Fix dot matrix shader.

[freezy]

Rewrite the dot shading function so it supports DXR. Also, ditch the emission fork which seems to work now and fixes the emission intensity.

[Copilot]

Pull Request Overview

This PR fixes DXR (DirectX Raytracing) support for the dot matrix display shader by rewriting the dot shading function to handle anti-aliasing differently in ray tracing vs raster contexts. It also removes an emission fork that was previously necessary but now works correctly.

• Adds DXR-safe anti-aliasing using UV feathering in ray tracing contexts instead of fwidth
• Updates all dot shape functions (Ellipse, RoundedRectangle, Rectangle) to use the new AAWidth helper
• Removes the HDRP_Emission custom function node that handled emission differently based on rendering pipeline

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
DotMatrixDisplayShader.hlsl	Implements AAWidth helper function and updates shape functions to support DXR
DotMatrixDisplayGraph.shadergraph	Removes emission fork node and updates shader graph connections

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[Copilot]

[nitpick] The magic number 0.75 should be defined as a named constant to improve maintainability and make it easier to tune.

Suggested change

	}
	// DXR-safe AA width helper: uses fwidth in raster, constant UV feather in ray tracing.
	// Scale factor for UV feathering in AAWidth. Tune as needed.
	static const float AA_UV_FEATHER_SCALE = 0.75;
	inline float AAWidth(float d, float2 dimensions)
	{
	#ifdef SHADER_STAGE_RAY_TRACING
	// Feather in UVs of a single dot cell. Tune the scale as needed.
	float uvFeather = max(1.0 / max(dimensions.x, dimensions.y), 1e-4) * AA_UV_FEATHER_SCALE;
	return uvFeather;
	#else
	return fwidth(d);
	#endif
	}

[Copilot]

[nitpick] The magic number 1e-4 should be defined as a named constant to improve code clarity and avoid potential floating-point precision issues.

Suggested change

	}
	// DXR-safe AA width helper: uses fwidth in raster, constant UV feather in ray tracing.
	// Minimum UV feather value to avoid floating-point precision issues
	static const float MIN_UV_FEATHER = 1e-4;
	inline float AAWidth(float d, float2 dimensions)
	{
	#ifdef SHADER_STAGE_RAY_TRACING
	// Feather in UVs of a single dot cell. Tune the scale as needed.
	float uvFeather = max(1.0 / max(dimensions.x, dimensions.y), MIN_UV_FEATHER) * 0.75;
	return uvFeather;
	#else
	return fwidth(d);
	#endif
	}