You must select a design entity, datums, or geometry to work on your model. You can select an entity before or after you activate a geometry tool. Selection filters and collectors control the selection of entities for a geometry tool.

Selection filters narrow the selectable entity types so you can easily locate the entity. When you click a geometry tool, the selection filter displays the entities that you can select for that tool. The best filter is automatically selected.

Collectors gather all the entities that you can select before opening a geometry tool. You can then use these entities as references during modeling operations.