Draw a texture in a shader in URP

1. In the Properties block, replace the existing code with the

   _BaseMap

   property definition.

   Properties{    [MainTexture] _BaseMap("Base Map", 2D) = "white" {}}

   When you declare a texture property in the Properties block, Unity adds the

   _BaseMap

   property with the label Base Map to the Material, and adds the Tiling and the Offset controls.

   

   When you declare a property with the

   [MainTexture]

   attribute, Unity uses this property as the main texture of the Material.

   참고

   For compatibility reasons, the

   _MainTex

   property name is a reserved name. Unity uses a property with the name

   _MainTex

   as the main texture even it does not have the

   [MainTexture]

   attribute.

2. In

   struct Attributes

   and

   struct Varyings

   , add the

   uv

   variable for the UV coordinates on the texture:

   float2 uv           : TEXCOORD0;

3. Define the texture as a 2D texture and specify a sampler for it. Add the following lines before the CBUFFER block:

   TEXTURE2D(_BaseMap);SAMPLER(sampler_BaseMap);

   The TEXTURE2D and the SAMPLER macros are defined in one of the files referenced in

   Core.hlsl

   .
4. For tiling and offset to work, it's necessary to declare the texture property with the

   _ST

   suffix in the 'CBUFFER' block. The

   _ST

   suffix is necessary because some macros (for example,

   TRANSFORM_TEX

   ) use it.

   참고

   To ensure that the Unity shader is SRP Batcher compatible, declare all Material properties inside a single

   CBUFFER

   block with the name

   UnityPerMaterial

   . For more information on the SRP Batcher, refer to the documentation on the Scriptable Render Pipeline (SRP) Batcher.

   CBUFFER_START(UnityPerMaterial)    float4 _BaseMap_ST;CBUFFER_END

5. To apply the tiling and offset transformation, add the following line in the vertex shader:

   OUT.uv = TRANSFORM_TEX(IN.uv, _BaseMap);

   The

   TRANSFORM_TEX

   macro is defined in the

   Macros.hlsl

   file. The

   #include

   declaration contains a reference to that file.
6. In the fragment shader, use the

   SAMPLE_TEXTURE2D

   macro to sample the texture:

   half4 frag(Varyings IN) : SV_Target{    half4 color = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, IN.uv);    return color;}

// This shader draws a texture on the mesh.Shader "Example/URPUnlitShaderTexture"{    // The _BaseMap variable is visible in the Material's Inspector, as a field    // called Base Map.    Properties    {        [MainTexture] _BaseMap("Base Map", 2D) = "white" {}    }    SubShader    {        Tags { "RenderType" = "Opaque" "RenderPipeline" = "UniversalPipeline" }        Pass        {            HLSLPROGRAM            #pragma vertex vert            #pragma fragment frag            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"            struct Attributes            {                float4 positionOS   : POSITION;                // The uv variable contains the UV coordinate on the texture for the                // given vertex.                float2 uv           : TEXCOORD0;            };            struct Varyings            {                float4 positionHCS  : SV_POSITION;                // The uv variable contains the UV coordinate on the texture for the                // given vertex.                float2 uv           : TEXCOORD0;            };            // This macro declares _BaseMap as a Texture2D object.            TEXTURE2D(_BaseMap);            // This macro declares the sampler for the _BaseMap texture.            SAMPLER(sampler_BaseMap);            CBUFFER_START(UnityPerMaterial)                // The following line declares the _BaseMap_ST variable, so that you                // can use the _BaseMap variable in the fragment shader. The _ST                // suffix is necessary for the tiling and offset function to work.                float4 _BaseMap_ST;            CBUFFER_END            Varyings vert(Attributes IN)            {                Varyings OUT;                OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);                // The TRANSFORM_TEX macro performs the tiling and offset                // transformation.                OUT.uv = TRANSFORM_TEX(IN.uv, _BaseMap);                return OUT;            }            half4 frag(Varyings IN) : SV_Target            {                // The SAMPLE_TEXTURE2D marco samples the texture with the given                // sampler.                half4 color = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, IN.uv);                return color;            }            ENDHLSL        }    }}