# LOD — what levels of detail are and when you need them

> LOD means several versions of one model with different detail: the full one for close-ups, a simplified one for mid-range and almost a silhouette for far away. The engine switches between them by distance to the camera, so a scene with hundreds of objects stays fast. LOD is needed in games and large interactive scenes; for a single product in a website viewer, one well-optimized model is usually enough.

Source: https://gluke.ru/knowledge/lod · Author: Alexander Glukhov · Updated: 2026-10-08

A car at the far end of a street takes up a few dozen pixels on screen — drawing it with every headlight and grille is pointless. LOD lets each object be drawn with exactly as much detail as is visible.

## The levels

> **Illustration:** One car in three versions: LOD0 with a dense mesh, windows and wheel rims; LOD1 with a sparser mesh and simpler wheels; LOD2 almost a silhouette with no windows.
>
> The mesh thins out, while the silhouette and color stay the same.

- **LOD0**: the full model for close-ups.
- **LOD1**: simplified — small details removed, a sparser mesh.
- **LOD2**: almost a silhouette for far away.

The number of levels and how much they're simplified depend on the project.

## How they switch

> **Illustration:** A camera on the left and three distance zones: near — LOD0, a large car; mid — LOD1, a smaller car; far — LOD2, a very small car.
>
> The farther the object, the smaller it is on screen and the simpler the version.

The engine checks how far the object is from the camera, or how much of the screen it covers, and picks a level. The switch should go unnoticed, so only what can't be seen at that distance anyway is simplified.

## When you need it and when you don't

> **Illustration:** Four situations: a game with cars on a street — LOD; a big scene such as a village or a plant — LOD; one product in a viewer — one model; AR of a single object — one model.
>
> LOD is needed when there are many objects at different distances.

- **Games and simulators**: many objects at different distances.
- **Large interactive scenes**: a village, a plant, a residential complex.
- **One product in a [viewer](https://gluke.ru/knowledge/glossary#viewer)**: the camera is always close, so one optimized model is enough. How to make it lighter is covered in [Why a 3D model lags on a phone](https://gluke.ru/knowledge/mobile-3d-performance).
- **AR of a single object**: one model as well.

## What to put in the brief

- **The budget**: how many triangles and materials each level may have. The developer or the project's engine sets it.
- **How many levels** and at what distances they switch.
- **What stays the same on every level**: the silhouette, the color, recognizable details.

## What it looks like in practice

[RP Grand](https://gluke.ru/projects/rp-grand): car assets for a mobile game — LOD0, the full build for close-ups, around nine thousand triangles; LOD1 for mid-range; LOD2, a silhouette for distant streets. In the case study's interactive garage you can switch the levels and look at the mesh.

## Common mistakes

- Making LODs for a single model in a viewer.
- Simplifying so much that the silhouette changes: the switch becomes visible.
- Different materials on different levels: the object "flickers" in color when it switches.

## Checklist

1. Is LOD needed: are there many objects at different distances?
2. A triangle and material budget for each level.
3. Switching distances.
4. The same silhouette and color on every level.