首先需要根据医院提供的数据生成Texture3D,然后在shader中使用内置函数tex3D进行3D纹理采样，最后通过lightCT封装的算法过滤颜色通道，只取单个通道。shader代码如下，效果如图。
Shader "Custom/CT" { Properties { _Volume ("Texture3D", 3D) = "" {} _WindowWidth("WindowWidth",float) = 2000 _WindowPos("NarrowPos",float) = 1000 maxDataValue("DataMax",float) = 2000 minDataValue("DataMin",float) = 0 } SubShader { Tags { "RenderType"="Opaque" "Queue" = "Geometry" } LOD 100 //ZWrite Off //ZTest Off Pass { CGPROGRAM #pragma vertex vert #pragma fragment frag #include "UnityCG.cginc" #pragma multi_compile _ WHOLE sampler3D _Volume; float minDataValue; float maxDataValue; float _WindowWidth; float _WindowPos; float lightCT(float a){ float minV = saturate((_WindowPos - (_WindowWidth / 2) - minDataValue ) / (maxDataValue - minDataValue)); float maxV = saturate((_WindowPos + (_WindowWidth / 2) - minDataValue ) / (maxDataValue - minDataValue)); return saturate((a - minV)/(maxV - minV)); } struct appdata { float4 vertex : POSITION; }; struct v2f { float4 vertex : SV_POSITION; float3 worldPos : TEXCOORD0; }; v2f vert (appdata v) { v2f o; o.vertex = UnityObjectToClipPos(v.vertex); o.worldPos = v.vertex; return o; } fixed4 frag (v2f i) : SV_Target { float4 col = float4(0, 0, 0, 0); float3 lpos =i.worldPos; float3 pos =float3(lpos.x, lpos.y , lpos.z+0.5);//做成屏幕特效的坐标调整 col = tex3D(_Volume, float4(pos, 0));//采样3D纹理 col.r = lightCT(col.r); //CT图像生成算法过滤，此处取任意一个通道即可 return float4(col.rrr,1); } ENDCG } } }