shader code 温度云图(温场)实现

Shader "Custom/TemperatureField" {
Properties {
_MainTex ("Base (RGB)", 2D) = "white" {}
_Point1("Temperature1",Range(0,100)) = 50
_Point2("Temperature2",Range(0,100)) = 50
_Point3("Temperature3",Range(0,100)) = 50
_Point4("Temperature4",Range(0,100)) = 50
}
SubShader {
AlphaTest Greater 0.1
pass
{
CGPROGRAM
// Upgrade NOTE: excluded shader from DX11, Xbox360, OpenGL ES 2.0 because it uses unsized arrays
#pragma exclude_renderers d3d11 xbox360 gles
#pragma target 3.0
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"


sampler2D _MainTex;
float4 _MainTex_ST;
float _Point1;
float _Point2;
float _Point3;
float _Point4;
bool computer = false;


struct v2f {
float4 pos:SV_POSITION;
float2 uv:TEXCOORD0;
};

v2f vert(appdata_base v)
{
v2f o;
o.pos=mul(UNITY_MATRIX_MVP,v.vertex);
o.uv = TRANSFORM_TEX(v.texcoord,_MainTex);
return o;
}

float computerTemperature(float2 uv)
{
int plength = 3;
float _midPointX[3] = {0.2,0.8,0.5};
float _midPointY[3] = {0.7,0.9,0.4};
float _midPointT[3] = {10,20,90};

float d1 = sqrt(uv.x*uv.x+uv.y*uv.y);
float d2 = sqrt((1-uv.x)*(1-uv.x)+(1-uv.y)*(1-uv.y));
float d3 = sqrt(uv.x*uv.x+(1-uv.y)*(1-uv.y));
float d4 = sqrt((1-uv.x)*(1-uv.x)+uv.y*uv.y);


float m = 1/d1+1/d2+1/d3+1/d4;
float n = 1/d1*_Point1+1/d2*_Point4+1/d3*_Point3+1/d4*_Point2;
for (int i = 0 ; i < plength ; i++)
{
float dp = sqrt((uv.x-_midPointX)*(uv.x-_midPointX)+(uv.y-_midPointY)*(uv.y-_midPointY));

m = m + 1/dp;
n = n + 1/dp*_midPointT;
}


return n/m;

}

float4 frag(v2f i):COLOR
{

float4 outp;

float4 texCol = tex2D(_MainTex,i.uv);

float temp = computerTemperature(i.uv);
//float temp = computeArray(i.uv);

//图像区域，判定设置为颜色的A > 0.5,输出为材质颜色+光亮值
if(texCol.w>0.5)
{
if(temp >= 60)
outp = float4(1,0,0,1)*(temp-60)/40+float4(1,1,0,1)*(1-(temp-60)/40);
else if(temp >= 30)
outp = float4(1,1,0,1)*(temp-30)/30+float4(0,1,0,1)*(1-(temp-30)/30);
else
outp = float4(0,1,0,1)*(temp)/30+float4(0,0,1,1)*(1-(temp)/30);
}
else
outp = float4(0,0,0,0);
return outp;
}

ENDCG
}
}
FallBack "Diffuse"
}