cam_pos      = [-0.541698, 1.40105, 1.75094]';
cam_dir      = [0.992362, 0.0931081, -0.0809182]';
cam_up       = [-0.0857198, 0.992207, 0.0904297]';
cam_lookat   = [0, 0, 1]';
cam_sky      = [0, 1, 0]';
cam_right    = [-0.117981, 0.110128, -1.32017]';
cam_fpoint   = [0, 0, 1]';
cam_angle    = 90;