fix(terrain shadows): fix brightened lods

[doodlum]

Summary by CodeRabbit

• Bug Fixes
  • Adjusted terrain shadow calculation to use the raw terrain shadow value instead of a fixed blend, improving consistency and perceived depth.
  • Users may notice more accurate shading on terrain surfaces, with better contrast and fewer washed-out areas in complex lighting.
  • Change applies only when terrain shadows are enabled; other lighting and shadow systems are unaffected.

[coderabbitai]

Walkthrough

Replaced the lerp-based terrain shadow mix with a direct assignment in GetWorldShadow when TERRAIN_SHADOWS is defined, returning the raw TerrainShadows::GetTerrainShadow(...) value instead of lerp(..., 1.0, 0.1). No other logic, declarations, or control-flow structures were changed.

Changes

Cohort / File(s)	Summary
Shadow sampling logic update package/Shaders/Common/ShadowSampling.hlsli	Inside GetWorldShadow under TERRAIN_SHADOWS, replaced lerp(TerrainShadows::GetTerrainShadow(...), 1.0, 0.1) with direct TerrainShadows::GetTerrainShadow(...). Removed fixed 0.1 blend; now returns raw terrain shadow.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• alandtse

Poem

Thump-thump goes my coder’s heart at night,
Shadows now pure, unblended light.
No lerpy swirl, just truth in shade—
A rabbit’s hop, a cleaner grade.
From grass to peak the value flows,
Raw as the moon on my twitchy nose. 🐇🌙

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title Check	✅ Passed	The title succinctly summarizes the primary change of correcting overly bright terrain shadow LODs and uses a clear conventional commit style without extraneous details.
Docstring Coverage	✅ Passed	No functions found in the changes. Docstring coverage check skipped.

✨ Finishing touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch terrain-shadow-fix

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Reviewing files that changed from the base of the PR and between 92f0f66 and 8936b05.

📒 Files selected for processing (1)

• package/Shaders/Common/ShadowSampling.hlsli (1 hunks)

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📓 Path-based instructions (1)

**/*.{cpp,cxx,cc,c,h,hpp,hxx,hlsl,hlsli,fx,fxh,py}

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Files:

• package/Shaders/Common/ShadowSampling.hlsli

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🔇 Additional comments (1)

package/Shaders/Common/ShadowSampling.hlsli (1)

152-152: LGTM! This correctly fixes the artificial brightening of terrain shadows.

The previous lerp(TerrainShadows::GetTerrainShadow(...), 1.0, 0.1) was computing shadow * 0.9 + 0.1, which clamped the minimum shadow value to 0.1 (brightening shadowed areas) and reduced maximum brightness to 0.9. By returning the raw terrain shadow value, this change restores proper shadow darkness and addresses the "brightened lods" issue mentioned in the PR title.

The downstream usage in GetEffectShadow (line 170: min(worldShadow, shadow)) and GetWaterShadow (line 192: worldShadow * shadow) will correctly handle the more accurate shadow values.

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[github-actions]

Using provided base ref: 92f0f66
Using base ref: 92f0f66
Base commit date: 2025-10-06T10:10:35+01:00 (Monday, October 06, 2025 10:10 AM)
No actionable suggestions for changed features.

[github-actions]

✅ A pre-release build is available for this PR:
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