Iphone

im programming some OpenGL effect in c++.

I want to explode my grenade, and the frags must go in a random (or anything alike) direction.

Problem is that i must generate as many possible random numbers in less time possible. So the 3D direction of the particles are random.

How can I get the fragments/particles going from the center of the grenade to any random direction? Usage of the function rand() causes the fragments to go in 4 directions or so.

Iphone

z = drand48()*2-1;
r = drand48()*2*pi;
x = cos(r);
y = sin(r);
r = sqrt(x*x+y*y+z*z);
x /= r;
y /= r;
z /= r;
should have been
z = drand48()*2-1;
r = drand48()*2*pi;
x = cos(r);
y = sin(r);
r = sqrt(1-z*z);
x *= r;
y *= r;