For adding objects, either in TGO (native) or OBJ format, go to the Objects layout using the button at the top of the interface. Then click the Add Object button on the left, go to Object->OBJ reader or TGO reader. You will have to place each object manually. An easy way to do this is to find where you want to put it in the scene then put your mouse cursor over that point in the 3D preview, right-click and copy coordinates, then go to the properties of that object node and paste into the location coordinate box using the past button on the right (looks like a little clipboard).
- Oshyan