TERRAIN MODELING
STREAM is desktop terrain modeling software for working with elevation surfaces: digital elevation models, surface models and terrain models, plus the point clouds and orthophotos that come with them. It streams gigabyte-scale surfaces straight from GeoTIFF and LAS/LAZ, lets you measure, edit and analyze on them, and exports the results as DXF, CSV, GeoTIFF, KMZ and PDF — on a normal Windows machine, fully offline.
A terrain model is a surface where every position carries an elevation. Almost every engineering answer that involves ground — how much material, how steep, what drains where, what is visible from here — is derived from that surface rather than measured in the field a second time.
So the job of terrain modeling software is narrow and specific: get the surface in without fighting the file size, let you read and measure it honestly, let you change it where the ground has changed, derive the quantities and maps you actually deliver, and hand those results to whatever comes next. STREAM is built around that loop rather than around a general-purpose GIS or CAD model.
Load a GeoTIFF elevation raster — a DEM, a DSM or a DTM — an ESRI ASCII grid, or a LAS/LAZ point cloud that is rasterized to a surface on import. Orthophotos load alongside and drape on the same terrain, and vector data comes in as DXF.
Very large files are streamed out of core: only the area you are looking at is held at full detail, so a survey that would not fit in memory still pans and zooms at full resolution. On first load the surface is converted to a fast native cache, which is why the same project reopens in seconds afterwards.
The coordinate reference system is read from the file and shown for confirmation before the layer joins the project — the one moment where a wrong assumption would silently move every later measurement.
The surface renders in 2D and 3D through a GPU raycaster, with shaded relief and colour ramps so shape is visible rather than inferred. Fit-to-data frames everything, the compass returns you to a top-down view, and X, Y and Z under the cursor update as you move — the fastest sanity check there is that the model is where it should be.
Contours are generated at your chosen interval directly from the surface, and hillshade gives the relief its readable form for a map sheet or a report figure.
Draw points, lines and areas directly on the terrain and apply a measurement to that geometry: distance along a line, height difference, enclosed area, or an elevation profile along the line taken from the surface itself.
Measurements stay as objects in the project with their geometry and their result, so they can be revisited, renamed, recoloured, exported or deleted rather than being a number you wrote down once and lost.
Cut and fill volumes are computed against a reference surface or a reference level, so the same tool answers both 'how much do I remove to reach this grade' and 'how much has changed between these two surfaces'.
Station-based cubature gives cross-section areas and volumes along an alignment, with DXF section drawings for the drawing set. Stockpile volume is computed above a reference base with several modes for the pile toe, converted to tonnage with a material density, and exported as a print-ready PDF report.
Ground changes, and a model that cannot be corrected stops being useful. STREAM can edit the terrain inside an area you draw — raise, lower or level that region — and the edited surface becomes the working terrain that contours, sections, volumes and later analyses all read.
Objects that do not belong on a bare-earth surface, such as a building or a vegetation clump left in a photogrammetry DSM, can be removed from within an area so the surface underneath is what gets measured.
Slope and aspect colour the terrain by gradient and by the direction each cell faces. Hydrology traces flow paths and shows where water accumulates. Viewshed answers what is visible from a chosen point and height. Sun and shadow analysis gives shading and sun hours through the day and the year.
Change detection compares two surveys of the same area and reports deposition and erosion separately, with a volume figure and its uncertainty rather than a single number with no error bar.
Results are overlays on the model and can be exported as raster or vector, so an analysis is a deliverable and not just something you looked at on screen.
Two operations get confused constantly, and confusing them silently ruins a project. Assigning a CRS tells the software how to interpret coordinates that are already there — it changes the label, not the numbers. Transforming reprojects the data into another system — it changes the numbers so the feature stays in the same place on Earth.
STREAM keeps the two apart, reads the CRS from the file where it exists, and lets you assign one where it does not. Mixing layers that disagree is caught at load rather than discovered later, when a measurement is already in a report.
Contours, measured geometry, sections and vector drawings export to DXF for CAD. Tables export to CSV or Excel. Surfaces and analysis rasters export to GeoTIFF with their georeferencing intact. The project can be exported as KMZ for Google Earth, and reports export as print-ready PDF.
The exports carry their coordinate system with them, which is what makes the result usable in the next tool without a manual alignment step.
STREAM is a native Windows x64 application that renders terrain on the GPU through Vulkan. There is no upload step, no per-project quota and no processing queue, so it works with limited or no internet and elevation data never leaves the machine it was loaded on.
Academic use is always free — for researchers and universities, now and in the future.
Each part of the workflow has its own page with the detail, the supported formats and the questions people actually ask.
Streaming very large digital elevation models without waiting for them to load.
Learn moreSurface models that include buildings and vegetation, straight from photogrammetry.
Learn moreBare-earth terrain models and what separates them from a DSM.
Learn moreThe georeferenced raster format that carries both the elevation grid and its CRS.
Learn moreLAS/LAZ from LiDAR or dense matching, rasterized to a surface you can compute on.
Learn moreDraping imagery on the terrain so you can trace features by eye.
Learn moreGPU rendering of the surface in 3D, with shaded relief and colour ramps.
Learn moreRelief shading that makes terrain shape readable on a map sheet.
Learn moreContour generation at your interval, exported as vector for CAD.
Learn moreSlope, aspect, hydrology, viewshed and sun & shadow on the same surface.
Learn moreDistance, height, area and elevation profiles measured on the terrain.
Learn moreCut and fill volumes against a reference surface or level.
Learn moreStation-based cubature with cross-section areas and DXF section drawings.
Learn moreGradient colouring to find steep ground and check design angles.
Learn moreReading, assigning and transforming the CRS of every layer.
Learn moreDXF, CSV, GeoTIFF and KMZ outputs for CAD, spreadsheets and GIS.
Learn moreIt is software for working with elevation surfaces — DEMs, DSMs, DTMs and the point clouds they come from — and deriving engineering results from them: measurements, volumes, contours, slope, hydrology and visibility. It sits between the survey that produced the surface and the drawing or report that has to leave the office.
A DEM is a raster grid of ground elevations. A DSM is a surface model that includes what is standing on the ground — buildings, vegetation, equipment — which is what a photogrammetry pipeline produces first. A DTM is a bare-earth terrain model with those objects removed. STREAM opens all three and computes on the elevation surface directly.
Gigabyte-scale surfaces are the normal case. Data is streamed out of core so only the area in view is held at full detail, which is why a file larger than available memory still pans and zooms at full resolution instead of failing to load.
Yes. You can draw an area and edit the terrain inside it, and you can remove objects that do not belong on a bare-earth surface from within an area. The edited surface becomes the working terrain, so contours, sections, volumes and analyses afterwards all read the corrected ground.
Yes, and it keeps assigning and transforming separate. Assigning a CRS changes how existing coordinates are interpreted; transforming reprojects the data so the feature stays in the same place on Earth. The CRS is read from the file where it exists and confirmed before the layer joins the project.
Yes. Contours, sections, measured geometry and vector drawings export to DXF; tables to CSV or Excel; surfaces and analysis rasters to GeoTIFF with their georeferencing; the project to KMZ for Google Earth; and reports to print-ready PDF.
Yes. Academic use is always free — for researchers and universities, now and in the future. Contact us through the website for an academic licence.
Free beta for Windows x64. Works fully offline with GeoTIFF, LAS/LAZ and DXF.
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