cam_pos      = [0.578916, 0.596023, -0.00614699]';
cam_dir      = [0.823589, 0.416329, 0.38519]';
cam_up       = [-0.561135, 0.49914, 0.660293]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.109905, 1.01074, -0.857455]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;