Shader 時間

_Time float4 Time (t/20, t, t*2, t*3), use to animate things inside the shaders.
_SinTime float4 Sine of time: (t/8, t/4, t/2, t).
_CosTime float4 Cosine of time: (t/8, t/4, t/2, t).
unity_DeltaTime float4 Delta time: (dt, 1/dt, smoothDt, 1/smoothDt).
 _Time.x = time / 20
 _Time.y = time
 _Time.z = time * 2
 _Time.w = time * 3