Impostors: dilate baked textures

4 files changed, 68 insertions, 3 deletions

diff --git a/3ner.cginc b/3ner.cginc
index 2452262..a6900d3 100644
--- a/3ner.cginc
+++ b/3ner.cginc
@@ -273,6 +273,11 @@ float4 frag(v2f i, uint facing : SV_IsFrontFace) : SV_Target {
   i.normal *= facing ? 1 : -1;
 
   Pbr pbr = getPbr(i);
+
+#if defined(_IMPOSTORS)
+  i.normal = pbr.normal;
+#endif
+
 #if defined(_DEBUG_VIEW_UNLIT)
   return pbr.albedo;
 #elif defined(_DEBUG_VIEW_WORLD_SPACE_NORMALS)
diff --git a/Scripts/Impostors.cs b/Scripts/Impostors.cs
index 30b06f6..ffd32b4 100644
--- a/Scripts/Impostors.cs
+++ b/Scripts/Impostors.cs
@@ -287,6 +287,56 @@ public class Impostors : MonoBehaviour
     }
   }
 
+  void DilateTexture(Texture2D tex, Texture2D alphaSource, bool preserveAlpha = false, int iterations = 8)
+  {
+    int w = tex.width, h = tex.height;
+    Color[] pixels = tex.GetPixels();
+    Color[] alpha = alphaSource.GetPixels();
+    Color[] origAlpha = preserveAlpha ? (Color[])alpha.Clone() : null;
+    Color[] buffer = (Color[])pixels.Clone();
+
+    int[] dx = { -1, 1, 0, 0 };
+    int[] dy = { 0, 0, -1, 1 };
+
+    for (int iter = 0; iter < iterations; iter++)
+    {
+      for (int y = 0; y < h; y++)
+      {
+        for (int x = 0; x < w; x++)
+        {
+          int i = y * w + x;
+          if (alpha[i].a > 0.01f) continue;
+
+          Color sum = Color.clear;
+          int count = 0;
+          for (int d = 0; d < 4; d++)
+          {
+            int nx = x + dx[d], ny = y + dy[d];
+            if (nx < 0 || nx >= w || ny < 0 || ny >= h) continue;
+            int ni = ny * w + nx;
+            if (alpha[ni].a > 0.01f || (iter > 0 && pixels[ni].a > 0))
+            {
+              sum += pixels[ni];
+              count++;
+            }
+          }
+          if (count > 0)
+          {
+            buffer[i] = sum / count;
+            buffer[i].a = 1;
+          }
+        }
+      }
+      var tmp = pixels; pixels = buffer; buffer = tmp;
+    }
+
+    if (preserveAlpha)
+      for (int i = 0; i < pixels.Length; i++) pixels[i].a = origAlpha[i].a;
+
+    tex.SetPixels(pixels);
+    tex.Apply();
+  }
+
   void SaveAndConfigureTexture(Texture2D atlas, TextureExportSettings settings, string baseName, out string path)
   {
     path = Path.Combine(OutputFolder, $"{baseName}_{settings.suffix}.{(settings.isEXR ? "exr" : "png")}");
@@ -332,6 +382,11 @@ public class Impostors : MonoBehaviour
       (new TextureExportSettings("depth", isEXR: true, mipmaps: false, sRGB: false, filter: FilterMode.Bilinear, uncompressed: true), "_Impostors_Depth_Atlas")
     };
 
+    // Dilate RGB to prevent dark halos from texture filtering
+    DilateTexture(albedoAtlas, albedoAtlas, preserveAlpha: true);
+    DilateTexture(normalAtlas, albedoAtlas);
+    DilateTexture(metallicGlossAtlas, albedoAtlas);
+
     Texture2D[] atlases = { albedoAtlas, normalAtlas, metallicGlossAtlas, depthAtlas };
     string[] paths = new string[exportSettings.Length];
     for (int i = 0; i < exportSettings.Length; i++)
diff --git a/impostor.cginc b/impostor.cginc
index f271612..1623681 100644
--- a/impostor.cginc
+++ b/impostor.cginc
@@ -105,8 +105,13 @@ ImpostorSample SampleImpostorCell(float2 cell, float3 frameDir, float3 pivotToCa
 ImpostorSample BlendImpostorSamples(ImpostorSample s00, ImpostorSample s01, ImpostorSample s10, ImpostorSample s11, float4 bw) {
     ImpostorSample result;
     result.albedo = s00.albedo * bw.x + s01.albedo * bw.y + s10.albedo * bw.z + s11.albedo * bw.w;
-    result.normal = s00.normal * bw.x + s01.normal * bw.y + s10.normal * bw.z + s11.normal * bw.w;
-    result.metallicGloss = s00.metallicGloss * bw.x + s01.metallicGloss * bw.y + s10.metallicGloss * bw.z + s11.metallicGloss * bw.w;
+
+    // Weight normal/metallicGloss by alpha to avoid blending with transparent (zero) pixels
+    float4 alphaBw = float4(s00.albedo.a, s01.albedo.a, s10.albedo.a, s11.albedo.a) * bw;
+    alphaBw /= max(dot(alphaBw, 1), 0.001);
+
+    result.normal = s00.normal * alphaBw.x + s01.normal * alphaBw.y + s10.normal * alphaBw.z + s11.normal * alphaBw.w;
+    result.metallicGloss = s00.metallicGloss * alphaBw.x + s01.metallicGloss * alphaBw.y + s10.metallicGloss * alphaBw.z + s11.metallicGloss * alphaBw.w;
     return result;
 }
 
diff --git a/pbr.cginc b/pbr.cginc
index a1df361..6a14655 100644
--- a/pbr.cginc
+++ b/pbr.cginc
@@ -165,7 +165,7 @@ Pbr getPbr(v2f i) {
   pbr.albedo = imp.albedo * _Color;
   pbr.normal = imp.normal;
   pbr.smoothness = imp.smoothness;
-  pbr.metallic = imp.metallic * _Metallic;
+  pbr.metallic = imp.metallic;
 #else
   pbr.albedo = _MainTex.Sample(aniso16_trilinear_repeat_s, uv_parallax * _MainTex_ST.xy + _MainTex_ST.zw);
   pbr.albedo *= _Color;