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fix(terrain shadows): fix compiler warnings #1798

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Merged
doodlum merged 2 commits into from
Feb 1, 2026
Merged

fix(terrain shadows): fix compiler warnings #1798

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fix(terrain shadows): fix compiler warnings
doodlum Feb 1, 2026
98a12ce
Merge branch 'dev' into terain-shadow-compile-pls
doodlum Feb 1, 2026
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18 changes: 4 additions & 14 deletions features/Terrain Shadows/Shaders/TerrainShadows/TerrainShadows.hlsli
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Original file line number Diff line number Diff line change
Expand Up @@ -19,19 +19,9 @@ namespace TerrainShadows

float GetTerrainShadow(const float3 worldPos, SamplerState samp)
{
if (SharedData::terraOccSettings.EnableTerrainShadow) {
float2 terraOccUV = GetTerrainShadowUV(worldPos.xy);
float2 shadowHeight = GetTerrainZ(ShadowHeightTexture.SampleLevel(samp, terraOccUV, 0));
#if defined(DEFERRED)
// Sharp shadows
float shadowFraction = saturate(10.0 * (worldPos.z - shadowHeight.y) / (shadowHeight.x - shadowHeight.y));
#else
// Blurry shadows to simulate scattering
float shadowFraction = saturate((worldPos.z - shadowHeight.y) / (shadowHeight.x - shadowHeight.y));
#endif
return shadowFraction;
}

return 1.0;
if (!SharedData::terraOccSettings.EnableTerrainShadow)
return 1.0;
float2 shadowHeight = GetTerrainZ(ShadowHeightTexture.SampleLevel(samp, GetTerrainShadowUV(worldPos.xy), 0));
return saturate((worldPos.z - shadowHeight.y) / (shadowHeight.x - shadowHeight.y));;
Comment on lines +22 to +25

@coderabbitai coderabbitai Bot Feb 1, 2026

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⚠️ Potential issue | 🟠 Major

🧩 Analysis chain

🏁 Script executed:

find . -type f -name "*.hlsli" -o -name "*.hlsl" | head -20

Repository: doodlum/skyrim-community-shaders

Length of output: 1417

🏁 Script executed:

find . -type f -path "*TerrainShadows*" | head -20

Repository: doodlum/skyrim-community-shaders

Length of output: 346

🏁 Script executed:

find . -type f -name "*.hlsli" | xargs rg "GetTerrainZ" -A 5 -B 2

Repository: doodlum/skyrim-community-shaders

Length of output: 3742

🏁 Script executed:

cat "./features/Terrain Shadows/Shaders/TerrainShadows/TerrainShadows.hlsli"

Repository: doodlum/skyrim-community-shaders

Length of output: 896

🏁 Script executed:

rg "GetTerrainZ" -A 10 -B 2

Repository: doodlum/skyrim-community-shaders

Length of output: 2057

🏁 Script executed:

rg "ZRange" -A 2 -B 2

Repository: doodlum/skyrim-community-shaders

Length of output: 4817

🏁 Script executed:

rg "terraOccSettings" -l

Repository: doodlum/skyrim-community-shaders

Length of output: 184

🏁 Script executed:

cat "src/Features/TerrainShadows.cpp" | head -100

Repository: doodlum/skyrim-community-shaders

Length of output: 3188

🏁 Script executed:

cat "src/Features/TerrainShadows.h"

Repository: doodlum/skyrim-community-shaders

Length of output: 3178

🏁 Script executed:

rg "max.*1e-5|max.*1e-6|max.*epsilon" -t hlsl -t hlsli

Repository: doodlum/skyrim-community-shaders

Length of output: 104

🏁 Script executed:

rg "shadowHeight|ZRange.y - ZRange.x" -A 3 -B 1

Repository: doodlum/skyrim-community-shaders

Length of output: 3406

🏁 Script executed:

cat "features/Terrain Shadows/Shaders/TerrainShadows/ShadowUpdate.cs.hlsl" | grep -A 5 -B 5 "ZRange.y - ZRange.x"

Repository: doodlum/skyrim-community-shaders

Length of output: 545

🏁 Script executed:

rg "divide.*zero|guard.*division|epsilon.*1e-" -i

Repository: doodlum/skyrim-community-shaders

Length of output: 1260

🏁 Script executed:

grep -r "Math.hlsli\|EPSILON_DIVISION" "features/Terrain Shadows/Shaders/TerrainShadows/"

Repository: doodlum/skyrim-community-shaders

Length of output: 58

🏁 Script executed:

cat "package/Shaders/Common/Math.hlsli" | grep -A 2 "EPSILON"

Repository: doodlum/skyrim-community-shaders

Length of output: 304

Guard against a zero terrain shadow range.

If shadowHeight.x == shadowHeight.y, the division yields NaN and saturate won't recover. Add an epsilon guard to prevent division by zero.

🛡️ Suggested guard 
-    float2 shadowHeight = GetTerrainZ(ShadowHeightTexture.SampleLevel(samp, GetTerrainShadowUV(worldPos.xy), 0));
-    return saturate((worldPos.z - shadowHeight.y) / (shadowHeight.x - shadowHeight.y));;
+    float2 shadowHeight = GetTerrainZ(ShadowHeightTexture.SampleLevel(samp, GetTerrainShadowUV(worldPos.xy), 0));
+    float denom = max(shadowHeight.x - shadowHeight.y, 1e-5);
+    return saturate((worldPos.z - shadowHeight.y) / denom);
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
if (!SharedData::terraOccSettings.EnableTerrainShadow)
return 1.0;
float2 shadowHeight = GetTerrainZ(ShadowHeightTexture.SampleLevel(samp, GetTerrainShadowUV(worldPos.xy), 0));
return saturate((worldPos.z - shadowHeight.y) / (shadowHeight.x - shadowHeight.y));;
if (!SharedData::terraOccSettings.EnableTerrainShadow)
return 1.0;
float2 shadowHeight = GetTerrainZ(ShadowHeightTexture.SampleLevel(samp, GetTerrainShadowUV(worldPos.xy), 0));
float denom = max(shadowHeight.x - shadowHeight.y, 1e-5);
return saturate((worldPos.z - shadowHeight.y) / denom);
🤖 Prompt for AI Agents 
In `@features/Terrain` Shadows/Shaders/TerrainShadows/TerrainShadows.hlsli around
lines 22 - 25, The code can divide by zero when shadowHeight.x equals
shadowHeight.y; in the terrain shadow computation (look for
SharedData::terraOccSettings.EnableTerrainShadow, GetTerrainZ,
ShadowHeightTexture.SampleLevel, GetTerrainShadowUV, and the final saturate call
using worldPos.z), add a small epsilon guard: compute the range as
(shadowHeight.x - shadowHeight.y), replace the division with worldPos.z minus
shadowHeight.y divided by max(range, epsilon) (or early-return a safe value like
1.0 when range is zero) so the saturate call never receives NaN.

}
}