Automatic supports (support_auto)
Automatic supports is on or off. Automatic supports grow under every overhang past the threshold angle. Manual supports grow only inside support enforcers and painted areas.
What does each slicer call it?
Five slicers, five spellings of one setting. The scope column is which preset the key belongs to, which is what decides whether changing it follows the printer, the filament, or the print profile.
| Slicer | Key | Scope |
|---|---|---|
| PrusaSlicer | support_material_auto |
process |
| Bambu Studio | support_type |
process |
| OrcaSlicer | support_type |
process |
| Cura | support_enable |
process |
| Creality Print | support_type |
process |
Where does it live in the file?
All five slicers file this under the process preset, so its value follows the print profile rather than the model. A .3mf is a zip, so unzip it and search for support_material_auto, support_type and support_enable, or open the file in preslice and read the Raw tab, which searches every member at once.
Four of the five slicers write their settings into a sidecar part beside the geometry. Cura writes them into the model XML itself, so there is no config part to open.
| Slicer | Part | Format |
|---|---|---|
| PrusaSlicer | Metadata/Slic3r_PE.config |
INI, one key = value per line |
| Bambu Studio | Metadata/project_settings.config |
JSON, one flat object |
| OrcaSlicer | Metadata/project_settings.config |
JSON, one flat object |
| Cura | 3D/3dmodel.model |
XML metadata inside the model part, under a cura namespace |
| Creality Print | Metadata/project_settings.config |
JSON, one flat object |
What values are valid?
Each slicer declares its own type, default, and bounds for its key. They do not always agree, and where they disagree the file is still valid in both: the slicer that wrote it is the one that enforced its own rule.
| Slicer | Type | Unit | Default | Range |
|---|---|---|---|---|
| PrusaSlicer | bool | not declared | 0 |
not declared |
| Bambu Studio | enum | not declared | tree(auto) |
4 named values |
| OrcaSlicer | enum | not declared | normal(auto) |
4 named values |
| Cura | bool | not declared | on | not declared |
| Creality Print | enum | not declared | normal(auto) |
4 named values |
PrusaSlicer and Cura declare no range for this key, so nothing in the file bounds it.
This value is not a number, so PrusaSlicer, Bambu Studio, OrcaSlicer, Cura and Creality Print declare no unit for it.
The slicers disagree on the type: PrusaSlicer and Cura as bool, Bambu Studio, OrcaSlicer and Creality Print as enum. preslice reads all of them.
Bambu Studio, OrcaSlicer and Creality Print accept the same names: normal(auto), tree(auto), normal(manual), tree(manual).
Every type, default, and bound above is read from the slicer's own field definitions rather than from measurement: PrusaSlicer's PrintConfig.cpp, Bambu Studio's PrintConfig.cpp, OrcaSlicer's PrintConfig.cpp, Cura's fdmprinter.def.json and Creality Print's PrintConfig.cpp.
Can I read it from my own file?
Yes, without installing a slicer. Open preslice and drop a .3mf on the page. It unzips and parses the file in your browser, and shows automatic supports under its own name alongside the rest of the print settings. The file stays in your browser; see what leaves it.