public function Raycast(origin, direction , radius, callback):Dynamic{
        // cube containing origin point
        var x = Math.floor(origin[0]);
        var y = Math.floor(origin[1]);
        var z = Math.floor(origin[2]);

        // break out direction vector
        var dx = direction[0];
        var dy = direction[1];
        var dz = direction[2];

        //direction to increment x,y,z when stepping
        var stepx = sign(dx);
        var stepy = sign(dy);
        var stepz = sign(dz);

        //The initial values depend on the fractional
        // part of the origin.
        var tMaxX = intbound(origin[0],dx);
        var tMaxy = intbound(origin[1],dy);
        var tMaxz = intbound(origin[2],dz);
        // the change in t when taking a step(always positive)
        var tDeltaX = stepx/dx;
        var tDeltaY = stepy/dy;
        var tDeltaz = stepz/dz;

        //buffer for face callback
        var face = new Vec3();

        //avoid infinite loop
        if (dx == 0 && dy == 0 && dz == 0){
            return ("test");
        }





    }