sample: add additional lights in KageBall

[sindharta]

No description provided.

[Copilot]

Pull request overview

This PR updates the URP toon shader’s shadow “tweak” computation to use a shared helper function, and adjusts the KageBall sample scene lighting by grouping lights under a new root and adding a shadow-casting point light.

Changes:

• Add a TweakShadow(...) helper and replace duplicated _SystemShadowsLevel_var logic with calls to it.
• Update additional-light shadow handling in the shading grade map path (Forward+ path updated; non-Forward+ path partially updated).
• Update the KageBall sample scene hierarchy by adding a Lights root and adding a Point Light.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
com.unity.toonshader/Samples~/URP/Scenes/KageBall/KageBall.unity	Adds a Lights parent object and a new point light in the sample scene.
com.unity.toonshader/Runtime/UniversalRP/Shaders/UniversalToonBodyShadingGradeMap.hlsl	Refactors shadow tweak calculation to use TweakShadow (but leaves one additional-light path inconsistent).
com.unity.toonshader/Runtime/UniversalRP/Shaders/UniversalToonBodyDoubleShadeWithFeather.hlsl	Refactors shadow tweak calculation to use TweakShadow consistently for main/additional lights.
com.unity.toonshader/Runtime/UniversalRP/Shaders/UniversalToonBody.hlsl	Adds TweakShadow and updates additional light retrieval to use the 3-arg GetAdditionalLight overload.

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[Copilot]

In the non-Forward+ additional lights loop, tweakShadows is set to additionalLight.shadowAttenuation directly, while the Forward+ path (and main light) now uses TweakShadow(...). This makes shadow response differ depending on whether Forward+ is enabled. Use the same TweakShadow(additionalLight.shadowAttenuation) logic here as well (or intentionally keep raw attenuation in both paths).

Suggested change

	float tweakShadows = additionalLight.shadowAttenuation;
	float tweakShadows = TweakShadow(additionalLight.shadowAttenuation);

[Copilot]

TweakShadow is replacing the previous inline _SystemShadowsLevel_var calculation, but it is not equivalent: the old logic clamped values <= 0.001 down to 0.0001, while max(..., 0.001) clamps them up to 0.001. If the goal is a refactor without changing visual output, update TweakShadow to preserve the prior threshold/floor behavior (or document that the minimum shadow tweak has changed).

Suggested change

	return max((shadow * 0.5) + 0.5 + _Tweak_SystemShadowsLevel, 0.001);
	float tweakedShadow = (shadow * 0.5) + 0.5 + _Tweak_SystemShadowsLevel;
	return (tweakedShadow <= 0.001) ? 0.0001 : tweakedShadow;

[Copilot]

shadowMask is introduced to call the 3-arg GetAdditionalLight overload, but it’s declared as a scalar float. URP’s API commonly expects a half4 shadow mask (from baked GI / shadowmask mixing), and using a scalar here relies on implicit splat conversion and makes it harder to later thread through a real shadow mask. Consider changing this to a half4 (e.g., all-ones) and/or plumbing the actual shadow mask from InputData where available.

Suggested change

	const float shadowMask = 1;
	const half4 shadowMask = half4(1.0h, 1.0h, 1.0h, 1.0h);