I have a question, which I can't really google since I don't know the words for it.
I use IBL in rhino to illuminate my scene. It give me really good results, but I can't figure out how to add ground shadow, so that it looks like my object is standing on the ground, like in this examples:


They are done in Rhino, but with another external render engine.
The attachment is what I was able to make.
What do I have to do to achieve this? Searching for IBL + shadow, or HDRi doesn't help anymore.
Thanks in advance.