DIGITAL ELEVATION MODEL

DEM Software for Large Digital Elevation Models

STREAM is high-performance DEM software for viewing and analyzing large digital elevation models. It streams gigabyte-scale digital elevation models straight from GeoTIFF, so you can pan, zoom and measure across a whole survey without waiting for the file to load — and turn the elevation surface into real engineering results.

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What is a DEM (Digital Elevation Model)?

A Digital Elevation Model (DEM) is a raster grid where each cell stores a ground elevation. It is the base layer for almost every terrain workflow — volumes, cross-sections, slope, hydrology and contours are all derived from it.

A DEM (bare-earth) is often distinguished from a DSM (Digital Surface Model, which includes buildings and vegetation) and a DTM (Digital Terrain Model). STREAM opens all of them and computes on the elevation surface directly.

DEM / DSM / DTM — Three different surfaces of the same terrain — which one to use, at a glance. — DEM / DSM / DTM
Three different surfaces of the same terrain — which one to use, at a glance.
**DSM — top surface** — includes buildings, trees and structures
**DTM / DEM — bare earth** — real ground with objects removed
**Objects** — present in the DSM, absent in the DTM
**Difference = object height** — building/tree height comes from this gap

DEM Software in STREAM

Stream gigabyte DEMs

Out-of-core streaming loads only the area you are looking at in full detail, so hundreds of MB — even GB — of DEM open without lag.

GPU terrain rendering

A Vulkan compute raycaster renders the elevation surface in 2D and 3D at full resolution, with shaded relief and color ramps.

Measure & compute on the DEM

Distance, area, elevation, cut/fill volume, cross-sections and stockpiles are all measured directly from the DEM surface.

Analyze the terrain

Run slope, aspect, viewshed, hydrology, contour and sun & shadow analysis on the DEM and save the results as raster or vector.

How to open and work with a large DEM

1
Load the file
Pick the GeoTIFF (or ASC) from the load dialog. STREAM reads the format, detects that it is an elevation raster and shows the progress as a task card.
2
Confirm the coordinate system
Check the CRS STREAM read from the file before the layer is added to the project, so every later measurement lands in the right place.
3
Let the cache build
On first load the DEM is converted to a fast native cache. That is why the same project reopens in seconds afterwards.
4
Navigate
Use fit-to-data to frame everything, switch between 2D and 3D, and read X/Y/Z under the cursor as you move.
5
Measure or analyse
Draw a point, line or area on the surface and apply a measurement, a volume calculation or an analysis to that geometry.

Supported formats

GeoTIFF

Georeferenced elevation raster (primary DEM format)

ASC / DEM

ESRI ASCII grid and common DEM grids

LAS / LAZ

Point clouds rasterized to a DEM on import

Frequently asked questions

What DEM file formats does STREAM support?

STREAM opens GeoTIFF elevation rasters, ESRI ASCII grids (.asc) and common DEM grids, and can rasterize LAS/LAZ point clouds into a DEM on import.

How large a DEM can STREAM open?

STREAM is built for gigabyte-scale DEMs. It streams data out-of-core and converts it to a fast internal format on first load, so large models stay responsive and reopen in seconds.