Blink object on collision

Questions & Answers
1

I have a fish where the objective is to avoid Enemy fish. Now when the player fish hits the enemy fish i want the player fish to blink twice (n number if possible)

	void BlinkPlayer(int numBlink)
	{
		for(int i=0; i < numBlink; i++)
		{
			transform.renderer.enabled = false;
			StartCoroutine( Wait (.2f));
			transform.renderer.enabled = true;
			StartCoroutine( Wait (.2f));
		}
	}
	
	IEnumerator Wait(float seconds)
	{
		Debug.Log ("Wait");
		yield return new WaitForSeconds(seconds);	
	}

Then im calling BlinkPlayer() from OnCollisionEnter() Doesn’t matter how lrge value I give for Wait() my player fish doesn’t blink. I also tried taking out the for() loop inside BlinkPlayer(), but that didn’t work out either. Although it does print “Wait” in console.

Any idea what am I doing wrong? I am using unity 4.1 if that matters.

2

You’re close, but missing one crucial detail.

Unity’s docs say that StartCoroutine returns “immediately”. The function making the call doesn’t wait. It’s only the coroutine itself that waits.

You could probably re-organize it something like this:

void BlinkPlayer(int numBlinks) {
	StartCoroutine(DoBlinks(numBlinks, 0.2f));
}

IEnumerator DoBlinks(int numBlinks, float seconds) {
	for (int i=0; i<numBlinks*2; i++) {
	
		//toggle renderer
		renderer.enabled = !renderer.enabled;
		
		//wait for a bit
		yield return new WaitForSeconds(seconds);
	}
	
	//make sure renderer is enabled when we exit
	renderer.enabled = true;
}

Edit: It occurred to me that it might be easier to control the coroutine by duration (in seconds), as opposed to a fixed number of blinks. Something like this…

public class Blink : MonoBehaviour {
	void Start () {
		StartCoroutine(DoBlinks(3f, 0.2f));
	}
	
	IEnumerator DoBlinks(float duration, float blinkTime) {
		while (duration > 0f) {
				duration -= Time.deltaTime;
	 
	       //toggle renderer
	       renderer.enabled = !renderer.enabled;
	 
	       //wait for a bit
	       yield return new WaitForSeconds(blinkTime);
    	}
 
	    //make sure renderer is enabled when we exit
	    renderer.enabled = true;
	}
}