# Extruding Mesh Parts along a Spine

This task shows you how to extrude a mesh part along a spine.

You will see here how to:

### Create a 2D mesh from a 1D mesh

Open the Sample02.CATAnalysis document from the samples directory.

1. Click Extrude Mesher along Spine in the Mesh Transformations toolbar.

The Extrusion along Spine dialog box appears.

• Mesh Part: lets you specify the mesh to extrude. Multi-selection of mesh parts is available.
• Remove: lets you remove a selected mesh part from the Mesh Part field.
• Remove all: lets you remove all the selected mesh parts from the Mesh Part field.
• Transformation
• Axis: lets you specify the axis along which you want to extrude the mesh part.
• Start: lets you specify the start value of the extrusion.
• End: lets you specify the end value of the extrusion.
• Anchor point: lets you specify the reference point on the spine for the extrusion.
By default, the anchor point is the projection on the spine of the center of gravity of the mesh to be extruded.
• Distribution:
• Type: lets you choose the node distribution type:
• Uniform: the distance between all the distributed nodes will be the same.
• Arithmetic: the distance between the distributed nodes will be defined by an arithmetical distribution.
• Geometric: the distance between the distributed nodes will be defined by a geometrical distribution.
• Layers number: lets you specify the number of layers you want. Note that this value determines the mesh size. For example, if the distribution is uniform, the extrusion length value is 30mm and the Layers number value is 6, the mesh size value will be : 30mm / 6 = 5mm.
• Size ratio: lets you specify the common difference value for an Arithmetic distribution or the common ratio value for a Geometric distribution. This option is only available if you selected Arithmetic or Geometric as Distribution Type option.
• Symmetry: lets you specify if the distribution should be symmetric or not. This option is only available if you selected Arithmetic or Geometric as Distribution Type option.
 Symmetry option deactivated: Symmetry option activated:
• Capture: node capture is automatically done between the parent mesh part and the extrude mesh part.
• Condensation: if selected, this option lets you condense nodes of the extruded mesh part and updated neighboring mesh parts using a tolerance value.
• Tolerance: lets you specify the tolerance value of condensation (only available with the Condensation option).
• Initialize: lets you automatically initialize the tolerance value of condensation if the Condensation check box is selected.
The tolerance is initialized with the smallest size of element edges among all the loaded mesh parts.
 The tolerance initialization does not take into account 1D elements.
• Check: this button is active as soon as you click the Apply button. This button lets you check, using the tolerance value, if there are intersections or interferences between the extruded mesh and the captured mesh parts (only available with the Condensation option).
To know more, refer to Checking Intersections / Interferences.
2. Select the 1D Mesh.1 mesh part in the specification tree.

3. Set the desired parameters in the Extrusion along Spine dialog box.

 In this particular case: Select Spline.1 in the specification tree as Axis option. Enter 0mm as Start value. Enter 100mm as End value. Select Arithmetic as Distribution Type option. Enter 10 as Layers number value. Enter 3 as Size ratio value. Clear the Symmetry check box if needed.
4. Click Apply.

 An Extrusion Mesh Along Spine.1 object appears in the specification tree and a 2D extrusion along spine mesh part is created. The Extrusion along Spine dialog box is still displayed.
5. Select the Symmetry check box.

6. Click Apply and then OK.

### Create a 3D mesh from a 2D mesh

Use the CATAnalysis document you have obtained at the end of the Create a 2D mesh from a 1D mesh scenario or open the Sample02_1.CATAnalysis document from the samples directory.

1. Click Extrude Mesher along Spine in the Mesh Transformations toolbar.

 The Extrusion along Spine dialog box appears. To know more about the Extrusion along Spine dialog box, refer to Create a 2D mesh from a 1D mesh.
2. Click the 2D mesh part you want to extrude.

 In this particular example, select the Extrusion Mesh along Spine.1 mesh part in the specification tree.
3. Set the desired parameters in the Extrusion along Spine dialog box.

 In this particular case: Select Spline.2 in the specification tree as Axis option. Enter 0mm as Start value. Enter 30mm as End value. Select the Anchor Point check box. Select the point on the spine as shown below. Select Uniform as Distribution Type option. Enter 6 as Layers number value.
4. Click Apply.

 An Extrusion Mesh Along Spine.2 object appears in the specification tree and a 3D extrusion along spine mesh part is created. The Extrusion along Spine dialog box is still displayed.
5. Select Geometric as Distribution Type option.

6. Enter 6 as Layers number value.

7. Enter 4 as Size ratio value.

8. Click Apply and then OK.