Texel density is texture pixels per unit of world space — commonly expressed as pixels per centimetre or per metre.
Why it matters within a model
If the front of a crate has twice the texel density of its side, the front is twice as sharp. The eye notices this immediately even when it cannot name what is wrong.
Why it matters across a project
Two props next to each other at different densities look like they came from different games. Establishing a project standard early — a single pixels-per-unit figure — is one of the cheapest consistency wins available.
Choosing a value
It follows from how close the player gets and what resolution you can afford. Higher density means more texture memory for the same coverage. A first-person game needs more than a top-down one; a hero asset can exceed the project standard deliberately.
The number matters less than everyone using the same one.
Deliberate exceptions
- Hero assets the player inspects closely.
- Large surfaces — a terrain or a building facade at prop density would need an enormous texture, so these usually go lower and rely on tiling detail materials instead.
- Never-approached background can go lower and free memory for what matters.
Each of these is a decision, not an accident.
Checking it
Apply a checker texture with known square size. Squares should be the same size everywhere across a model, and the same size between models. It takes seconds and catches what eyeballing does not.
Generated models
Reconstruction produces wildly uneven texel density, because the UV layout was a by-product rather than a design. This is one of the strongest reasons to re-unwrap rather than keep the generated layout — the generated texture may look acceptable in isolation and will not sit next to hand-made assets.