Print in several colors¶
The multi-color 3MF holds up to five parts of one object on up to four filaments, so it fits an AMS lite:
| Filament | Part | Display color |
|---|---|---|
| 1 | land |
green |
| 2 | water |
blue |
| 3 | buildings |
white |
| 4 | roads |
dark gray |
| 1 | border |
green |
The border prints in the land filament, and bridges are in the roads part. Parts without geometry are left out, and the filaments after them move
up one: there is no buildings part without buildings, no roads part
without roads or bridges, and no border part without a frame.
Make one¶
In the web app, check Multi-color 3MF, check Add roads if you want the roads part, and set a Border frame width if you want the border part. Pick your printer's plate under 3MF plate. Generate, then click Download multi-color 3MF.
From the command line:
satprint build --bbox 45.43 12.32 45.446 12.343 --buildings --frame 5 \
--3mf venice.3mf -o venice.stl
Add --plate 180 for an A1 mini.
Print it on a Bambu printer¶
- In Bambu Studio, set up one filament per color, up to four, in the left sidebar, or sync them from the AMS.
- Open the 3MF. Bambu Studio reports that it loads "geometry only", as it does for any 3MF it did not write. The part names and filaments still come through. The model lands centered on the plate you chose: 256 mm (A1, P1, X1) or 180 mm (A1 mini).
- To check or change a part's filament, open the object list: in the left sidebar, under Process, click Objects and expand the model.
- Slice. The preview shows each part in its filament's color, and a prime tower for the filament changes.
To keep your filament choices and print settings, save the result with File > Save Project As. That project opens without the "geometry only" message.
Other slicers open the same parts with every part on filament 1. Assign the filaments by hand.
If slicing fails or warns¶
"A G-code path goes beyond plate boundaries." The prime tower is off the plate. A multi-color print builds this small block beside the model: at each filament change the printer primes the new filament on it, so the model gets clean color. The tower holds the same amount of filament on every layer, so the thinner the layers, the larger it gets, and on a 0.2 mm nozzle preset Bambu Studio's default spot can put it past the plate edge. In Prepare, drag the tower into open plate space away from the edges and slice again. If it does not fit anywhere, raise Prime tower width or lower Prime volume and the tower brim under Process > Others.
"Floating cantilever." Bambu Studio found overhangs with nothing under them, usually bridge decks between piers. Short spans print fine without supports. To shorten long ones, build again with a smaller Bridge piers spacing, or turn on tree supports.
Print time. Each filament change takes about a minute on an A1, and a print has up to three per layer near the water line. Most of a long estimate is still the printing itself: a 0.2 mm nozzle at 0.06 mm layers can take a day on a 120 mm city. The 0.10 mm preset on the same nozzle takes far less and still shows the buildings well.
How the parts are made¶
- Water is the sea, river and lake shapes from the OpenStreetMap
waterlayer, plus the flattened sea. Swimming pools are left out, since many are on roofs. - Land and water are the terrain block split along that water map, one grid cell at a time. The water is a skin 0.6 mm thick, and the land filament fills the base under it, so the lower layers print in one color with no filament changes for water. The two solids meet exactly and fill the same block together. A river narrower than one grid cell does not show, so raise the resolution to keep it.
- Buildings are the same solids as in the STL, sunk 0.3 mm into the terrain. Slicers resolve that overlap.
- Roads are the same raised strips as in the STL, sunk 0.3 mm into the terrain like the buildings. Bridges are in this part too, so a bridge prints in the road gray.
- Border is a closed rectangular ring against the walls of the block, 1 mm above the base by default.