Revit is a powerful tool for creating building information models (BIM) and allows for the creation of 3D views to visualize your design. Adding levels to a 3D view can help provide additional context and understanding of the building's spatial layout. Here are the steps to add levels in Revit 3D view:

1. Open your Revit project and navigate to the 3D view where you want to add levels.

2. In the project browser, locate the levels that you want to display in the 3D view. This can be done by expanding the 'Floor Plans' or 'Sections' categories and finding the desired levels.

3. Once you have identified the levels you want to display, right-click on the level and select 'Show Category' > 'In Current View' from the context menu. This will make the levels visible in the 3D view.

4. To further enhance the visibility of the levels, you can adjust the display settings such as line weight and color by going to the 'Visibility/Graphics Overrides' menu. Here, you can customize the appearance of the levels to better suit your visualization needs.

5. If you want to add additional levels that are not currently displayed in the 3D view, you can do so by navigating to the 'Floor Plans' or 'Sections' categories in the project browser, right-clicking on the level, and selecting 'Show Category' > 'In Current View' as mentioned in step 3.

By following these steps, you can easily add levels to your Revit 3D view and improve the visualization of your building design. This can be particularly useful when presenting your design to clients or stakeholders, as it provides a more comprehensive understanding of the building's spatial organization.

In conclusion, adding levels to a 3D view in Revit is a straightforward process that can greatly enhance the visualization of your building design. By following the steps outlined above, you can effectively incorporate levels into your 3D view and create a more immersive and informative representation of your architectural project.