Create a Model with 3dsMax

You need 3ds Max for this tutorial, also you need to install the ColladaMax export plug in which you can download for free here.
You should put the texture assets in the same folder you export the Collada file.

Export Collada file from 3ds Max

First step: Create a box
Second step: Select export from the file menu
Third step: Select COLLADA as file type and export file
Fourth step: Accept default Collada options

Import Collada file to Twinity

First step: Select the exported Collada file in Twinity
Second step: Wait while it gets checked and converted for upload
Third step: Select place item
Fourth step: Enjoy your new model in Twinity