hallo. i got problems to fix my camera-math. i intended to assign the camera direction to the direction-vec of vehicle. n[0] = 0; n[1]=-1; n[2]=0; //origin dir of vehicle double dir[] = new double[3]; OM.transform(n,dir); //translated to current orientation matrix double ax = -dir[1]; //rotation axis double ay = dir[0]; double az = 0; double angle = Math.acos(dir[2]); Matrix3D Q = new Matrix3D(); //calculate a quaternion double w, x,y,z; w = Math.cos(angle/2); x = ax*Math.sin(-angle/2); y = ay*Math.sin(-angle/2); z = 0; Q.quaternion(w, x,y,z); camera.OM.setTransformation(Q); //setup camera matrix can someone help me? thanks.