contain Directional Light or Sun light inside a volume

[Chris__]

I have a perforated hollow box in which I would like to place a directional light. Under the right angle, light will be cast light through these openings, will the rest of the box will block the light. As an affect I will get my 'designed' illuminated patterns on the floor surface. This is inspired by digital sundials, by now with light source inside, instead of using the sun as light source. See for an example of standard sundial with sun: https://gizmodo.com/this-digital-sun...cut-1545753402

When I try to position a direction light, or the sun for that matters, inside the box, it still renders it as though it is outside the box. Casting shadows of the entire box. I cannot use a light sphere, as the light rays need to be directional.

Any suggestion how to make thinks work?

[Svetlozar Draganov]

This is actually expected, Directional Light illuminated the scene from infinity like V-Ray Sun for example, its starting point cannot be specified within the scene.
You can use V-Ray Rectangular Light with Directionality parameter set to 1:

[Svetlozar Draganov]

Can you provide more information why do you need the light inside the box? In the sundial example you provided the light is actually outside of the box not inside.

[Peter.Chaushev]

Hello, Chris,
If you wish to simulate sun light properly, double-check the geolocation and time&date parameters to ensure the light vector is correctly set.

Kind regards,
Peter