function OnCollisionEnter(other : Collision) {
	if (other.gameObject.tag == "water"){
                        collided = true;
			StartCoroutine(bounce());
}

IEnumerator bounce()
{
   collided = false;

   while(!collided)
   {
       rigidbody.velocity = Vector3.Lerp(rigidbody.velocity,newVelocityWithDampingEffects,Time);
       yield return null;

   }
}

That’s generally what I meant. Obviously there are problems with this (e.g. bounce routine will possibly not exit a loop if the collided flag is not reset on a previous frame ). There are many ways around this but I just wanted to show you the general idea.

5

Why not on Collision stay? Or Maybe On Trigger?

function OnCollisionStay(other : Collision) {
	if (other.gameObject.tag == "water"){
			rigidbody.velocity = Vector3.Lerp(rigidbody.velocity,newVelocityWithDampingEffects,Time);

Thanks