# About hypotheses

Hypotheses represent boundary conditions which will be taken into account at calculations of meshes or submeshes basing on geometrical objects. These hypotheses allow you to manage the level of detail of the resulting meshes or submeshes: when applying different hypotheses with different parameters you can preset the quantity of meshing elements which will compose your mesh. So, it will be possible to generate a rough or a more refined mesh or submesh. In SMESH there are the following basic hypotheses:

- For meshing of edges:

- Arithmetic 1D

- Average Length

- Deflection 1D

- Number of segments

- Propagation of 1D Hypothesis on opposite edges

- Start and end length

- For meshing of faces:

- Length from edges

- Max Element Area

- Non conform mesh allowed

- For meshing of volumes:

- Max Element Volume

The choice of a hypothesis depends on:

- the geometrical object (shape) which will be meshed

- the algorithm, which will be selected for meshing of this geometrical object (shape)

To create a hypothesis

In the main menu select Hypotheses > Create hypotheses

The following menu will appear:

Select one of the menu items and click Create. A data input dialog box corresponding to the chosen type of the hypotheses will appear. The created hypotheses shall appear in the Object Browser under the Hypotheses folder: