fertilesoilproductions/mast

MAST, short for Modular Asset Staging Tool, is a free extension for the Unity game engine made by Fertile Soil Productions. It gives level designers and game creators a set of tools inside the Unity editor for building scenes out of modular pieces, like walls, terrain chunks, or props that snap together. The core idea is a grid based placement system. You can draw single pieces, draw continuous rows of them, or fill an area, and the grid can be moved, rotated, or scaled to follow any object you attach it to. Placed pieces claim the exact grid cells their shape fills, so parts will not overlap by accident unless you hold a key to force it. A tool called the greeble tool lets you scatter small surface details, like bolts or vents, evenly across the face of any placed model. There is also a material painter with a full undo history, a randomizer that can vary the rotation, scale, position, or even swap which prefab gets placed, and hotkeys that can be rebound to any key combination. Once a scene is built, MAST includes finishing tools: a wizard that turns folders of models into ready to use pieces, a way to merge meshes by material, a tool to swap materials across many objects at once, and an assembly creator that bundles placed pieces into a single reusable prefab. MAST requires Unity 6.0 or newer and works with both the Universal Render Pipeline and the older Built in Render Pipeline, with no extra outside dependencies needed. The repository also ships a small free asset pack called Modular Pixel Forest so newcomers have something to place right away, plus a full written manual. The tool itself is released under the MIT license, meaning it can be used and modified freely, though the included sample models remain owned by Fertile Soil Productions. The project is aimed at giving new creators, especially those without a big budget, a practical way to block out and dress up 3D scenes quickly.