Multi-colour printing: opening your 3MF in Bambu Studio, OrcaSlicer and PrusaSlicer

This page picks up where Multi-colour printing with 3MF leaves off: you have a painted model and a printer that holds several filaments (an AMS, an MMU, a tool changer). Here’s what Shapeaway puts in the 3MF, and how to get it onto the right filaments in your slicer.

What Shapeaway puts in the file

Your paint, reduced to N filaments

In the Print tab, go to the Export step, choose 3MF · multi-colour, and set Filaments to the number your printer can load (1 to 16; four by default, since an AMS holds four). Shapeaway then:

1. Looks at the colour of every triangle, weighted by its area, so big painted areas count for more than small ones.
2. Groups colours that look alike (it compares them the way your eye does, not by RGB numbers) into at most N groups.
3. Gives each group the colour of its biggest area of one shade, not an average. A black eye with blended edges stays black instead of turning grey.
4. Puts every triangle on its group’s filament.

If your paint already has N colours or fewer, they’re kept exactly. The same model and filament count always give the same result.

The filaments are named Filament 1, Filament 2 and so on, each with its colour attached, so the slicer can show them.

Parts and bases as separate objects

Every visible object goes into the 3MF as its own object, named as it is in Shapeaway: the parts from Split into parts, a base, a separate sword or necklace. They:

• keep their places relative to each other, with the lowest point resting on the plate and the whole group centred on it;
• share one palette, so Filament 2 is the same colour on the figure and on its base.

Hair is included as printable strands when hair export is on.

Each object as its own file

If you export with Each object, every object gets its own 3MF and its own palette. Filament 1 in one file may be a different colour from Filament 1 in the next. For a multi-colour print, export Everything (or Selected) to one 3MF instead.

Limits

• Similar shades share a filament. Two reds, or a yellow and a green, end up on one filament when there aren’t enough to go round. Paint in clearly different colours if you want them kept apart.
• With N filaments, the biggest areas keep their own colour. A small accent (an eye, a gem, a belt buckle) can be folded into a nearby colour when it’s outnumbered. Raise the filament count, or make the accent a separate object.
• Gradients become steps. Soft blends turn into bands of the nearest filaments.
• Detail is limited by the triangles. Each triangle gets one filament, and the slicer has the final say on how fine a line it can print.

Bambu Studio

Bambu Studio 2.5 and later show a Standard 3MF Import color dialog when you open a 3MF made by another app such as Shapeaway.

1. Drag the 3MF onto the plate (or File › Import › Import 3MF/STL/STEP/SVG/OBJ/AMF…).
2. In Standard 3MF Import color, check each colour from the file against the filament it’s assigned to. Change any that land on the wrong AMS slot.
3. Confirm. Bambu Studio paints the colours onto the model, the same as if you’d used its own colour-painting tool.
4. Check the Preview after slicing, and touch up with the colour-painting tool if needed.

Good to know:

• Because the colours arrive as painting, changing an object’s filament in the object list doesn’t recolour painted faces. Use the painting tool, or the filament mapping, instead.
• If you cancel the colour dialog, the model comes in as plain shapes. You can then give each object its own filament in the object list, which works well for a figure and base in two colours.

OrcaSlicer

OrcaSlicer is built on Bambu Studio’s code, but its handling of 3MF files from other apps differs between versions. In OrcaSlicer 2.4, a 3MF from another app opens as shapes only, without asking. We haven’t confirmed whether the paint comes across.

If the colours come in, check them against your filaments as for Bambu Studio. If they don’t:

1. Import the 3MF (drag it onto the plate, or File › Import). Avoid Open Project, which can replace your printer and filament settings.
2. In the object list, give each object its own filament: the figure one colour, the base another, a separate weapon a third.
3. For colours within one object, use the colour painting tool to paint them on, using the Shapeaway render as your guide.

PrusaSlicer

As far as we can tell, PrusaSlicer doesn’t read the colours in a 3MF made by another app: it opens the shapes and hands out extruders in turn, one per object. So the separate objects come through, but painted areas within an object don’t.

1. Open the 3MF. Answer Yes if PrusaSlicer asks whether to load several objects as one object with several parts and you want them to stay together.
2. In the object list, set each object’s (or part’s) extruder to the filament you want.
3. For colours within one object, use Multimaterial painting to paint them.

Plan for it in Shapeaway

For a print you’ll slice in PrusaSlicer or OrcaSlicer, keep each colour you care about as a separate object in Shapeaway: a base, a cloak, a weapon. Objects always arrive separately, and giving each one a filament takes seconds.

Related

• Multi-colour printing with 3MF
• Exporting to your slicer
• Painting