@Kadri - very strange
@Dune - It looks like the cube youíre using originated within Terragen, e.g. it wasnít imported using the obj reader. I tried the same, just setting render to invisible and leaving cast shadows checked, and got the same results as you. Seems like itís just the obj reader thatís giving me trouble.
I did a new test, exported a new cube from maya, imported it into terragen with the obj reader. It seems like even when I change the cubeís settings, nothing updates in the actual render (see attached).
At a lossÖ I feel like thereís just some setting ticked somewhere that is doing this, or i'm missing something really obvious... Sort of hard to troubleshoot if itís working for everyone else. Using the pro version of tg4, btw.