Bouncing Object losing velocity

Hello all!
First of all, let me say i'm a complete beginner in both Unity and Scripting, and please, excuse me if i make mistakes writing in english .

I've been doing some tutorials and now I'm learning C# in order to creat my own scripts.
When i make some progress or learn something, i just try to apply it to Unity, and one of those "efforts" is a very simple Arkanoid game.

Its' my second arkanoid clone, in the first one i managed speed and rebounds with code, in this one, i'm experimenting with Unity's physics.
I just add velocity to the rigid body, apply a bouncy material and edit it to get rid of the friction.
It works very well, with only one flaw. Sometimes...after a few collisions, it drops a lot of velocity (a few times to almost no speed at all).
Sometimes the speed loss is very small, but still noticeable, and i even saw a few times that the ball would gain a lot of speed (out of nowhere).

I saw a post here about a guy that was doing an "eternal bouncing ball" that had the same problem. His fix cannot be applied to mine, because the angles of the ball are constantly changing.

What i do is this:

Code (csharp):

1.  public float ballSpeed = 8;
2.      float xAngle = 5;
3.      float yAngle = 5;

And when i hit the space bar:

HTML:

void LaunchBall()
	{
		xAngle *= ballSpeed ;
		yAngle *= ballSpeed ;
		rigidbody.velocity =new Vector3 (xAngle, yAngle, 0);	
	}

I restrict the Z movement with a Configurable Joint, and after that...the ball bounces all the time, but as i tell you, sometimes it just don't work.

So, making a long story short, i would love to know what can i do to fix this.
I tried debugging the x and y angles, and are (of course) constantly changing and i can't figure out what step to do next.

I'll appreciate any help from more experienced people (and i have the feeling i'll be asking for advice here a lot ).

Thanks in advance!

Cheers.

Let me attach a test with that mechanic so you can see what i did wrong (I'm sorry some stuff like script names or folders are in spanish)
View attachment $Arkanoid Napi.rar

 

Hello,
I know This answer is somewhat late (2010 - 2013) but I just encounterred the same issue and fixed it by
1°) Launching the ball during the Start() (not very important here)
2°) Defining and attaching the physical materia with the following attributes


Attention this is still under UNITY V3.5 as I am planning to use my "won" Android License and they cannot be transferred to UNITY V4
I hope that this "modest" first contribution will help.

 

Had similar problem where my player dropped x-velocity when hitting floor. Added material ( friction: 0.001 bounciness: 0) to relevant floor colliders which solved problem. (friction = 0 gives you ice).