Shader "Hidden/TerrainEngine/PaintHeightTool" { 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 kMaxHeight (32766.0f/65535.0f) 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 = 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)) * UnpackHeightmap(tex2D(_FilterTex, i.pcUV)); return PackHeightmap(clamp(height + BRUSH_STRENGTH * brushShape, 0, kMaxHeight)); } ENDCG } Pass // 1 stamp heights { Name "Stamp Heights" CGPROGRAM #pragma vertex vert #pragma fragment StampHeight #define STAMP_TOOL_MODE (_BrushParams[0]) // Min=0 | Set=1 | Max=2 #define HEIGHT_UNDER_CURSOR (_BrushParams[1]) #define BRUSH_STAMPHEIGHT (_BrushParams[2]) #define BLEND_AMOUNT (_BrushParams[3]) 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 = 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)) * UnpackHeightmap(tex2D(_FilterTex, i.pcUV)); float brushHeight = brushShape * BRUSH_STAMPHEIGHT; // smoothmax behavior float targetHeight; float brushIntersection = saturate(1.0f - brushShape); float brushSmooth = exp2(brushIntersection * 8.0f); targetHeight = SmoothMax(height, brushHeight, brushSmooth); // "preserve details = 0" stamp is an offset from the height under the cursor float flatHeight = lerp(height, HEIGHT_UNDER_CURSOR + BRUSH_STAMPHEIGHT, brushShape); // composite results float outheight = lerp(flatHeight, targetHeight, BLEND_AMOUNT); if (STAMP_TOOL_MODE != 2) { outheight = lerp(min(height, outheight), max(height, outheight), STAMP_TOOL_MODE); } return PackHeightmap(clamp(outheight, 0.0f, kMaxHeight)); } ENDCG } Pass // 2 set height (flatten) { Name "Set Heights" CGPROGRAM #pragma vertex vert #pragma fragment SetHeight /*============================================================================ NOTE(wyatt): use SetExactHeight.shader instead ============================================================================*/ float4 SetHeight(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 = BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)) * UnpackHeightmap(tex2D(_FilterTex, i.pcUV)); // 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 _SmoothWeights; // centered, min, max, unused float4 SmoothHeight(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 = BRUSH_STRENGTH * oob * UnpackHeightmap(tex2D(_BrushTex, brushUV)) * UnpackHeightmap(tex2D(_FilterTex, i.pcUV)); 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; float3 new_height = float3(h, min(h, height), max(h, height)); h = dot(new_height, _SmoothWeights.xyz); 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)) * UnpackHeightmap(tex2D(_FilterTex, i.pcUV)); float alphaMap = tex2D(_MainTex, i.pcUV).r; return ApplyBrush(alphaMap, brushStrength); } ENDCG } Pass // 5 paint holes { Name "Paint Holes" CGPROGRAM #pragma vertex vert #pragma fragment PaintHoles float4 PaintHoles(v2f i) : SV_Target { float2 brushUV = PaintContextUVToBrushUV(i.pcUV); float holes = tex2D(_MainTex, i.pcUV).r; float brush = UnpackHeightmap(tex2D(_BrushTex, brushUV)); float filter = UnpackHeightmap(tex2D(_FilterTex, i.pcUV)); // out of bounds multiplier float oob = all(saturate(brushUV) == brushUV) ? 1.0f : 0.0f; float brushStrength = BRUSH_STRENGTH * oob; float val = brush * filter; // filter could be negative. need to account for this val = abs(val) > (1 - abs(brushStrength)) && abs(val) > .0001f ? sign(brushStrength) * sign(val) : 0.0f; holes += val; return holes; } ENDCG } } Fallback Off }