Spherical mapping

frag.glsl

// from inear
http://www.inear.se/2011/09/set-a-sphere-on-fire-with-three-js/

float PI = 3.14159265;
float TWOPI = 6.28318531;
float BaseRadius = 1.0;

vec3 sphere( float u, float v) {

	u *= PI;
	v *= TWOPI;
	vec3 pSphere;

	pSphere.x = BaseRadius * cos(v) * sin(u);
	pSphere.y = BaseRadius * sin(v) * sin(u);
	pSphere.z = BaseRadius * cos(u);

	return pSphere;
}