[Unity] 在 Shader 中使用 Texture Array 属性可以参考 https://catlikecod

制作一个创建 Texture Array 的工具

在代码中创建一个 Texture2DArray 变量，然后逐像素赋值

public Texture2D[] ordinaryTextures;
public GameObject objectToAddTextureTo;
private void CreateTextureArray()
{
    // Create Texture2DArray
    Texture2DArray texture2DArray = new
        Texture2DArray(ordinaryTextures[0].width,
        ordinaryTextures[0].height, ordinaryTextures.Length,
        TextureFormat.RGBA32, true, false);    // Apply settings
    texture2DArray.filterMode = FilterMode.Bilinear;
    texture2DArray.wrapMode = TextureWrapMode.Repeat;    // Loop through ordinary textures and copy pixels to the
    // Texture2DArray
    for (int i = 0; i < ordinaryTextures.Length; i++)
    {
        texture2DArray.SetPixels(ordinaryTextures[i].GetPixels(0),  
            i, 0);
    }    // Apply our changes
    texture2DArray.Apply();    // Set the texture to a material
    objectToAddTextureTo.GetComponent<Renderer>()
        .sharedMaterial.SetTexture("_MainTex", texture2DArray);
}

我觉得这个可以放到 Helper 里面

using UnityEngine;

namespace Universal
{
    public class MaterialHelper
    {
        /// <summary>
        /// All textures must have an identical width and height.
        /// </summary>
        /// <param name="ordinaryTextures"></param>
        /// <param name="objectToAddTextureTo"></param>
        public static void CreateTextureArray(Texture2D[] ordinaryTextures, GameObject objectToAddTextureTo)
        {
            // Create Texture2DArray
            Texture2DArray texture2DArray = new
                Texture2DArray(ordinaryTextures[0].width,
                    ordinaryTextures[0].height, ordinaryTextures.Length,
                    TextureFormat.RGBA32, true, false);    // Apply settings
            texture2DArray.filterMode = FilterMode.Bilinear;
            texture2DArray.wrapMode = TextureWrapMode.Repeat;    // Loop through ordinary textures and copy pixels to the
            // Texture2DArray
            for (int i = 0; i < ordinaryTextures.Length; i++)
            {
                texture2DArray.SetPixels(ordinaryTextures[i].GetPixels(0),  
                    i, 0);
            }    // Apply our changes
            texture2DArray.Apply();    // Set the texture to a material
            objectToAddTextureTo.GetComponent<Renderer>()
                .sharedMaterial.SetTexture("_MainTex", texture2DArray);
        }
    }
}

对于任意一个 mono，使用方法：

[Header("Material")] 

public Texture2D[] mapGridTextures;

private void Awake()
{
    MaterialHelper.CreateTextureArray(mapGridTextures, gameObject);
}

然后 shader 就使用默认的模板就好了

shader 的设置参考 catlikecoding.com/unity/tutor…

用例：在一个网格上，每一个格子的贴图是随机的

Shader "Unlit/UnlitGrid"
{
    Properties
    {
        _MainTex ("Main Texture Array", 2DArray) = "white" {}
        _GridTextureCount("Main Texture Array Length", int) = 1
        _RandSeed("Rand Seed", float) = 0
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 100

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            // make fog work
            #pragma multi_compile_fog

            #include "UnityCG.cginc"

            #pragma target 3.5
            
            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
                float4 worldSpacePos : TEXCOORD1;
            };

            UNITY_DECLARE_TEX2DARRAY(_MainTex);
            int _GridTextureCount;
            float _RandSeed;
            
            float4 _MainTex_ST;
            
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);

                o.worldSpacePos = mul(unity_ObjectToWorld, v.vertex);

                return o;
            }

            float PHI = 1.61803398874989484820459;  // Φ = Golden Ratio   

            float gold_noise(float2 xy){
                   return frac(tan(distance(xy*PHI, xy)*_RandSeed)*xy.x);
            }

            int random_range(float2 xy, int range)
            {
                float rand = gold_noise(xy);
                return clamp(floor(rand * range), 0, range - 1);
            }
            
            fixed4 frag (v2f i) : SV_Target
            {
                float2 st = i.worldSpacePos.xy / _GridSize;

                float2 ipos = floor(st);  // integer

                int rand = random_range(ipos, _GridTextureCount);
                
                fixed4 col = UNITY_SAMPLE_TEX2DARRAY(_MainTex, float3(i.uv, rand));
                
                // apply fog
                UNITY_APPLY_FOG(i.fogCoord, col);
                return col;
            }
            ENDCG
        }
    }
}

那么对于任意一个 mono，使用方法：

[Header("Material")] 

public Texture2D[] mapGridTextures;

private void Awake()
{
    MaterialHelper.CreateTextureArray(mapGridTextures, gameObject);
    render.material.SetInt("_GridTextureCount", mapGridTextures.Length);
    render.material.SetFloat("_RandSeed", Random.Range(1f, 100f));
}