You will need A7 Comm or A6 Pro to use motion blur.
You can find a simple solution for fullscreen blur on the wiki.
If you´ve got only A6 Comm, you could use Sylex (There is a fullscreen blur included (You could combine the blurstrength with the mousemovement to archive some kind of motion blur for the camera)).
If you want to get real motion blur, you will need a postprocessing shader (it is the same with the sylex blur).
It could be possible to change the Depth of Field shader (created by BoH_Havoc), to a real, working motionblur shader.

Or just look through the internet for a shader and make it usable with 3DGS.

I don´t think that there is a real motion blur shader for 3DGS yet.


Slin