---
name: Collision Proxy
slug: collision-proxy
category: Automation
description: Collision Proxy authoring for game physics and blocking volumes in Blender via MCP. Use it to build simple collider meshes, convex hulls, capsules, and engine-specific UCX/UHX naming.
github: "https://github.com/arjun988/blender-skills/tree/main/.claude/skills/collision-proxy"
language: TypeScript
stars: 170
forks: 8
install: "npx degit https://github.com/arjun988/blender-skills/tree/main/.claude/skills/collision-proxy ~/.claude/skills/collision-proxy"
installs_to: ~/.claude/skills/collision-proxy
source_path: .claude/skills/collision-proxy/SKILL.md
collection_size: 25
category_size: 2109
collection_url: "https://dirskills.com/collections/arjun988/blender-skills"
added: 2026-09-07T05:22:29.277Z
last_synced: 2026-09-07T05:22:29.277Z
canonical_url: "https://dirskills.com/skills/collision-proxy"
---

# Collision Proxy

Collision Proxy authoring for game physics and blocking volumes in Blender via MCP. Use it to build simple collider meshes, convex hulls, capsules, and engine-specific UCX/UHX naming.

**Install:**

```bash
npx degit https://github.com/arjun988/blender-skills/tree/main/.claude/skills/collision-proxy ~/.claude/skills/collision-proxy
```

## README

# Collision Proxy

Simple, stable colliders. Prefer primitives and convex pieces over render mesh.

## When to Use

- Game physics / blocking volumes
- Unreal UCX export
- Unity mesh or primitive colliders
- Hitboxes for interactables

## Workflow

```
Identify collision needs → Build proxies → Name correctly
  → Test overlaps → Export with render mesh
```

## Collider Types

| Type | Use |
|------|-----|
| Box | Crates, walls, simple props |
| Capsule | Characters, poles |
| Sphere | Balls, soft approximates |
| Convex hull | Organic / irregular single body |
| Multiple convex (UCX) | Vehicles, complex props |

## Unreal Naming

```
UCX_SM_Asset_01
UCX_SM_Asset_02
```

- Must match associated mesh naming rules for auto-association
- Convex only for UCX

## Unity Notes

- Prefer engine primitives when possible
- Mesh colliders: convex toggle for dynamic rigidbodies
- Keep proxy collection exportable

## Authoring Rules

1. Slightly smaller than visual mesh to reduce snagging (project-dependent)
2. No holes; watertight convex pieces
3. Apply scale
4. Origin aligned with render mesh
5. Collection: `COL_Collision_[Asset]`

## Validation

- [ ] Player cannot fall through intended blockers
- [ ] No huge invisible walls beyond mesh
- [ ] Wheel/character capsules oriented correctly
- [ ] Named for target engine

## Constraints

### MUST DO
- Prefer few simple shapes over one complex mesh
- Match engine naming conventions
- Keep proxies in dedicated collection

### MUST NOT DO
- Use render LOD0 as physics mesh by default
- Non-convex UCX for Unreal auto-convex workflows

## Reference Guide

| Topic | Reference | Load When |
|-------|-----------|----------|
| Collider Recipes | `references/collider-recipes.md` | When needed |
| Engine Naming | `references/engine-naming.md` | When needed |