cam_pos      = [-0.488703, 1.00932, 1.68889]';
cam_dir      = [0.968322, 0.228458, -0.100796]';
cam_up       = [-0.205086, 0.957901, 0.200913]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.189462, 0.231255, -1.29597]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;