/decal

name: unity-decal
description: Create and configure URP Decal Projectors

> **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.

| 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` |

`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