It's not free I think it's about 35$ the newest version has a DTS exporter built in you don't have to download a separate exporter. The good news is there is a 30 trial so you can try it out before you buy it and see if you like it. Alternatively you could use blender to model for blockland it's free but it has a steep learning curve, if you want to use that just send me a personal message and I'll send you some good tutorial information.
