---
title: "Model"
description: "A model is a mesh loaded into a scene, with its placement and its supports."
url: https://developer.formlabs.com/core-concepts/model/
---

# Model

A *model* is a mesh loaded into a scene. An STL file, an OBJ file, or a CAD file
becomes a model when you import it. The model carries everything the print needs from
that part: its geometry, its position and orientation on the build platform, and its
supports.

Each model is one entry in the **Model List** in PreForm. When a customer order
arrives as several STL files, each file becomes its own model, and the model's name
tells you which order it belongs to.

![The Model List in the PreForm side panel with three models named by order number, one of them selected on the build platform.](https://developer.formlabs.com/assets/images/screenshots/model-model-list-order-names.png)

*Each row in the **Model List** is one model, and the row shows the model's `name`.*

## What a model holds

Each model in a scene has its own ID and properties:

| Property | Meaning |
| --- | --- |
| `id` | The model's ID within its scene |
| `name` | The name the **Model List** shows, derived from the filename unless you set one |
| `position`, `orientation`, `scale` | Where the model sits on the build platform, in millimeters and degrees |
| `units` | The units the file was interpreted in, such as `MILLIMETERS` |
| `bounding_box` | The model's extent in the scene, including its supports |
| `has_supports` | Whether the model has supports |
| `in_bounds` | Whether the model fits inside the build volume |
| `original_file` | The path of the file the model came from |

## Import a model

The `import_models` method loads a file into a scene and returns the models it
produced:

**SDK:**

```python
# PreForm reads the file itself, so PART is a full path on the machine that runs
# PreForm.
imported = preform.import_models(scene_id=scene.scene_id, file=PART)
# The import answers with the new models' ids; list_models has the rest. units is
# the unit the file was interpreted in, such as MILLIMETERS.
model_id = imported.new_models[0].model_id
model = preform.list_models(scene_id=scene.scene_id, model_ids=[model_id]).models[0]
print(model.id, model.name, model.units)
```

**curl:**

**macOS:**

```bash
curl -X POST http://localhost:44388/v1/scene/model/import/ \
    -H "Content-Type: application/json" \
    -d "{\"scene_id\": \"$SCENE_ID\", \"file\": \"$PWD/part.stl\"}"
```

**Windows:**

```powershell
@{ scene_id = $env:SCENE_ID; file = "$PWD\part.stl" } |
    ConvertTo-Json |
    curl.exe -X POST http://localhost:44388/v1/scene/model/import/ `
        -H "Content-Type: application/json" `
        -d "@-"
```

PreForm reads the file itself, so pass a full path on the machine that runs PreForm. A
CAD or 3MF file with several parts imports as one model unless you pass
`split_multi_model_file=True`. For more information, see the
[Scenes](https://developer.formlabs.com/api-reference/scenes.md) endpoints.

To label each model with an order number, pass `name=`. An STL file carries no units,
so PreForm reads it as millimeters. For a file a customer designed in inches, pass
`units=ImportUnits.INCHES`, from `formlabs_preform_api.models`.

The `import_models` method loads STL, OBJ, and 3MF mesh files, and CAD files in STEP,
SolidWorks, PTC Creo, JT, CATIA V5, Inventor, and Rhino formats. For more information,
see [Opening a model in PreForm](https://formlabs.com/support/Opening-a-model-in-PreForm/).

## Supports belong to the model

On SLA printers, a model prints on supports. Supports consist of three parts: the *raft*,
which adheres to the build platform; the *scaffolding*, which rises from the raft; and
the *touchpoints*, where the scaffolding meets the model:

![A bust in PreForm on its supports. Label 1 marks the touchpoints, label 2 the scaffolding, and label 3 the raft on the build platform.](https://developer.formlabs.com/assets/images/support/bust-with-numbers-preform-3-0.png)

*Touchpoints (1), scaffolding (2), and the raft (3).*

The supports are part of the model, so they move with it, and its bounding box
includes them:

```python
preform.auto_support_models(scene_id=scene.scene_id, model_ids=[model.id])

# The supports belong to the model, so its bounding_box includes them.
for listed in preform.list_models(scene_id=scene.scene_id).models:
    print(listed.name, listed.has_supports, listed.in_bounds, listed.bounding_box)
```

Orientation affects how much support a model needs, so orient a model before you
support it. For more information, see
[Model orientation best practices for SLA printing](https://formlabs.com/support/Model-Orientation/)
and [How supports work in SLA printing](https://formlabs.com/support/How-supports-work-in-SLA-printing/).

## What's next

- [Validate](https://developer.formlabs.com/core-concepts/validate.md)