Shader "Custom/twist" 
{

	SubShader 
	{
		Pass 
		{
			CGPROGRAM

			#pragma vertex vert 
			#pragma fragment frag 
			#include "unitycg.cginc"

			struct v2f 
			{
				float4 pos : POSITION;
				float4 color : COLOR0;
			};

			v2f vert(appdata_base v)
			{
				float angle = length(v.vertex) * _SinTime.w;
				//旋轉矩陣
				//float4x4  m =
				//{
				//	float4(cos(angle), 0, sin(angle), 0),
				//	float4(0, 1, 0, 0),
				//	float4(-sin(angle), 0, cos(angle), 0),
				//	float4(0, 0, 0, 1),
				//};

				//對旋轉矩陣進行優化計算,其實就是手動的進行旋轉矩陣的相乘的結果
				float x = cos(angle) * v.vertex.x + sin(angle) * v.vertex.z;
				float z = cos(angle) * v.vertex.z - sin(angle) * v.vertex.x;
				v.vertex.x = x;
				v.vertex.z = z;

				//v.vertex = mul(m, v.vertex);

				v2f o;
				o.pos = mul(UNITY_MATRIX_MVP, v.vertex);

				o.color = fixed4(0, 1, 1, 1);
				return o;
			}

			fixed4 frag(v2f IN) : COLOR 
			{
				return IN.color;
			}

			ENDCG
		}	
	}
	FallBack "Diffuse"
}
 

繼續改造程式碼，呈現一些不同的效果：

修改 22 行如下：

				float angle = length(v.vertex) * _Time.y;

float x = sin(angle) * v.vertex.x;