# Revolution

This example demonstrates creating a more complex axisymmetric geometry using a revolution operation.

![Revolution geometry example](/_static/FIGURES/salome9.jpg)

## Setup

```bash
mkdir -p TRUST_tutorials/salome/exo2
cd TRUST_tutorials/salome/exo2
$PathToSALOME/salome &
```

- Create a new study: File → New
- Select the Geometry module

## Creating Points

Go to: New Entity → Basic → Point

Create the following vertices:

| Vertex | X | Y | Z |
|--------|---|---|-----|
| Vertex_1 | 0 | 0 | 0 |
| Vertex_2 | 1 | 0 | 0 |
| Vertex_3 | 1 | 0 | 0.3 |
| Vertex_4 | 0.75 | 0 | 0.3 |
| Vertex_5 | 0.375 | 0 | 1 |
| Vertex_6 | 0.75 | 0 | 1.6 |
| Vertex_7 | 1 | 0 | 1.6 |
| Vertex_8 | 1 | 0 | 2 |
| Vertex_9 | 0 | 0 | 2 |

Click "Apply and Close"

  ![Points created](/_static/FIGURES/salome7.jpg)

## Creating Edges

- **Create straight lines:** New Entity → Basic → Line
  - Line_1: Vertex_1 to Vertex_2
  - Line_2: Vertex_2 to Vertex_3
  - Line_3: Vertex_3 to Vertex_4
  - Line_4: Vertex_6 to Vertex_7
  - Line_5: Vertex_7 to Vertex_8
  - Line_6: Vertex_8 to Vertex_9
  - Line_7: Vertex_9 to Vertex_1
  - Click "Apply and Close"

- **Create an arc:** New Entity → Basic → Arc
  - Arc_1: Vertex_4 → Vertex_5 → Vertex_6
  - Click "Apply and Close"

## Creating the Revolution Solid

- **Create a wire:** New Entity → Build → Wire
  - Wire_1: Select all lines (Line_1 through Line_7) and Arc_1 (use "Ctrl" for multi-selection)
  - Click "Apply and Close"

- **Create a face:** New Entity → Build → Face
  - Face_1: Select Wire_1
  - Click "Apply and Close"

- **Create the revolution:** New Entity → Generation → Revolution
  - Name: `Cylinder_1`
  - Objects: Face_1
  - Axis: Click the arrow button and select "OZ" from the Object Browser
  - Angle: `360°`
  - Click "Apply and Close"

  ![Revolution result](/_static/FIGURES/salome8.jpg)

## Creating Boundary Groups and Mesh

- **Create boundary groups:** New Entity → Group → Create Group
  - Follow the same procedure as in the cylinder example

- **Save your study:**
  - HDF format: File → Save/Save As...
  - Python format: File → Dump Study...

- **Create the mesh** following the same procedure described in the cylinder section

```{note}
The solution file (`revolution.py`) is available at: `$TRUST_ROOT/doc/TRUST/exercices/salome`
```