---
title: "Projection | Gl style specification"
description: "Configure map projections using various types and interpolation expressions."
---

> For AI agents: a documentation index is available at [/llms.txt](https://docs.maptiler.com/llms.txt). Markdown versions of all pages are available by appending .md to any URL.

# Projection

The projection configuration

```json
projection: {
  "type": [
    "interpolate",
    ["linear"],
    ["zoom"],
    10,
    "vertical-perspective",
    12,
    "mercator"
  ]
}
```

## type

Optional [ProjectionDefinition](../types/#ProjectionDefinition). Defaults to `mercator`. Supports [interpolate](../expressions/#interpolate) expressions.

The projection definition type. Can be specified as a string, a transition state, or an expression.