Unity将4个纹理图拼接成1个纹理

需要的效果

最终实现的效果大概如下:
在这里插入图片描述

4个贴图上去

这里随便放一个切分的图。
在这里插入图片描述

Shader代码如下

直接上代码:

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

// Unlit shader. Simplest possible textured shader.
// - no lighting
// - no lightmap support
// - no per-material color

Shader "Unlit/TextureMy" {
Properties {
    _MainTex ("Base (RGB)", 2D) = "white" {}
    _MainTex0 ("Base0 (RGB)", 2D) = "white" {}
    _MainTex1 ("Base1 (RGB)", 2D) = "white" {}
    _MainTex2 ("Base2 (RGB)", 2D) = "white" {}
    _MainTex3 ("Base3 (RGB)", 2D) = "white" {}
}

SubShader {
    Tags { "RenderType"="Opaque" }
    LOD 100

    Pass {
        CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma target 2.0
            #pragma multi_compile_fog

            #include "UnityCG.cginc"

            struct appdata_t {
                float4 vertex : POSITION;
                float2 texcoord : TEXCOORD0;
                UNITY_VERTEX_INPUT_INSTANCE_ID
            };

            struct v2f {
                float4 vertex : SV_POSITION;
                float2 texcoord : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                UNITY_VERTEX_OUTPUT_STEREO
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
            sampler2D _MainTex0;
            sampler2D _MainTex1;
            sampler2D _MainTex2;
            sampler2D _MainTex3;

            v2f vert (appdata_t v)
            {
                v2f o;
                UNITY_SETUP_INSTANCE_ID(v);
                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
                UNITY_TRANSFER_FOG(o,o.vertex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 col;
                float2 uv = i.texcoord;
                float2 uvFix = uv;
                
                if (uv.x < 0.5)
                {
                    if(uv.y < 0.5)
                    {
                        uvFix.x = uv.x * 2;
                        uvFix.y = uv.y * 2;
                        col = tex2D (_MainTex2 , uvFix );
                    }
                    else
                    {
                        uvFix.x = uv.x * 2;
                        uvFix.y = uv.y * 2 - 1;
                        col = tex2D (_MainTex0 , uvFix );                    
                    }
                }
                else
                {
                    if(uv.y < 0.5)
                    {
                        uvFix.x = uv.x * 2 - 1;
                        uvFix.y = uv.y * 2 ;
                        col = tex2D (_MainTex3 , uvFix );
                    }
                    else
                    {
                        uvFix.x = uv.x * 2 - 1;
                        uvFix.y = uv.y * 2 - 1;
                        col = tex2D (_MainTex1 , uvFix );                    
                    }
                }
                //fixed4 col = tex2D(_MainTex, i.texcoord);
                UNITY_APPLY_FOG(i.fogCoord, col);
                UNITY_OPAQUE_ALPHA(col.a);
                return col;
            }
        ENDCG
    }
}

}