Joint Snapping System Documentation

This guide covers the modern Joint Snapping System workflow: scene-native Joint authoring, Universal Joints, Joint Groups, Prefabs, Lists, Packs, Presets, Precision Snapping, tagged procedural tools, compound thumbnails, and Unreal-focused engine export.

Blender → Joints → Prefabs → Packs → Engine

Install and open JSS

1. In Blender, open Edit → Preferences → Add-ons → Install…
2. Choose the Joint Snapping System .zip file.
3. Enable Joint Snapping System.
4. In a 3D Viewport, press N and open the Joint Snap tab.

The bundled Starter Pack is initialized automatically on first run. Modern startup only prepares missing content and previews.

How the system is organized

Create Joints directly on scene objects

Select a mesh and press Shift+J to open Joint Tools.

• Add Universal Joint From Selection — create a Joint from selected faces, edges, or vertices.
• Batch Jointify From Selection — create multiple Joints from selected geometry.
• Magical Jointify — automatically create useful Joints from mesh surfaces.
• Generate Joint Cage — build a configurable Legacy-style X/Y/Z Joint layout around a scene mesh.
• Stamp Snapping Points — transfer an authored Joint layout to another scene object while preserving compatible metadata.

Orientation-aware modular connections

Universal Joints can store position and orientation. Surface follows the authored surface, Orthogonal uses position-only behavior, and manually rotated Joints become Custom. Use Flip Joint Direction when a Joint faces the wrong way.

Edit legacy and Universal Joints together

Multiple Blender objects, one logical asset

Select the objects that belong together, make the intended Primary active, then use Shift+J → Create Joint Group.

• Primary — the structural owner and main selectable object.
• VISUAL — additional visible geometry that travels with the asset.
• COLLISION — semantic collision geometry; displayed as wire for clarity.
• LOD — alternate level-of-detail geometry with an assigned LOD level.
• Modifier dependencies stay dependencies and are not incorrectly treated as visible Joint Group members.

Save and update directly from the scene

Use Save Prefab to store the selected Joint-Ready object or Joint Group in the active Pack/List. Spawned Prefabs retain stable source identity, so they can be renamed and edited in Blender and later written back with Update Prefab.

Spawned Prefabs use independent editable mesh datablocks, so editing one placed instance does not modify other existing or future copies.

Keep the Blender asset intact

Modern Prefabs preserve supported modifier relationships, dependency objects, material assignments, image textures, shading information and Joint metadata throughout the Prefab → List → Pack → shipping lifecycle.

Snap, rotate, reposition and refine

Choose the exact two Joints that connect

Hold Shift during placement to select a precise target Joint and source Joint. JSS aligns their positions and orientation frames. Press Q for Position Only behavior, or use Shift+R for incremental rotation while preserving the connection.

Socket / Attachment rules for procedural building

Assign Tags to Legacy or Universal Joints and classify them as Socket or Attachment. Populate Tagged Joints can then choose compatible Prefabs using seeded variation, density, orientation rules and cascade depth. Randomize Selected can reroll individual generated branches.

Convert a Blender-authored multi-object build into a modern Joint Group

Process Assembly is now a scene-authoring helper, not the retired saved-Assembly asset workflow. It analyzes selected geometry, prepares connection information, and hands the result into Joint Group creation so the build can continue through the modern Prefab pipeline.

Automatic compound asset previews

Prefab thumbnails are generated and cached automatically. Joint Group thumbnails render the Primary + VISUAL members while excluding COLLISION, LOD, helper geometry and hidden dependencies. Textured Prefabs use their authored materials and textures in thumbnail rendering.

Build reusable content libraries

• Open a Pack from the N-panel to access that Pack's Prefabs, Lists and Presets.
• Use Pack-owned Prefabs as a staging area before organizing assets into named Lists.
• Use Export Pack and Import Pack for portable content sharing.
• Use Share A List / Import List for narrower content exchange.

From Blender-authored assets to Unreal-ready files

ASSET export

A logical Joint Group becomes one visible static mesh built from the Primary and VISUAL members. COLLISION members export separately with Unreal-compatible UCX naming.

LEVEL_CHUNK export

Selected logical roots can be combined into a larger visible chunk mesh for Blender-authored environment sections. Use JSS for modular authoring and chunk preparation; use Unreal for the final world/runtime layer.

Collision, LODs and validation

• COLLISION members export as deterministic UCX collision meshes.
• LOD members can export as separate _LOD1, _LOD2... FBX files.
• Portable textures are copied into the export package where supported.
• Preflight reports PASS / WARNING / ERROR states before files are written.

Mesh cleanup with shading preservation

Make Solid includes Join / Boolean-based cleanup workflows, interior-face removal, Fix N-Gons, and shading options. Original Shading preserves authored shading where possible, while Blender-version-specific Auto Smooth / Smooth by Angle behavior is handled compatibly.

Common checks

Blender 3.3 → 5.2 LTS

Joint Snapping System is designed for Blender 3.3+ and includes compatibility handling for Blender 3.x, 4.x and 5.x API differences, including shading, normals, previews, scene behavior and asset persistence.

Joint: authored snapping connection point · Universal Joint: orientation-aware Joint · Joint Group: Primary + semantic Secondary objects treated as one logical asset · Prefab: saved reusable authored asset · List: ordered Prefab collection · Pack: portable content library · Preset: reusable List configuration.

Build modular. Stay in Blender.

If you hit an edge case, include your Blender version, the JSS version, the workflow you were using, and a short screen recording or reproducible scene when possible.