To me 3 hours seems quite a long time to fill with just spoken information
and slides. If the group is not too large, maybe you can add some
'experience' in it. For example let the group do some measurements, walk
through the building or outside, and let them collect data from lights and
objects etc. Thereafter you show how one can use such data in lighting
simulation. Beside the theory and technology, let them experience the
practice. Just a thought,
I've been asked to give a talk on on the basics of lighting simulation,
Radiance, and perhaps simulating electric light.
The victims, er, audience for this are a group of architecture students in
an electric lighting class, run by an architect and lighting designer. I
have three hours, though I don't have to use them all. I intend to reserve
at least some of the time for questions.