setFromEuler method
Set Quant using Euler equation
Implementation
Quat setFromEuler(double x, double y, double z){
var c1 = math.cos( x * 0.5 );
var c2 = math.cos( y * 0.5 );
var c3 = math.cos( z * 0.5 );
var s1 = math.sin( x * 0.5 );
var s2 = math.sin( y * 0.5 );
var s3 = math.sin( z * 0.5 );
// XYZ
this.x = s1 * c2 * c3 + c1 * s2 * s3;
this.y = c1 * s2 * c3 - s1 * c2 * s3;
this.z = c1 * c2 * s3 + s1 * s2 * c3;
w = c1 * c2 * c3 - s1 * s2 * s3;
return this;
}