view_matrix.rotate_y(theta * (float)M_PI / 180);
view_matrix.rotate_x(phi * (float)M_PI / 180);
view_matrix.translate(Vec3(0, 0, -distance));
view_matrix.rotate_y(theta * (float)M_PI / 180);
view_matrix.rotate_x(phi * (float)M_PI / 180);
view_matrix.translate(Vec3(0, 0, -distance));