public static float r_distance(vec3 a,vec3 b){
  float x=a.m[0] - b.m[0];
  float y=a.m[1] - b.m[1];
  float z=a.m[2] - b.m[2];
  float result=(float)Math.sqrt(x * x + y * y + z * z);
  return result;
}

public static float r_distance ( vec3 a , vec3 b ) { float x = a . m [ 0 ] - b . m [ 0 ] ; float y = a . m [ 1 ] - b . m [ 1 ] ; float z = a . m [ 2 ] - b . m [ 2 ] ; float result = ( float ) Math . sqrt ( x * x + y * y + z * z ) ; return result ; }
\ brief distance ( vec3 a , vec3 b )
