# Simplifying the Slope Boundary

When model geometry is imported into **RocFall** from other sources (e.g., DXF files), it is quite common that boundaries are defined by an unnecessarily large number of vertices. This may occur for a number of reasons, e.g., manual digitizing procedures, creation of 2D sections from 3D geometry, etc. When boundaries have an excessive number of vertices, it can lead to modelling and analysis issues (e.g., difficulty editing boundaries, increased compute times, etc.).

The **Simplify Slope** option allows you to reduce the number of vertices on a boundary according to a user-defined criterion so that the new boundary has fewer vertices but still adequately defines the model geometry.

To use Simplify Slope:

- Select
**Simplify Slope**from the**Slope**menu.

You will see the**Simplify Boundary**dialog.

There are two options for defining the degree of simplification:- Percentage of original number of vertices - this option will reduce the number of vertices on each selected boundary to approximately the specified percentage
- Distance from original boundary - this option will remove vertices on each selected boundary, which are LESS THAN the specified distance from the original boundary

- Choose the desired criterion and enter a value of percentage or distance. You can select the
**Apply**button in the dialog to see the results without closing the dialog. - When you are finished, click
**OK**and the slope will be simplified according to your input.

#### Notes:

- The default Percentage of Original Vertices is 20%.
- The default simplification option is to simplify by Percentage of Original Vertices.
- If you are not happy with the results (e.g. your model has been altered unexpectedly, due to the removal of too many vertices) you can always select Undo to reverse the changes.