unity-decal

Before calling any skill in this module: if you are about to call a skill with parameters guessed from its name or description, STOP — read this file (or fetch its schema via GET /skills/recommend?includeSchema=true) first. If you already have the parameter definitions from recommend/schema, you may proceed straight to dryRun.

Triggers

• Adding decals in URP
• Configuring a Decal Projector
• Enabling the Decal Renderer Feature
• 在 URP 中添加贴花、配置 Decal Projector、启用 Decal Renderer Feature

Decal Skills

URP Decal Projector creation and configuration (URP only; HDRP decal APIs are not covered here).

Operating Mode

• Query skills (decal_get_info, decal_find_all) are SkillMode.SemiAuto — they run in all three modes without grant.
• Mutating skills (decal_create, decal_set_properties, decal_set_properties_batch, decal_ensure_renderer_feature) are SkillMode.FullAuto — under Approval they need user grant (grant triggers one server-side execute returning the result); under Auto / Bypass they execute directly.
• decal_delete carries SkillOperation.Delete and is auto-forbidden in Approval / Auto modes (NeverInSemi). Only Bypass or the user-managed Allowlist can run it.

URP Package Stub

This module is compiled against com.unity.render-pipelines.universal (URP). When URP is not installed, every skill returns a stub { error: "Universal Render Pipeline package … is not installed." } (RenderPipelineSkillsCommon.NoURP()). The stub is a diagnostic payload, not a permission denial — it does not require grant and is not treated as NeverInSemi.

Guardrails

Routing:

• For renderer feature management in general: urp
• For DecalProjector scene operations: this module

Runtime-first rules:

• Call decal_ensure_renderer_feature before assuming the current URP renderer is decal-ready
• Use decal_get_info / decal_find_all to discover real projector state before editing
• decal_set_properties_batch expects items to be a JSON array string
• This module targets the URP Decal workflow first; do not assume HDRP decal APIs are covered here

Skills

decal_create

Create a Decal Projector.

Parameter	Type	Required	Default	Description
name	string	No	"Decal Projector"	Name of the new GameObject
materialPath	string	No	null	Decal material asset path; left unassigned when omitted
x	float	No	0	World position X
y	float	No	0	World position Y
z	float	No	0	World position Z

decal_get_info

Inspect a Decal Projector.

Parameter	Type	Required	Default	Description
name	string	No*	null	GameObject name
instanceId	int	No*	0	GameObject instance ID
path	string	No*	null	GameObject hierarchy path

* Supply at least one locator — an empty call is refused up front rather than reported as "not found".

decal_set_properties

Modify Decal Projector properties. Every property below is applied only when supplied, so a call changes exactly the fields you name; any invalid value rejects the whole call before anything is written.

Parameter	Type	Required	Default	Description
name	string	No*	null	GameObject name
instanceId	int	No*	0	GameObject instance ID
path	string	No*	null	GameObject hierarchy path
materialPath	string	No	null	Decal material asset path
drawDistance	float	No	null	Max distance at which the decal is drawn
fadeScale	float	No	null	Fraction of drawDistance at which fading starts
fadeFactor	float	No	null	Overall opacity multiplier
startAngleFade	float	No	null	Angle (degrees) where angle-based fading begins
endAngleFade	float	No	null	Angle (degrees) where angle-based fading completes
uvScale	string	No	null	UV tiling as "x,y"
uvBias	string	No	null	UV offset as "x,y"
size	string	No	null	Projector box size as "x,y,z"
pivot	string	No	null	Projector pivot offset as "x,y,z"
renderingLayerMask	uint	No	null	Rendering layer mask bits
scaleMode	string	No	null	ScaleInvariant or InheritFromHierarchy (other values, including bare numbers, are rejected)

decal_find_all

List Decal Projectors in the scene.

Parameter	Type	Required	Default	Description
limit	int	No	50	Max projectors returned

decal_delete

Delete a Decal Projector GameObject.

Parameter	Type	Required	Default	Description
name	string	No*	null	GameObject name
instanceId	int	No*	0	GameObject instance ID
path	string	No*	null	GameObject hierarchy path

decal_set_properties_batch

Batch-edit Decal Projectors.

Parameter	Type	Required	Default	Description
items	json string	Yes	-	JSON array of {name, instanceId, path, materialPath, drawDistance, fadeScale, fadeFactor, startAngleFade, endAngleFade, uvScale, uvBias, size, pivot, renderingLayerMask, scaleMode} — same per-item keys as decal_set_properties

decal_ensure_renderer_feature

Ensure the target URP renderer has a DecalRendererFeature.

Parameter	Type	Required	Default	Description
assetPath	string	No	null	URP asset path; the active URP asset is used when omitted
rendererIndex	int	No	-1	Renderer index within the URP asset; -1 selects the asset's default renderer
rendererDataPath	string	No	null	UniversalRendererData asset path — takes precedence over rendererIndex, and must belong to the resolved URP asset

Returns alreadyExists: true when the feature was already present, so the call is safe to repeat.

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Exact Signatures

Exact names, parameters, defaults, and returns are defined by GET /skills/schema or unity_skills.get_skill_schema(), not by this file.