Top-down proper sun lighting render without roof

[krullert]

Hi,

Is there a way to render a level top-down, not showing the roof but rendering it in a way that sun lighting is rendered as if there is a roof?

Example of the unwanted situation;


Example of the wanted situation (on a lighting perspective that is, this should be topdown with the same lighting)

[krullert]

Images were removed from the original upload site, heres a re-upload (question is still valid);

Example of the unwanted situation;


Example of the wanted situation (on a lighting perspective that is, this should be topdown with the same lighting)


Additional explanation on why I would like this;
Goal is to create a program (based on sweethome3d) that can generate lightning in a house's topdown view, as the sun shadows would cast is over the complete year. This enables fun things like fancy dashboards with home-automation (e.g. home-assistent) that shows the simulated sun lightning for each day of the year.

[Puybaret]

It's not possible. Lighting works like in real life. Opening the cover of a box will let light enter in it.

[freeman69]

Sorry to respawn this thread.

But I don't think it's impossible.
We could use an invisible "one way" ceiling

When casting rays, hits above the ceiling should be ignored and hits below the roof thow be ignored

I'm actually a developper working in computer graphics.

Another thing is consider a surface with an inside material and an outside material. This way we could have a fully transparent material above.

It's should not be a very long thing to do depending on how it's manager in Sunflow/Yafaray and Sweet Home 3D

So my questions :
Is it something possible to do (I mean legally/pratically)
I know yafaray is Open Source.
Are you using some flavour of the original project ?

Thanks, in advance


Render