# DTM

A raster DTM stores height values in a regular grid. The DTM can be exported to the Esri ASCII grid format `.asc`, that can be then imported into **Terrain Builder**. **Terrain Builder** assumes reference coordinates in **UTM** projection.

The add-on only supports grids with equal resolution in both X and Y directions. Each vertex of a DTM mesh represents a pixel of the exported raster.

## Location

The panel is visible for all mesh objects in the Object Data Properties of the Properties editor.

## Properties

<figure><img src="https://418903991-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FNJv4RINtC1OtMV3u9E73%2Fuploads%2F0aq6JTf7JkEHdhZArgGZ%2Fproperties_dtm_panel.png?alt=media&#x26;token=20fa19c8-6b6f-4abb-9bd2-6cc136219ab8" alt="Raster DTM properties"><figcaption></figcaption></figure>

### Cell Size

* Manual: side length of a raster cell is set explicitly
* Calculated: spacing is calculated as the distance between the first two points of the first row, or first column in the raster

### Data Type

* Raster: data points are cell centered
* Grid: data points are on cell corners

### Easting

X coordinate of the reference origin.

### Northing

Y coordinate of the reference origin.

### NULL Indicator

Placeholder value for cells where data does not actually exist.

{% hint style="info" %}
The Null indicator value is technically not used, since the add-on does not support incomplete DTMs, but the parameter is implemented anyway for compatibility purposes.
{% endhint %}