# Materials: Commands {#mat_commands}
## tcgen
### Syntax

**tcGen <coordinate source>**

### Overview

Specifies how texture coordinates are generated and where they come
from. Valid functions are **base**, **lightmap** and **environment**.

### Sources {#sources}

#### base {#base}

Base texture coordinates from the original art.

#### lightmap {#lightmap}

Lightmap texture coordinates.

#### environment {#environment}

Make this object environment mapped.