ITEM Tutorial Step 3

Step 3: Remove Small Features

• Click Prepare Geometry
• Click Run Checked Diagnostics: The red exclamation point indicates a problem area that may need to be addressed

• Click on Remove small features
• Click on the button with three dots (...) next to the small curve length input box. This will open the small feature size panel. The small feature size panel is a tool to help the user find an appropriate small feature size. The smallest feature size is the smallest detail in the model that needs to be resolved in the mesh. It is also used for several calculations and diagnostic tools in the geometry ITEM panels. Any feature that is smaller than the smallest feature size will be flagged as a small curve or surface, and will need to be removed.

• Click on Find small features
• Change the Number to 20
• Click on Find Small features again. One important thing to note is that the smallest features will only include vertex-vertex and vertex-curve pairs on the same volume. The small gaps and misalignments between volumes will be addressed during the imprinting and merging step.

In addition to setting the small feature size, the smallest feature size panel of itself is a useful tool for visualizing and grouping small features. Sometimes it is useful just to have a list of the smallest features and a means of quickly visualizing and grouping them.

• Scan through the vertex-vertex pairs on the list. Right-click on any of the entities on the list and select Zoom to Pair or Fly-in to zoom in on the small feature.
• Locate pair Vertex 75 and 74
• Clicking on the pair should populated the small feature size input box and the bottom of the window.
• Click Done

• You should now be on the Remove Small Features page. Click Detect small features. There should be 4 small surfaces on the list.
• Click on the plus sign to open the Small Surfaces group. The first four surfaces are small filleted surfaces that are easily removed.
• Click on Surface 10
• Click on Remove Surface from the Solutions window
• Click Execute

• Repeat for Surface 18, Surface 16, Surface 35

• On the 4th small surface execute the Rebuild Topology solution. The rebuild topology option will remove curves or surfaces from a model and reconstruct the geometry using real geometry operations. In this case, it replaces the sharp lip surface with a gradual surface, as shown in the following image.

• The rest of the small curves in the model are at the small feature size limit of 0.25. To remove these from the list, either change small feature size to a smaller value like 0.24, Or click Mark ALL as Okay
• Click Done to return to the main Prepare Geometry page