add annotation:normalmatrix is the modevl face direction
add annotation:normalmatrix is the modevl face direction

wjingzhe/OpenGL_SB5_static,wjingzhe/OpenGL_SB5_static,wjingzhe/OpenGL_SB5_static,wjingzhe/OpenGL_SB5_static,wjingzhe/OpenGL_SB5_static