Blockout
Rough mass + scale placeholder
Also known as: Greybox · Whitebox · Block-in · Greyboxing
Definition
A blockout is the rough, untextured first pass of a 3D scene or asset built from primitive shapes — boxes, cylinders, simple meshes — sized to establish scale, composition, and gameplay flow before detailed art begins. Studios block out levels for weeks of playtesting before any final mesh is built. The blockout phase is where mistakes are cheap; in textured-detail phase they're catastrophic.
In production
Blockout in Unreal Engine 5 using BSP/Geometry brushes or simple modular blocks, sized against a placeholder character capsule (typically 180cm tall, 34cm radius) so scale reads correctly before any art pass begins. Lock proportions and gameplay readability before exporting to a DCC like Maya or Blender for final modeling — reversing that order means re-blocking after expensive asset work is already sunk. Greybox shaders (matte grey, flat lighting, no textures) prevent the team from prematurely judging "look" during structure review, keeping playtests focused on navigation, sightlines, and combat spacing rather than material choices. A common failure mode is skipping blockout playtests entirely and discovering a corridor is too narrow for combat only after it's fully textured. Tools like ProBuilder in Unity serve the same purpose — fast, disposable geometry that gets fully deleted and rebuilt once the layout is approved.