---
jupyter:
  description: 'planex2d faces, wires and sketches exported to OpenCASCADE shapes: exact lines, arcs and B-splines with shared
    vertices, their names and colors kept, with ToOCCShape, ToOCCFace and ToOCCWires.'
---

# To OCC shapes

Faces, wires and sketches become OpenCASCADE shapes with exact lines, arcs, full circles and B-splines, shared
vertices, names and colors. The export needs OpenCASCADE through `netgen.occ` (`pip install netgen-mesher`, which
brings OpenCASCADE as `netgen-occt`). On the way out, the export can apply everything that `Simplify` does. See
[Defeaturing](../../core/defeaturing/index.md) for details.

![A model rocket exported to OpenCASCADE](../../_static/gallery/rocket.png){.preview}

The [rocket example](../../examples/rocket.md) is revolved, lofted and extruded from planex2d sketches.

The example is a plate 4 × 2 with a bore of radius 0.5, with its outline and bore named (Figure 1):

```python
import planex as px

plate = px.QuickSketch((-2, -1)).Rectangle(4, 2, name="outline").Face()
part = plate - px.QuickSketch().Circle(0.5, name="bore").Face()
shape = part.ToOCCShape()
print(len(shape.edges), "edges:", sorted({e.name for e in shape.edges}))
```

```python nbsphinx="hidden"
from docs_figures import Row, Vertices
```

```python nbsphinx="hide-input"
Row((part, "The plate, its bore highlighted", {"highlight": list(part.edges(name="bore"))}),
    caption="A plate with a named bore")
```

## Faces and wires

A face, its wires, or a wire on its own can each be exported as OpenCASCADE objects. The example exports the
plate as a face and as its wires, and a slot of width 1 along a spine of 3 as one wire:

```python
face = part.ToOCCFace()
wires = part.ToOCCWires()
slot = px.QuickSketch().Slot(3, 1).Wire().ToOCCWire()
print(type(face).__name__, len(wires.edges), len(slot.edges))
```

## Everything at a glance

| Object | `ToOCCShape()` gives | Also |
|---|---|---|
| Face | The face | `ToOCCFace`, `ToOCCWire`, `ToOCCWires` |
| Wire | Its wires | `ToOCCWire`, `ToOCCWires`, `ToOCCFace` |
| Sketch | The face of everything drawn | `ToOCCFace`, `ToOCCWire`, `ToOCCWires` |
| Compound | Faces and wires glued together | |