> For the complete documentation index, see [llms.txt](https://help.vectary.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.vectary.com/documentation/design-process/edit-mode/cap-open-boundaries.md). # Cap open boundaries The **Cap Open Boundaries** tool fills open holes in geometry by generating new faces along the boundary edges, ensuring a closed mesh. #### How it works * Select an open boundary (hotkey `O`) * Press **`Ctrl+O`** to activate the tool * A new face is automatically created, capping the selected boundary {% embed url="" %} #### Use Cases * Closing gaps in a mesh to prepare it for further modeling. * Ensuring a watertight mesh. * Simplifying manual face creation by automatically generating a cap over open boundaries. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://help.vectary.com/documentation/design-process/edit-mode/cap-open-boundaries.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.