115 lines
3.0 KiB
Plaintext
115 lines
3.0 KiB
Plaintext
Shader "Hidden/TerrainTools/PaintAspect" {
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Properties{ _MainTex("Texture", any) = "" {} }
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SubShader{
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ZTest Always Cull Off ZWrite Off
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CGINCLUDE
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#include "UnityCG.cginc"
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#include "Packages/com.unity.terrain-tools/Shaders/TerrainTools.hlsl"
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sampler2D _MainTex;
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float4 _MainTex_TexelSize; // 1/width, 1/height, width, height
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sampler2D _BrushTex;
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sampler2D _Heightmap;
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sampler2D _AspectRemapTex;
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float4 _BrushParams;
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#define BRUSH_STRENGTH (_BrushParams[0])
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#define BRUSH_TARGETHEIGHT (_BrushParams[1])
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struct appdata_t {
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float4 vertex : POSITION;
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float2 pcUV : TEXCOORD0;
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};
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struct v2f {
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float4 vertex : SV_POSITION;
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float2 pcUV : TEXCOORD0;
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};
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v2f vert(appdata_t v)
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{
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v2f o;
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o.vertex = UnityObjectToClipPos(v.vertex);
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o.pcUV = v.pcUV;
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return o;
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}
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ENDCG
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Pass
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{
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Name "Paint Aspect"
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CGPROGRAM
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#pragma vertex vert
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#pragma fragment PaintSplatAlphamap
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#define HEIGHT_SAMPLE(__UV__) UnpackHeightmap(tex2D(_Heightmap, __UV__))
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float2 computeNormal(float2 uv, float epsilon)
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{
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float left = uv.x - epsilon;
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float right = uv.x + epsilon;
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float up = uv.y - epsilon;
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float down = uv.y + epsilon;
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float dzdx = ((HEIGHT_SAMPLE(float2(right, down)) + 2.0f * HEIGHT_SAMPLE(float2(right, uv.y)) + HEIGHT_SAMPLE(float2(right, up))) -
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(HEIGHT_SAMPLE(float2(left, down)) + 2.0f * HEIGHT_SAMPLE(float2(left, uv.y)) + HEIGHT_SAMPLE(float2(left, up)))) / 8.0f;
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float dzdy = ((HEIGHT_SAMPLE(float2(left, up)) + 2.0f * HEIGHT_SAMPLE(float2(uv.x, up)) + HEIGHT_SAMPLE(float2(right, up))) -
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(HEIGHT_SAMPLE(float2(left, down)) + 2.0f * HEIGHT_SAMPLE(float2(uv.x, down)) + HEIGHT_SAMPLE(float2(right, down)))) / 8.0f;
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return normalize(float2(dzdx, dzdy));
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}
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float4 _AspectValues;
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float GetAspectScale(float2 uv, float h)
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{
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float epsilon = _AspectValues[2] * _MainTex_TexelSize;
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float2 n = computeNormal(uv, epsilon);
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float aspect = saturate(dot(n, _AspectValues.xy));
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return tex2D(_AspectRemapTex, float2(aspect, 0.0f)).r;
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}
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float ApplyBrush(float height, float brushStrength)
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{
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float targetHeight = 1.0f;
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if (targetHeight > height)
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{
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height += brushStrength;
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height = height < targetHeight ? height : targetHeight;
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}
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else
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{
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height -= brushStrength;
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height = height > targetHeight ? height : targetHeight;
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}
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return height;
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}
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float4 PaintSplatAlphamap(v2f i) : SV_Target
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{
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float2 brushUV = PaintContextUVToBrushUV(i.pcUV);
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float2 normalUV = PaintContextUVToBrushUV(i.pcUV);
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// out of bounds multiplier
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float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f;
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float brushStrength = BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV.xy));
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float alphaMap = tex2D(_MainTex, i.pcUV).r;
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float h = UnpackHeightmap(tex2D(_Heightmap, i.pcUV));
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float targetAlpha = GetAspectScale(i.pcUV, h);
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return lerp(alphaMap, targetAlpha, brushStrength);
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}
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ENDCG
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}
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}
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Fallback Off
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} |