Rasagar/Library/PackageCache/com.unity.terrain-tools/Shaders/SetExactHeight.shader
2024-08-26 23:07:20 +03:00

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Shader "Hidden/TerrainTools/SetExactHeight" {
Properties { _MainTex ("Texture", any) = "" {} }
SubShader {
ZTest Always Cull Off ZWrite Off
CGINCLUDE
#include "UnityCG.cginc"
#include "Packages/com.unity.terrain-tools/Shaders/TerrainTools.hlsl"
sampler2D _MainTex;
float4 _MainTex_TexelSize; // 1/width, 1/height, width, height
sampler2D _BrushTex;
sampler2D _FilterTex;
float4 _BrushParams;
#define BRUSH_STRENGTH (_BrushParams[0])
#define BRUSH_TARGETHEIGHT (_BrushParams[1])
#define BRUSH_PINCHAMOUNT (_BrushParams[2])
#define BRUSH_ROTATION (_BrushParams[3])
struct appdata_t {
float4 vertex : POSITION;
float2 pcUV : TEXCOORD0;
};
struct v2f {
float4 vertex : SV_POSITION;
float2 pcUV : TEXCOORD0;
};
v2f vert(appdata_t v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.pcUV = v.pcUV;
return o;
}
ENDCG
Pass
{
Name "Set Exact Height"
CGPROGRAM
#pragma vertex vert
#pragma fragment SetExactHeight
float4 SetExactHeight(v2f i) : SV_Target
{
float2 brushUV = PaintContextUVToBrushUV(i.pcUV);
float2 heightmapUV = i.pcUV;
// out of bounds multiplier
float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f;
float height = UnpackHeightmap(tex2D(_MainTex, heightmapUV));
//float brushStrength = saturate(BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)));
float brushStrength = BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)) * UnpackHeightmap(tex2D(_FilterTex, i.pcUV));
float targetHeight = BRUSH_TARGETHEIGHT;
// have to do this check to ensure strength 0 == no change (code below makes a super tiny change even with strength 0)
if (brushStrength > 0.0f)
{
float deltaHeight = height - targetHeight;
// see https://www.desmos.com/calculator/880ka3lfkl
float p = saturate(brushStrength);
float w = (1.0f - p) / (p + 0.000001f);
// float w = (1.0f - p*p) / (p + 0.000001f); // alternative TODO test and compare
float fx = clamp(w * deltaHeight, -1.0f, 1.0f);
float g = fx * (0.5f * fx * sign(fx) - 1.0f);
deltaHeight = deltaHeight + g / w;
height = targetHeight + deltaHeight;
}
//return PackHeightmap(saturate(brushStrength) * targetHeight);
return PackHeightmap(lerp(height, targetHeight, brushStrength));
}
ENDCG
}
Pass
{
Name "Fill Height"
CGPROGRAM
#pragma vertex vert
#pragma fragment FillHeight
float4 FillHeight( v2f i ) : SV_Target
{
float oldHeight = UnpackHeightmap(tex2D(_MainTex, i.pcUV));
return PackHeightmap(lerp(oldHeight, BRUSH_TARGETHEIGHT, UnpackHeightmap(tex2D(_FilterTex, i.pcUV))));
}
ENDCG
}
}
Fallback Off
}