fix(image based lighting): fixed planar reflection with IBL

[Dlizzio]

IBL textures now work with LOD water reflections.

Summary by CodeRabbit

• New Features

  • Improved reflection rendering: added a dedicated reflections prepass to ensure image-based lighting (IBL) textures are correctly bound during reflection passes (e.g., water LOD reflections).
  • Centralized IBL texture binding for more consistent visuals across reflection and prepass phases.

• Refactor

  • Internal restructuring to consolidate reflection-related logic without changing visible behavior.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

📝 Walkthrough

Walkthrough

Renames IBL::EarlyPrepass() to IBL::ReflectionsPrepass() and moves pixel-shader SRV binding (four IBL textures) into the renamed method. Header signature updated to ReflectionsPrepass(). No other behavioral changes; minor end-of-file newline formatting adjusted.

Changes

Cohort / File(s)	Summary
IBL header src/Features/IBL.h	Replaced virtual void EarlyPrepass() override; with virtual void ReflectionsPrepass() override;.
IBL implementation src/Features/IBL.cpp	Renamed EarlyPrepass() → ReflectionsPrepass() and moved PS shader SRV binding for diffuseIBLTexture, diffuseSkyIBLTexture, staticDiffuseIBLTexture, staticSpecularIBLTexture (bound to PS slot 76) into that method. Minor EOF newline formatting change.

Sequence Diagram(s)

(Note: skipped — changes are a rename and localized relocation of binding logic; no new multi-component control flow requiring a diagram.)

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• feat(ibl): lerp sky ibl using skylighting #1519: Modifies IBL prepass/reflections flow and PS SRV bindings for the same IBL textures.
• fix(ibl): add ibl to reflection normalization #1528: Adjusts IBL texture bindings and shader-stage/register usage for the same SRVs.

Suggested reviewers

• doodlum
• alandtse

Poem

🐰 I hopped through code with careful sniff,
Renamed a pass and moved a riff,
Four textures bound, all neat in place,
Reflections ready, smooth their grace,
A rabbit's nod, then off I skiff.

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title references a fix for planar reflection with IBL, which aligns with the PR's objective of making IBL textures work with LOD water reflections and the refactoring to use ReflectionsPrepass.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing touches

• 📝 Generate docstrings

---

---

📜 Recent review details

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Review profile: CHILL

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📥 Commits

Reviewing files that changed from the base of the PR and between a96f122 and 6ed1319.

📒 Files selected for processing (2)

• src/Features/IBL.cpp
• src/Features/IBL.h

🚧 Files skipped from review as they are similar to previous changes (1)

• src/Features/IBL.h

🧰 Additional context used

📓 Path-based instructions (3)

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

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

Do not include TODO/FIXME placeholders; provide complete, working solutions

Files:

• src/Features/IBL.cpp

src/**/*.{cpp,cxx,cc,h,hpp,hxx}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

src/**/*.{cpp,cxx,cc,h,hpp,hxx}: Ensure SE/AE/VR runtime compatibility; use runtime detection patterns (e.g., REL::RelocateMember())
Include robust error handling and resource management with graceful degradation in the plugin code

Files:

• src/Features/IBL.cpp

**/*

⚙️ CodeRabbit configuration file

**/*: When reviewing PRs, please provide suggestions for:

1. Conventional Commit Titles (if not following https://www.conventionalcommits.org/ or
   if the existing title does not describe the code changes):
   Format: type(scope): description
   Length: 50 characters limit for title, 72 for body
   Style: lowercase description, no ending period
   Examples:

   • feat(vr): add cross-eye sampling
   • fix(water): resolve flowmap bug
   • docs: update shader documentation

2. Issue References (if PR fixes bugs or implements features):
   Suggest adding appropriate GitHub keywords:

   • "Fixes #123" or "Closes #123" for bug fixes
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   • "Related to #123" for partial implementations

Otherwise, use your standard review approach focusing on code quality.

Files:

• src/Features/IBL.cpp

🧠 Learnings (3)

📓 Common learnings

Learnt from: jiayev
Repo: doodlum/skyrim-community-shaders PR: 0
File: :0-0
Timestamp: 2025-08-03T18:37:19.690Z
Learning: ISReflectionsRayTracing.hlsl and ISWorldMap.hlsl in the skyrim-community-shaders repository are image-space post-processing shaders that perform color sampling and blending operations that need proper linear color space handling for the linear lighting system. ISReflectionsRayTracing handles screen-space reflections and should use conditional Color::IrradianceToLinear/Gamma conversions similar to ISCompositeLensFlareVolumetricLighting.hlsl. ISWorldMap performs 7x7 color accumulation that should be done in linear space similar to the pattern used in ISSAOComposite.hlsl.

Learnt from: alandtse
Repo: doodlum/skyrim-community-shaders PR: 0
File: :0-0
Timestamp: 2025-07-05T05:20:45.823Z
Learning: In the skyrim-community-shaders repository, file deletion error handling improvements that replace existence checks and try-catch blocks with std::filesystem::remove error-code-based approaches are considered bug fixes rather than refactoring, as they address inadequate error handling and misleading log messages.

📚 Learning: 2025-08-03T18:37:19.690Z

Learnt from: jiayev
Repo: doodlum/skyrim-community-shaders PR: 0
File: :0-0
Timestamp: 2025-08-03T18:37:19.690Z
Learning: ISReflectionsRayTracing.hlsl and ISWorldMap.hlsl in the skyrim-community-shaders repository are image-space post-processing shaders that perform color sampling and blending operations that need proper linear color space handling for the linear lighting system. ISReflectionsRayTracing handles screen-space reflections and should use conditional Color::IrradianceToLinear/Gamma conversions similar to ISCompositeLensFlareVolumetricLighting.hlsl. ISWorldMap performs 7x7 color accumulation that should be done in linear space similar to the pattern used in ISSAOComposite.hlsl.

Applied to files:

• src/Features/IBL.cpp

📚 Learning: 2025-06-17T05:40:22.785Z

Learnt from: alandtse
Repo: doodlum/skyrim-community-shaders PR: 577
File: features/Wetness Effects/Shaders/WetnessEffects/WetnessEffects.hlsli:57-61
Timestamp: 2025-06-17T05:40:22.785Z
Learning: Default parameter values are supported in the HLSL compiler used by the skyrim-community-shaders project, contrary to standard HLSL (FXC/DXC) limitations.

Applied to files:

• src/Features/IBL.cpp

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Build plugin and addons

🔇 Additional comments (2)

src/Features/IBL.cpp (2)

105-121: LGTM! Properly binds all IBL textures for planar reflections.

The addition of staticDiffuseIBLTexture and staticSpecularIBLTexture to the reflection prepass (4 SRVs vs. the 2 in the main Prepass()) correctly enables IBL for LOD water reflections. The loaded guard ensures textures are initialized before binding.

---

313-313: Minor end-of-file newline adjustment.

No functional impact.

_{✏️ Tip: You can disable this entire section by setting review_details to false in your review settings.}

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[github-actions]

Using provided base ref: f8aa7a2
Using base ref: f8aa7a2
Base commit date: 2026-01-13T15:11:17Z (Tuesday, January 13, 2026 03:11 PM)
No actionable suggestions for changed features.

[github-actions]

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

[coderabbitai]

Actionable comments posted: 0

Caution

Some comments are outside the diff and can’t be posted inline due to platform limitations.

⚠️ Outside diff range comments (1)

src/Features/IBL.cpp (1)

105-121: Add validation to SetShaderResourcesPS() to ensure all textures are properly initialized before dereferencing.

If SetupResources() returns early due to a DDS loading failure (lines 246, 256, 282, 292), the texture pointers may remain null even though loaded is true. Add null checks for diffuseIBLTexture, diffuseSkyIBLTexture, staticDiffuseIBLTexture, and staticSpecularIBLTexture before accessing their SRVs, or set loaded = false when initialization fails.

📜 Review details

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 0dc6997 and a96f122.

📒 Files selected for processing (2)

• src/Features/IBL.cpp
• src/Features/IBL.h

🧰 Additional context used

📓 Path-based instructions (3)

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

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

Do not include TODO/FIXME placeholders; provide complete, working solutions

Files:

• src/Features/IBL.h
• src/Features/IBL.cpp

src/**/*.{cpp,cxx,cc,h,hpp,hxx}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

src/**/*.{cpp,cxx,cc,h,hpp,hxx}: Ensure SE/AE/VR runtime compatibility; use runtime detection patterns (e.g., REL::RelocateMember())
Include robust error handling and resource management with graceful degradation in the plugin code

Files:

• src/Features/IBL.h
• src/Features/IBL.cpp

**/*

⚙️ CodeRabbit configuration file

**/*: When reviewing PRs, please provide suggestions for:

1. Conventional Commit Titles (if not following https://www.conventionalcommits.org/ or
   if the existing title does not describe the code changes):
   Format: type(scope): description
   Length: 50 characters limit for title, 72 for body
   Style: lowercase description, no ending period
   Examples:

   • feat(vr): add cross-eye sampling
   • fix(water): resolve flowmap bug
   • docs: update shader documentation

2. Issue References (if PR fixes bugs or implements features):
   Suggest adding appropriate GitHub keywords:

   • "Fixes #123" or "Closes #123" for bug fixes
   • "Implements #123" or "Addresses #123" for features
   • "Related to #123" for partial implementations

Otherwise, use your standard review approach focusing on code quality.

Files:

• src/Features/IBL.h
• src/Features/IBL.cpp

🧠 Learnings (3)

📓 Common learnings

Learnt from: jiayev
Repo: doodlum/skyrim-community-shaders PR: 0
File: :0-0
Timestamp: 2025-08-03T18:37:19.690Z
Learning: ISReflectionsRayTracing.hlsl and ISWorldMap.hlsl in the skyrim-community-shaders repository are image-space post-processing shaders that perform color sampling and blending operations that need proper linear color space handling for the linear lighting system. ISReflectionsRayTracing handles screen-space reflections and should use conditional Color::IrradianceToLinear/Gamma conversions similar to ISCompositeLensFlareVolumetricLighting.hlsl. ISWorldMap performs 7x7 color accumulation that should be done in linear space similar to the pattern used in ISSAOComposite.hlsl.

Learnt from: alandtse
Repo: doodlum/skyrim-community-shaders PR: 0
File: :0-0
Timestamp: 2025-07-05T05:20:45.823Z
Learning: In the skyrim-community-shaders repository, file deletion error handling improvements that replace existence checks and try-catch blocks with std::filesystem::remove error-code-based approaches are considered bug fixes rather than refactoring, as they address inadequate error handling and misleading log messages.

Learnt from: ThePagi
Repo: doodlum/skyrim-community-shaders PR: 1369
File: src/Features/SnowCover.cpp:515-515
Timestamp: 2025-10-02T14:20:33.454Z
Learning: In the Community Shaders codebase (skyrim-community-shaders repository), hardcoded shader resource slot numbers are used directly in code rather than being defined as named constants. This is the established convention and should not be flagged as an issue.

Learnt from: jiayev
Repo: doodlum/skyrim-community-shaders PR: 0
File: :0-0
Timestamp: 2025-07-18T15:21:03.641Z
Learning: In the skyrim-community-shaders rendering pipeline, materials with alpha < 1 or alpha blending enabled are rendered in non-deferred mode rather than deferred mode. This means issues with dynamic cubemaps on transparent materials are actually non-deferred rendering issues.

Learnt from: CR
Repo: doodlum/skyrim-community-shaders PR: 0
File: .github/copilot-instructions.md:0-0
Timestamp: 2025-08-17T18:37:35.839Z
Learning: Applies to features/*/Shaders/**/*.{hlsl,hlsli,fx,fxh} : Avoid GPU register/buffer conflicts in HLSL; verify register usage (e.g., with hlslkit buffer scanning)

📚 Learning: 2025-08-03T18:37:19.690Z

Learnt from: jiayev
Repo: doodlum/skyrim-community-shaders PR: 0
File: :0-0
Timestamp: 2025-08-03T18:37:19.690Z
Learning: ISReflectionsRayTracing.hlsl and ISWorldMap.hlsl in the skyrim-community-shaders repository are image-space post-processing shaders that perform color sampling and blending operations that need proper linear color space handling for the linear lighting system. ISReflectionsRayTracing handles screen-space reflections and should use conditional Color::IrradianceToLinear/Gamma conversions similar to ISCompositeLensFlareVolumetricLighting.hlsl. ISWorldMap performs 7x7 color accumulation that should be done in linear space similar to the pattern used in ISSAOComposite.hlsl.

Applied to files:

• src/Features/IBL.h
• src/Features/IBL.cpp

📚 Learning: 2025-06-17T05:40:22.785Z

Learnt from: alandtse
Repo: doodlum/skyrim-community-shaders PR: 577
File: features/Wetness Effects/Shaders/WetnessEffects/WetnessEffects.hlsli:57-61
Timestamp: 2025-06-17T05:40:22.785Z
Learning: Default parameter values are supported in the HLSL compiler used by the skyrim-community-shaders project, contrary to standard HLSL (FXC/DXC) limitations.

Applied to files:

• src/Features/IBL.cpp

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (1)

• GitHub Check: Build plugin and addons

🔇 Additional comments (3)

src/Features/IBL.h (1)

38-45: LGTM!

The method declarations are well-organized: ReflectionsPrepass() correctly uses virtual and override to extend the base class prepass lifecycle, while SetShaderResourcesPS() is appropriately a non-virtual internal helper.

src/Features/IBL.cpp (2)

123-126: LGTM!

Clean refactoring that eliminates code duplication by delegating to the centralized SetShaderResourcesPS() helper.

---

128-133: I was unable to complete the verification requested in the original review comment due to repository access limitations. The original comment requests confirmation that ReflectionsPrepass() is declared as a virtual method in the base Feature class, but I cannot access the repository to verify this claim or confirm the validity of the SetShaderResourcesPS() call.

To complete this review, the following needs verification:

• Confirm ReflectionsPrepass() exists as a virtual method in the base Feature class
• Verify SetShaderResourcesPS() is accessible and valid in the IBL context
• Confirm the implementation approach is correct for binding IBL textures

_{✏️ Tip: You can disable this entire section by setting review_details to false in your review settings.}

[doodlum]

This does not address the actual problem. If the reflectionsprepass function does not work, then that function needs to be fixed. However, the game should never reset the shader resources bindings anyway.