Real-world object sizes for accurate 3D modeling. Toggle between metric and imperial units. Reference humans, doors, vehicles, furniture, and architectural elements.
Real-world scale ensures: physics simulations work correctly (gravity, collisions, cloth). Lighting calculations produce accurate falloff and shadows. Textures map at the right density. Interoperability between software a meter in Blender should be a meter in Unreal. Incorrect scale is the #1 cause of import/export problems in 3D pipelines.
Blender: 1 unit = 1 meter (default). Maya: 1 unit = 1 cm. 3ds Max: 1 unit = 1 inch. Unreal Engine: cm (1 unit = 1 cm). Unity: meters (1 unit = 1 m). Houdini: 1 unit = 1 meter. Always verify your scene unit settings before starting work it's much harder to fix scale after modeling.
In Blender: select object, press N for the side panel, adjust Dimensions directly (not Scale). Apply scale with Ctrl+A > Scale. In Maya: Modify > Freeze Transformations. In 3ds Max: Utilities > Reset XForm. Always apply scale before exporting unapplied scale causes shading artifacts and broken physics.