Tools
Physics Placement Assist
An in-progress Unreal Engine 5.6 editor plugin that turns manual prop placement into an undoable physics-assisted workflow using the editor world's Chaos scene.
Placing a pile of props by hand is slow in exactly the wrong way. Every object has to be nudged out of an overlap, rotated until it looks natural, and checked again from another angle. Physics Placement Assist keeps the normal Unreal Editor selection and transform workflow, but lets Chaos do that last part.
The editor workflow
With assist mode enabled, actors dragged with the standard gizmo collide with the level instead of passing through it. Releasing the gizmo hands the selection to a settle simulation so gravity, contact and friction can finish the placement. A separate command drops the current selection on demand, and arrange commands can level a group, randomize its yaw, clump it or spread it before the same settle pass.
The result remains editor work. The plugin adds no runtime components and ships nothing in a packaged game. Commands live in the Tools menu, can be rebound in Editor Preferences, and expose per-user tuning for simulation time, fixed timestep, gravity, collision and settle thresholds.
Preserving the scene around the simulation
Before a drop, the plugin saves each actor’s mobility, collision mode, gravity, CCD and transform. It then advances the editor world’s Chaos solver in fixed steps until the bodies remain below the linear and angular velocity thresholds, or until the time budget is exhausted. Temporary flags are restored before the settled transforms are applied inside one editor transaction, so a single undo reverts the complete operation.
Nearby render-only scenery can participate through transient scene proxies that borrow already-cooked triangle meshes without modifying the user’s components or assets. For props that lack usable simple collision, the plugin also exposes bulk convex-hull generation through Unreal’s V-HACD path.
Where it stands
Version 0.1 is an editor-only beta for Unreal Engine 5.6. Static meshes with usable collision are the primary path today; instanced meshes, foliage, spline meshes and skeletal meshes remain outside the supported set. A demonstration/screenshot/video is still to come, but the repository documents the current commands, settings, limitations and roadmap.