8.空间变换

坐标系之间是用矩阵来进行变换的

            v2f vert(appdata v)
            {
                v2f o = (v2f)0;
                //o.pos= mul(UNITY_MATRIX_VP,mul(unity_ObjectToWorld,v.vertex));
                o.pos = UnityObjectToClipPos(v.vertex);
                return o;
            };