MaterialProcessor

Post-processor that upgrades imported materials from Unity's Standard shader to the Universal Render Pipeline (URP) Lit shader. Handles transparency and blend mode conversion for legacy rendering modes.

Definition

Namespace: Paragon.Editor.ThirdPartyPackageImporter Assembly: Paragon.Editor.dll

internal class MaterialProcessor : Processor

Inherits: Processor

Remarks

Third-party packages from the Unity Asset Store often use the Standard shader. This processor automatically upgrades them to URP/Lit using Unity's built-in MaterialUpgrader system, plus custom handling for transparency modes that the standard upgrader doesn't cover.

URP Upgraders

The static constructor uses reflection to access UniversalRenderPipelineMaterialUpgrader.GetUpgraders() (a non-public method) to get the full list of URP material upgraders. These are cached for all future upgrades.

Extended Upgrade: Transparency Modes

After the standard URP upgrade, ExtendedUpgrade checks the original material's _Mode property (Standard shader rendering mode):

Mode Value	Standard Mode	URP Conversion
0	Opaque	No extra work (handled by standard upgrader)
1	Cutout	_Surface=1, _AlphaClip=1, render queue 2450
2	Fade/Transparent	_Surface=1, _AlphaClip=1, _AlphaCutoff=0, SrcAlpha blending, render queue 3000

Item Filtering

• Skips local packages — returns empty for IsLocalPackage

• Filters to .mat files — only enabled, non-folder items with .mat extension (case-insensitive)

Quick Lookup

Goal	How
Upgrade runs automatically	Part of the PostProcessors pipeline
Target shader	Universal Render Pipeline/Lit
Source shader	Unity Standard (mode-based transparency)

Methods

OnProcess (protected override)

protected override IEnumerable<ImportPackageItem> OnProcess(ThirdPartyPackage package)

Returns enabled .mat items from the package. Returns empty for local packages.

OnProcessItem (protected override)

protected override void OnProcessItem(ImportPackageItem packageItem)

Loads the material, creates a copy of the original state, runs the URP upgrade, applies extended transparency handling, and marks dirty.

ExtendedUpgrade (private static)

private static void ExtendedUpgrade(Material material, Material oldMaterial)

Handles transparency mode conversion that the standard MaterialUpgrader doesn't cover. Only applies when the upgraded shader is Universal Render Pipeline/Lit.

Parameter	Type	Description
material	Material	The upgraded material (modified in-place)
oldMaterial	Material	Copy of the original material (read-only reference)

Static Fields

Field	Type	Access	Description
upgraders	List<MaterialUpgrader>	private static readonly	Cached list of URP material upgraders from Unity internals

Common Pitfalls

Reflection dependency on URP internals The static constructor accesses UniversalRenderPipelineMaterialUpgrader.GetUpgraders() via reflection. This internal method may change or be removed in future URP versions.

Material name overwrite OnProcessItem sets material.name to the file name (without extension). This overwrites any existing material name, which may differ from the file name if the material was renamed after creation.

Only handles Standard shader modes 0-2 The ExtendedUpgrade only handles _Mode values 0 (Opaque), 1 (Cutout), and 2 (Fade). Mode 3 (Transparent) is not explicitly handled and will use whatever the standard upgrader produces.

See Also

• PostProcessors Overview — post-processor subsystem

• FBXProcessor — renames materials in FBX files

• MetaProcessor — strips asset metadata