Relief map generator, a 3D heightmap of Bulgaria you can hold and print
On a flat classroom map, relief is a scatter of faint contour lines a pupil cannot really feel. Pick a region of Bulgaria, or your own coordinates, and the tool builds a coloured heightmap on screen and an STL file you can print, with the vertical exaggeration needed to make Mount Musala actually stand up on the model, and honestly labelled as exaggeration, not disguised as scale.
Open the relief map generator A free account opens this tool. The interface is in English and nothing you enter leaves your browser.How it works
Three steps to a printable relief map, plus twelve further modes for deeper geography lessons.
Choose a region, a scale and a vertical exaggeration
Pick one of six preset regions of Bulgaria, from the whole country to a single mountain range or the Danube plain, draw your own coordinates, or upload a real elevation grid as CSV or a PGM heightmap. Set the map scale as 1 to N and the vertical exaggeration, and the tool warns if the model would come out larger than a typical FDM print bed.
Read the hypsometric map and the cross section
The relief is coloured by height on the same scale used in school atlases, from green lowlands to brown peaks. Click two points on the map to draw a cross section between them, or use the west to east, north to south or diagonal presets, and see exactly how the terrain rises and falls along that line.
Check the print limits, then switch modes if you want more
The tool checks the mesh resolution against the minimum printable wall and base thickness, and gives volume and weight at full density and at a chosen infill. From there you can switch to any of the eleven other modes, slope and aspect, hillshade, watershed, flood level, viewshed, sunlight hours, erosion, avalanche risk, fractal generation or print tiling, all on the same terrain grid.
Twelve modes on the same terrain grid
Every mode reuses the same interpolated heightmap, so the numbers stay consistent from one tab to the next.
Built to show the scale problem honestly, not hide it
Bulgaria is wide enough and its highest point close enough to sea level that the real relief is invisible at print scale unless you exaggerate it, and the tool says so out loud.
Vertical exaggeration stated, not hidden
Bulgaria's height range compressed to an A4 sheet at true scale would be under two millimetres, too small to see or feel. The tool multiplies the vertical axis only, never the horizontal ones, and warns above a 10x exaggeration that the visible slopes are not the real slopes, and again above 25x that the map has become a caricature.
Print limits checked against real thresholds
The finest mesh detail the relief can resolve is checked against the minimum reliable FDM wall, and the base thickness that carries the whole model off the bed is checked too, both drawn from EduFacturing's DFAM rules core rather than picked at random.
Twelve modes, one consistent terrain grid
Slope and aspect, hillshade, ruggedness, watershed, flood extent, viewshed, sunlight hours, erosion and avalanche risk all read from the same interpolated elevation grid as the printable relief map, so a lesson can move between modes without the numbers disagreeing with each other.
What each mode is and is not
Hillshade is a local lighting model, not a ray traced shadow from a distant ridge. The watershed mode uses a simplified flow model, not the original published algorithm exactly. Fractal terrain replaces the real geography while it is active. Each mode says plainly what it approximates and what it leaves out.
Frequently asked questions
Why does the relief need vertical exaggeration at all?
Bulgaria is roughly 511 kilometres wide and its highest point, Musala at 2925 metres, sits only a little above sea level in relative terms once the whole country is scaled down. Fitting the country onto an A4 sheet needs a scale of roughly 1 to 1,720,000, which would shrink that entire height difference to under two millimetres, invisible and unprintable. Exaggerating only the vertical axis is what makes the shape of the terrain visible at all.
How does the tool know the elevation at a point I have not marked?
About thirty named control points with known coordinates and heights cover the main relief forms of Bulgaria, and elevation elsewhere is estimated by inverse distance weighting, where nearby points count more than far ones. This gives a smooth approximation good enough to show the shape of the terrain for teaching, but it is not survey accuracy. For a specific area, you can upload real SRTM or ETOPO1 data as a CSV grid or a PGM heightmap instead.
What is the difference between hillshade and the sunlight hours mode?
Hillshade is a purely local lighting calculation from the slope of each cell facing a fixed sun direction, and it does not know that a ridge behind a cell might be casting a shadow onto it. The sunlight hours mode runs an actual horizon test along the sun's path for each point in the day, so a valley genuinely shaded by a ridge in front of it comes out darker, hour by hour.
Can I generate terrain if I do not want to use real Bulgarian geography?
Yes. A fractal generator builds plausible mountains from a seeded Diamond-Square algorithm, and a tectonic generator builds ridge lines from simplified fault formation. Both use a fixed seed, so the same seed always returns the same terrain, but while either is active it replaces the selected region with invented, not real, geography.
What happens if the model is bigger than my print bed?
The tiling mode splits the model into a grid of plates, each within your print bed size, with simple rectangular tabs at every internal seam to key the pieces together when glued. The combined volume of the tiles, minus the material shared at the seams, is checked to match the volume of the whole model, so nothing is silently added or lost by splitting it.
Is the flood or watershed mode accurate enough for real hydrology work?
No, and the tool says so. The flood fill finds a genuinely connected flooded area rather than just every cell below a level, and the watershed flow accumulation preserves the total volume of rainfall as a check, but both run on the same approximate, interpolated elevation grid as the relief map itself, which is built for teaching the shape of drainage and flooding, not for engineering grade hydrology.
Other tools
Part of the EduFacturing tool set for geography, engineering and 3D printing education.
The rest of the tool set
A free account opens the full set: relief maps, timelines, cutting data, printability checks and the rest.
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