Using the STL/FBX files is a little more tricky but if you're opting for this method then i'm assuming you know what you're doing. If you don't then here's how i do it:
- Open Blender
- Create new Blender file
- Delete camera, light and cube
- Set units to mm (the deskmat is 900x400mm)
- In the top menubar
File > Import > Import Stl
- Select the 2 files from the downloaded directory
- (Optional) I set the scale to 0.001 initially to get it somewhere near normal on import
- Once they're both imported select them both and scale correctly
- (Optional) Select the edging object in the viewport, right click and select "Shade Smooth" to get it all looking clean and tasty
This should now have the desk-mat sitting pretty in the middle of your scene. Add a surface for the desk-mat to sit on, create your materials (follow the same steps in the "Using the Materials" section if you don't know), light the scene, add a camera and off you go!