perf(emat): tweak fade and shadow intensity

[doodlum]

Summary by CodeRabbit

• New Features

  • Added a configurable shadow intensity parameter to extended materials.

• Improvements

  • More consistent shadow calculations across terrain, with simplified, uniform behavior.
  • Standardized step-count logic for rendering, improving stability and performance.
  • Extended-shadow behavior is enabled by default for a richer visual experience.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between d8e6735 and 911de7d.

📒 Files selected for processing (1)

• features/Extended Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli

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📝 Walkthrough

Walkthrough

Adds a public ShadowIntensity constant and simplifies Extended Materials shader shadow math (switches to squared-distance smoothstep bounds, fixes maxSteps to 16 with 4-step alignment, removes terrain-variation shadow branching), and enables ExtendShadows by default.

Changes

Cohort / File(s)	Summary
Shader Logic Updates features/Extended Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli	Adds static const float ShadowIntensity = 2.0;; replaces near/far with squared-distance (distSq) smoothstep range; forces maxSteps = 16, clamps and aligns numSteps to 4-step boundaries; simplifies shadow contribution to use ShadowIntensity, removing terrain-variation branching.
Default Configuration src/Features/ExtendedMaterials.h	Changes Settings::ExtendShadows default value from 0 to 1 (enable by default).

Sequence Diagram(s)

(omitted — changes are contained within shader and config; no multi-component sequential flow requiring visualization)

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• perf(Terrain Variation): feature rework, miplevel & sample optimisation #1224: Refactors terrain-variation shadow logic and shadow multiplier in the same ExtendedMaterials shader file.

Suggested reviewers

• alandtse
• davo0411
• doodlum

Poem

🐇✨ I hop through pixels, tracing light's soft dance,
A constant placed, old branches lose their chance,
Steps snap to four, neat rows beneath my paws,
Shadows measured squarely—no more claws,
My meadow glows, extended in my prance.

🚥 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 'perf(emat): tweak fade and shadow intensity' directly aligns with the changeset, which modifies fade calculations and shadow intensity constants/behavior in the Extended Materials shader.

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

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment
• Commit unit tests in branch emat-tweaks

📝 Coding Plan

• Generate coding plan for human review comments

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[github-actions]

No actionable suggestions for changed features.

[coderabbitai]

🤖 Fix all issues with AI agents

Verify each finding against the current code and only fix it if needed.


In `@features/Extended`
Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli:
- Around line 332-333: Replace the unusual scalar squaring pattern using
dot(distance, distance) with an explicit multiplication to improve clarity:
compute distSq by assigning distance * distance (affecting the variable distSq
used to compute nearBlendToFar via smoothstep) so the intent is obvious when
reading the code; update the expression where distSq is defined and leave the
subsequent nearBlendToFar and smoothstep usage unchanged.
- Around line 594-598: The preprocessor branching around TERRAIN_VARIATION is
redundant because both branches return the same expression; remove the
`#if/`#else/#endif block and replace it with a single return statement that
computes 1.0 - saturate(dot(max(0, sh - sh0), ShadowIntensity)) * quality
(referencing the existing variables sh, sh0, ShadowIntensity and quality) so the
function always uses that expression without conditional compilation.

🧹 Nitpick comments (2)

🤖 Fix all nitpicks with AI agents

Verify each finding against the current code and only fix it if needed.


In `@features/Extended`
Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli:
- Around line 332-333: Replace the unusual scalar squaring pattern using
dot(distance, distance) with an explicit multiplication to improve clarity:
compute distSq by assigning distance * distance (affecting the variable distSq
used to compute nearBlendToFar via smoothstep) so the intent is obvious when
reading the code; update the expression where distSq is defined and leave the
subsequent nearBlendToFar and smoothstep usage unchanged.
- Around line 594-598: The preprocessor branching around TERRAIN_VARIATION is
redundant because both branches return the same expression; remove the
`#if/`#else/#endif block and replace it with a single return statement that
computes 1.0 - saturate(dot(max(0, sh - sh0), ShadowIntensity)) * quality
(referencing the existing variables sh, sh0, ShadowIntensity and quality) so the
function always uses that expression without conditional compilation.

features/Extended Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli (2)

332-333: Nit: dot(distance, distance) is an unusual idiom for scalar squaring.

Since distance is a scalar float, dot(distance, distance) is functionally distance * distance but reads as if distance were a vector. Consider using distance * distance for clarity.

Suggested change

-	float distSq = dot(distance, distance);
+	float distSq = distance * distance;

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@features/Extended`
Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli around lines 332 -
333, Replace the unusual scalar squaring pattern using dot(distance, distance)
with an explicit multiplication to improve clarity: compute distSq by assigning
distance * distance (affecting the variable distSq used to compute
nearBlendToFar via smoothstep) so the intent is obvious when reading the code;
update the expression where distSq is defined and leave the subsequent
nearBlendToFar and smoothstep usage unchanged.

---

594-598: Redundant preprocessor branching — both TERRAIN_VARIATION paths are now identical.

Lines 595 and 597 produce the same expression. The #if defined(TERRAIN_VARIATION) / #else / #endif is dead branching that can be collapsed.

Suggested simplification

-#		if defined(TERRAIN_VARIATION)
-			return 1.0 - saturate(dot(max(0, sh - sh0), ShadowIntensity)) * quality;
-#		else
-			return 1.0 - saturate(dot(max(0, sh - sh0), ShadowIntensity)) * quality;
-#		endif
+			return 1.0 - saturate(dot(max(0, sh - sh0), ShadowIntensity)) * quality;

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@features/Extended`
Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli around lines 594 -
598, The preprocessor branching around TERRAIN_VARIATION is redundant because
both branches return the same expression; remove the `#if/`#else/#endif block and
replace it with a single return statement that computes 1.0 -
saturate(dot(max(0, sh - sh0), ShadowIntensity)) * quality (referencing the
existing variables sh, sh0, ShadowIntensity and quality) so the function always
uses that expression without conditional compilation.

[alandtse]

What are the impacts on terrain variation?

[github-actions]

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

[alandtse]

You're making some changes to the TV code including removing use of settings. What's the actual impact? Is the settings used anywhere else? Or is it dead code that should be removed?

[coderabbitai]

🧹 Nitpick comments (1)

features/Extended Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli (1)

22-22: Consider using project-preferred scalar constant style

Line 22 introduces a simple scalar shader constant as static const float. If you want consistency with existing repo style, switch this to a #define for scalar constants.

Style-aligned alternative

-	static const float ShadowIntensity = 2.0;
+#	define SHADOW_INTENSITY 2.0

Based on learnings: In the skyrim-community-shaders project, simple scalar constants in HLSL shaders use #define, while static const is used for more complex constants.

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@features/Extended`
Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli at line 22, Replace
the scalar shader constant declaration for ShadowIntensity (currently declared
as "static const float ShadowIntensity = 2.0;") with the project-preferred macro
form using `#define` (e.g., "#define ShadowIntensity 2.0") so it matches existing
HLSL style; ensure any float usage sites remain valid (use a float literal like
2.0 or 2.0f where required) and remove the old static const line (update any
surrounding comments if needed).

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@features/Extended`
Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli:
- Line 22: Replace the scalar shader constant declaration for ShadowIntensity
(currently declared as "static const float ShadowIntensity = 2.0;") with the
project-preferred macro form using `#define` (e.g., "#define ShadowIntensity 2.0")
so it matches existing HLSL style; ensure any float usage sites remain valid
(use a float literal like 2.0 or 2.0f where required) and remove the old static
const line (update any surrounding comments if needed).

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 47e053d0-0d66-451d-bd75-fe240f7d0765

📥 Commits

Reviewing files that changed from the base of the PR and between eff4cc9 and d8e6735.

📒 Files selected for processing (1)

• features/Extended Materials/Shaders/ExtendedMaterials/ExtendedMaterials.hlsli

[davo0411]

tv update will change how tv interracts with emat anyway