URP-利用矩阵在Shader中实现物体的平移和缩放

一、平移

方法一：

v.positionOS.xyz += _Translate.xyz;

方法二：

利用矩阵实现平移：

二、缩放

方法一：

v.positionOS.xyz *= _Scale.xyz*_Scale.w; _Scale.w实现全局缩放

方法二：

Shader"unity/Translation"
{
	Properties
	{
		_Color("Color",Color)=(0,0,0,0)
		_Translate("Translate",Vector)=(0,0,0,0)
		_Scale("Scale",Vector)=(1,1,1,1)
	 }

	SubShader
	{
		Tags
		{
			"RenderPipeline" = "UniversalPipeline"
		 }
		Pass
		{
			HLSLPROGRAM

			#pragma vertex vert
			#pragma fragment frag

			#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
			#include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Color.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Input.hlsl"

			CBUFFER_START(UnityPerMaterial)
			float4 _Color;
			float4 _Translate;
			float4 _Scale;
			CBUFFER_END

			struct Attributes
			{
				float4 positionOS : POSITION;
			 };

			struct Varyings
			{
				float4 positionCS : SV_POSITION;
			 };

			Varyings vert(Attributes v)
			{
				Varyings o = (Varyings)0;

				//平移
				// v.positionOS.xyz += _Translate.xyz;
				//平移矩阵
				float4x4 T = float4x4(
				 1,0,0,_Translate.x,
				 0,1,0,_Translate.y,
				 0,0,1,_Translate.z,
				 0,0,0,1
				 );

				v.positionOS = mul(T,v.positionOS);

				//缩放:将向量的每个分量分别与对应的缩放因子相乘
				//(v.positionOS.x,v.positionOS.y,v.positionOS.z) * (_Scale.x,_Scale.y,_Scale.z)
				//=(v.positionOS.x*Scale.x,v.positionOS.y*_Scale.y,v.positionOS.z*_Scale.z)
				// v.positionOS.xyz *= _Scale.xyz*_Scale.w;  _Scale.w实现全局缩放

				//缩放矩阵
				float3x3 Scale = float3x3(
				 _Scale.x,0,0,
				 0,_Scale.y,0,
				 0,0,_Scale.z
				 );

				v.positionOS.xyz = mul(Scale,v.positionOS.xyz)*_Scale.w;

				o.positionCS = TransformObjectToHClip(v.positionOS);
				return o;
			 }

			float4 frag(Varyings i):SV_Target
			{
				return _Color;
			 }

			ENDHLSL
		 }
	 }
 }