This is another cool way on how to get your 3ds objects. Sketchup is obsolete, PCon Planner is the new darling. Check the video below on how to get the best low poly objects using PCon Planner. And what's more? It is a free software! No expiry date to convert your 3ds files. Its unlimited!
Just follow the simple instruction in the video on how you will simply convert the objects from 3DWarehouse or other 3d websites to .3ds files which are very helpful in your lighting design calculations.
Enjoy learning!