Mesh normals shader example in the Built-In Render Pipeline
Example of a shader that renders mesh normals as colors.
読み終わるまでの所要時間 2 分最終更新 1ヶ月前
重要
The Built-In Render Pipeline is deprecated and will be made obsolete in a future release.
It remains supported, including bug fixes and maintenance, through the full Unity 6.7 LTS lifecycle.
For more information on migration, refer to Migrating from the Built-In Render Pipeline to the Universal Render Pipeline and Render pipeline feature comparison.
A cat-like character rendered with different colors that represent the direction each surface faces.
Shader "Unlit/WorldSpaceNormals"{ // no Properties block this time! SubShader { Pass { HLSLPROGRAM #pragma vertex vert #pragma fragment frag // include file that contains UnityObjectToWorldNormal helper function #include "UnityCG.cginc" struct v2f { // we'll output world space normal as one of regular ("texcoord") interpolators half3 worldNormal : TEXCOORD0; float4 pos : SV_POSITION; }; // vertex shader: takes object space normal as input too v2f vert (float4 vertex : POSITION, float3 normal : NORMAL) { v2f o; o.pos = UnityObjectToClipPos(vertex); // UnityCG.cginc file contains function to transform // normal from object to world space, use that o.worldNormal = UnityObjectToWorldNormal(normal); return o; } half4 frag (v2f i) : SV_Target { half4 c = 0; // normal is a 3D vector with xyz components; in -1..1 // range. To display it as color, bring the range into 0..1 // and put into red, green, blue components c.rgb = i.worldNormal*0.5+0.5; return c; } ENDHLSL } }}
Besides resulting in pretty colors, normals are used for all sorts of graphics effects -- lighting, reflections, silhouettes and so on.
In the shader above, we started using one of Unity's built-in shader include files. Here, UnityCG.cginc was used which contains a handy function UnityObjectToWorldNormal. We have also used the utility function UnityObjectToClipPos, which transforms the vertex from object space to the screen. This just makes the code easier to read and is more efficient under certain circumstances.
We've seen that data can be passed from the vertex into fragment shader in so-called "interpolators" (or sometimes called "varyings"). In HLSL shading language they are typically labeled with TEXCOORDn semantic, and each of them can be up to a 4-component vector (see Input vertex data into a shader page for details).
Also we've learned a simple technique in how to visualize normalized vectors (in -1.0 to +1.0 range) as colors: just multiply them by half and add half. For more vertex data visualization examples, see Visualizaing vertex data.