Unreal does not use your render mesh for collision — it wants separate, much cheaper shapes, named so its FBX importer recognises them. Collision Maker builds those shapes and names them. Select an asset, press Generate Collision, and it decomposes the mesh into convex pieces, fits boxes, spheres and capsules where they honestly belong, and parents the result to the asset.

No. Collision Maker is pure Blender and never talks to an engine. It produces shapes built to Unreal's conventions; getting them into Unreal is a separate step. Unreal Bridge automates that if you want it, but any exporter that honours the same naming convention will carry them.

3.3 through 5.2, from one package. It installs as a modern extension on 4.2 and newer, and as a classic add-on on 3.3 – 4.1. Every release is tested end to end on 3.3, 3.6, 4.2, 4.3, 4.5, 5.0, 5.1 and 5.2 — including installing the shipped archive on each of them.

Yes. There is nothing platform-specific in it.

3D Viewport sidebar — press N — then the Unreal Tools tab, then Collision Maker. That tab is shared with Unreal Bridge and LOD Maker when they are installed, so everything that feeds Unreal is in one place. Rename it in preferences and the others follow.

It rasterises the asset into a voxel grid and splits that grid into convex pieces, best-first, until every piece is as convex as Accuracy asks for or the piece budget is spent — the same kind of algorithm as V-HACD. The grid only decides where to cut: each piece is then hulled from the original vertices it covers, so the collision surface is your mesh's rather than a stair-stepped version of it. A piece becomes a box, sphere or capsule only when it honestly fills one.

The presets are a ladder, so pick by how much the player interacts with the asset. Blockout Box is one level box. Coarse Prop is background clutter. Simple Prop is the default and suits most props. Detailed Prop follows recesses and curves. Precise Prop gives every major surface its own piece. Follow the Shape goes as close as convex collision gets. Architecture and Foliage / Small sit outside the ladder for kit pieces and scatter.

On a fourteen-part kiosk those six rungs give 1, 4, 8, 15, 28 and 53 shapes, in roughly 0.3 to 12 seconds.

Resolution is voxel cells along the longest side — higher sees smaller features and costs more time. Max Pieces caps how many shapes a decomposition may produce. Accuracy is how closely the pieces must follow the surface before splitting stops. Prefer Boxes lets a piece ship as a box, sphere or capsule when one fits, with Box Fit setting how full it has to be. Each Object Separately gives every mesh object of the asset its own grid and budget. Hull Verts is the vertex budget per hull, and Padding grows primitives slightly so a character never clips the visible surface.

It belonged to the old engine and has no equivalent on the voxel one, so it was removed in 1.1.0. Accuracy is the knob that replaces it. A preset file saved by version 1.0 still loads; the old value is dropped and the preset lands on the default accuracy.

Yes. A voxel grid has a volume whatever the topology, so open shells, thin panels and overlapping parts all decompose normally. Ten of the fourteen parts of the kiosk this engine was built against are open meshes.

Only if you asked for it. Box alignment defaults to Upright: level with the floor, free to rotate about Z only, and only when the yaw genuinely buys volume. Oriented is the setting that produces tilted boxes — the panel warns you when it is selected. If you are seeing tilt you did not want, switch back to Upright.

Because Box Fit is set low enough that each segment counts as boxy. Raise it and curved or tilted pieces stay as hulls that follow the surface; that is exactly what the higher rungs of the ladder do. Turning Prefer Boxes off entirely ships every piece as a hull.

Yes — that is what Mark Selected as Collision is for. Select your shapes along with the asset and it renames them to the convention, parents them, and tags them exactly like generated ones. From then on they are indistinguishable: the registry lists them, the SHAPES list counts them, Preview shows them, Remove clears them.

Yes. Edit Collision opens a session on one asset where Add Shape drops a box, sphere, capsule or convex hull that you move and scale with the normal tools, while the asset itself stays locked so you cannot nudge it by accident. Confirm keeps the result and Cancel restores exactly what was there.

Yes. Every row in the SHAPES list has a pencil that opens that shape alone in Edit Mode, framed and ready to reshape with the normal tools. Tab back when you are done. Editing a box warns you that it has to stay a box to import as one.

Select more than one and a BATCH section appears: Generate Collision for All N and Remove Collision from All N. An asset with nothing to remove is skipped rather than counted as a failure, so a mixed selection still succeeds, and the whole batch is one undo step.

By name. Unreal's FBX importer recognises UBX_ (box), USP_ (sphere), UCP_ (capsule) and UCX_ (convex hull), each followed by the asset root's name. Collision Maker names every shape that way, which is the entire integration — nothing to configure.

No. Any exporter that honours the naming convention will carry the shapes. Unreal Bridge simply removes the manual steps: the shapes ride inside the asset's FBX with their materials stripped, and Auto Generate Collision is left off so yours are the shapes Unreal uses rather than something it invented.

Not if Auto Generate Collision is off in your import settings. Unreal Bridge leaves it off deliberately. If you export by hand, turn it off yourself, or Unreal may add a generated hull alongside yours.

Unreal is happiest with a couple of dozen convex elements per asset, which is why Max Pieces exists and why the default preset stops at eight. The SHAPES list shows a running triangle total at the bottom so you can see the cost before it reaches the engine rather than after.

They are shown the moment they are built — turn that off with Preview After Generate in preferences if you would rather ask for it. After that, the SHAPES section lists them grouped into a dropdown per Unreal prefix, each with its own count and triangle total; click a row to select and frame that shape. Preview Collision makes the active asset see-through with its shapes on top, and puts your shading back when toggled off. For the whole scene, COLLISION REGISTRY lists every asset that has collision, with search, filters and Jump to Asset.

The VISIBILITY section, which appears whenever the file holds any collision: Show and Hide Selected act on every selected asset at once, and Show and Hide All on every shape in the file, orphans included.

Because triangles are what Unreal receives. The shapes are authored as quads and ngons and triangulate on export, so a face count understates the real cost by about half — a box reads 6 faces and arrives as 12 triangles. Every row, every group header and the total at the bottom are in triangles.

No. The shapes are new objects parented to your asset. Your mesh is untouched.

No. It opens no sockets, sends no telemetry and checks no licence. The Documentation and Discord buttons hand a URL to your default browser; the add-on makes no request and sees no response.

GPL-3.0-or-later. The full text ships in the add-on as LICENSE.