How to remove door and window lines in 3D

Issue description

You have just created a lovely 3D view ready to render but you realize each opening element is showing an opening line ruining the look of the image

Solution

1. In the Model View Options dialog, go to the "Miscellaneous Settings for Library Parts" panel.
2. Use these controls to set the display of opening lines for each opening type, door, window, or object.
3. Uncheck the checkbox in the "Show Opening Line in 3D" field to remove the lines.

Please note:
Since this is an Model View Option setting, it is stored with the view. So if it's not saved, it may change when another view is activated.