Hi Jesper, MoI itself is focused just on modeling, not on generating animations or doing renderings with transparency.

So you'll need to use a different rendering program in order to do those parts of what you're asking about.

You might want to take a look at Simlab composer, it may fit what you need, they have a trial version here:
http://www.simlab-soft.com/3d-products/simlab-composer-main.aspx

If your model is simple enough you may be able to do the whole thing inside of of Simlab. If you need more detailed modeling, then MoI can be useful for creating the model and then you would export it out from MoI in OBJ format and then import that into Simlab for rendering and animation in there.

re: freeware programs - just sort of due to the nature of things it's not very common for freeware to also be intuitive and simple to use. The main freeware animation program is called Blender: http://www.blender.org/ . Maybe check out Anim8tor too: http://www.anim8or.com/main/index.html

- Michael