Strange Alt + B funtion in 2.40

In object mode Alt +B and box select part of the object.

This will cut out the unselected part and also produce an infinately long grey “bounding box” effect.
What is this function?

It apperas to me to be used to hid certain parts of objects or the outsides of an object to allow you fo focus on that object.
another fincutin coulb be to allow you knwo viwe exactly what the selected area would look like in a camera.

Hit Alt-B and select a portion of a model in object or edit mode, then hit G and move your mouse. Then do it from the camera and see the camera disappear.


It never occurred to me to try to move the mesh
But that’s an interesting effect, a sort of window/tunnel view of a portion of the mesh

If you mean, do it in the camera viewport and the camera outline disappears.

Do you envisage a use, yet, for it, other than a peculiar hide command

I think it’s meant more as an aiming and alignment tool and visual aid; any object in the scene is only visible in that cone-shaft. So, you can make a Lamp the camera with Ctrl-O and use Alt-B to “see” a cone of light, specially useful for Shadow only lamps and Negative lamps. Though, we’ll wait and see what they say the purpose is to be.