// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt) Shader "Procedural Worlds/GeNa/PaintHeight" { Properties { _MainTex ("Texture", any) = "" {} } SubShader { ZTest Always Cull Off ZWrite Off CGINCLUDE #include "UnityCG.cginc" #include "TerrainTool.cginc" sampler2D _MainTex; float4 _MainTex_TexelSize; // 1/width, 1/height, width, height sampler2D _BrushTex; float4 _BrushParams; #define BRUSH_STRENGTH (_BrushParams[0]) #define BRUSH_TARGETHEIGHT (_BrushParams[1]) #define BRUSH_STAMPHEIGHT (_BrushParams[2]) 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; } float ApplyBrush(float height, float brushStrength) { float targetHeight = BRUSH_TARGETHEIGHT; if (targetHeight > height) { height += brushStrength; height = height < targetHeight ? height : targetHeight; } else { height -= brushStrength; height = height > targetHeight ? height : targetHeight; } return height; } ENDCG Pass // 0 raise/lower heights { Name "Raise/Lower Heights" CGPROGRAM #pragma vertex vert #pragma fragment RaiseHeight float4 RaiseHeight(v2f i) : SV_Target { float2 brushUV = PaintContextUVToBrushUV(i.pcUV); float2 heightmapUV = PaintContextUVToHeightmapUV(i.pcUV); // out of bounds multiplier float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f; float height = UnpackHeightmap(tex2D(_MainTex, heightmapUV)); float brushShape = oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)); return PackHeightmap(clamp(height + BRUSH_STRENGTH * brushShape, 0, 0.5f)); } ENDCG } Pass // 1 stamp heights { Name "Stamp Heights" CGPROGRAM #pragma vertex vert #pragma fragment StampHeight float SmoothMax(float a, float b, float p) { // calculates a smooth maximum of a and b, using an intersection power p // higher powers produce sharper intersections, approaching max() return log2(exp2(a * p) + exp2(b * p) - 1.0f) / p; } float4 StampHeight(v2f i) : SV_Target { float2 brushUV = PaintContextUVToBrushUV(i.pcUV); float2 heightmapUV = PaintContextUVToHeightmapUV(i.pcUV); // out of bounds multiplier float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f; float height = UnpackHeightmap(tex2D(_MainTex, heightmapUV)); float brushShape = oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)); float brushHeight = brushShape * BRUSH_STAMPHEIGHT; float brushIntersection = saturate(1.0f - BRUSH_STRENGTH * 100.0f); // convert to 0..1 range, then invert float targetHeight; // = max(height, brushHeight); { // TODO: get rid of this hack to convert brush strength into a smooth factor -- make this an explicit control instead float brushSmooth = exp2(brushIntersection * 8.0f); targetHeight = SmoothMax(height, brushHeight, brushSmooth); } targetHeight = clamp(targetHeight, 0.0f, 0.5f); // Keep in valid range (0..0.5f) height = targetHeight; // lerp(height, targetHeight, brushOpacity); // TODO: do we want to obey actual opacity as well? return PackHeightmap(height); } ENDCG } Pass // 2 set height (flatten) { Name "Set Heights" CGPROGRAM #pragma vertex vert #pragma fragment SetHeight float4 SetHeight(v2f i) : SV_Target { float2 brushUV = PaintContextUVToBrushUV(i.pcUV); float2 heightmapUV = PaintContextUVToHeightmapUV(i.pcUV); // out of bounds multiplier float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f; float height = UnpackHeightmap(tex2D(_MainTex, heightmapUV)); float brushStrength = BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)); // smooth set 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(height); } ENDCG } Pass // 3 smooth terrain { Name "Smooth Heights" CGPROGRAM #pragma vertex vert #pragma fragment SmoothHeight float4 SmoothHeight(v2f i) : SV_Target { float2 brushUV = PaintContextUVToBrushUV(i.pcUV); float2 heightmapUV = PaintContextUVToHeightmapUV(i.pcUV); // out of bounds multiplier float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f; float height = UnpackHeightmap(tex2D(_MainTex, heightmapUV)); float brushStrength = BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)); float h = 0.0F; float xoffset = _MainTex_TexelSize.x; float yoffset = _MainTex_TexelSize.y; // 3*3 filter h += height; h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(xoffset, 0))); h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(-xoffset, 0))); h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(xoffset, yoffset))) * 0.75F; h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(-xoffset, yoffset))) * 0.75F; h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(xoffset, -yoffset))) * 0.75F; h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(-xoffset, -yoffset))) * 0.75F; h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(0, yoffset))); h += UnpackHeightmap(tex2D(_MainTex, heightmapUV + float2(0, -yoffset))); h /= 8.0F; return PackHeightmap(lerp(height, h, brushStrength)); } ENDCG } Pass // 4 paint splat alphamap { Name "Paint Texture" CGPROGRAM #pragma vertex vert #pragma fragment PaintSplatAlphamap float4 PaintSplatAlphamap(v2f i) : SV_Target { float2 brushUV = PaintContextUVToBrushUV(i.pcUV); // out of bounds multiplier float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f; float brushStrength = BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)); float alphaMap = tex2D(_MainTex, i.pcUV).r; return ApplyBrush(alphaMap, brushStrength); } ENDCG } } Fallback Off }