You (kind of) have both options!

Within Arena you’d be looking at presenting “live” from Arena, there’s no internal way of recording the warped output.

You can of course use an external recorder (hyperdeck etc) to record once and then playback from hardware.

That’s a really neat way of doing it! I’d have gone straight for a third layer, your way is much more efficient.

Is there any benefit from having two of those super expensive GPU’s? everything I’ve read says the second card will be just used as an output extender.

You can use an external controller (artnet, midi, osc) to trigger columns at specific times. With a bit of tinkering you can usually run the external trigger software on the same pc!

Overlay like Alpha channel overlay?

Failing to answer your original question, I have to ask can the three videos not be all played from the one Mac? Using a Datapath or triplehead on one output you could then have three perfectly synced videos.

Doesn’t have to be one fixture though... and doesn’t have to have concurrent DMX addresses. You could patch four rgb fixtures that then control “colourise” effects on four different layers of all you want to control is colour. Or if you wanted to just control position of a single graphic you could p...

The idea is that rather than having “a fixture” you can create your own and just control the attributes you want to. I use Chamsys, and quite often patch two or more different fixtures on my lx desk, for example I might patch a three channel rgb (generic ltp LED) fixture and use that to control the ...

Does toggling between straight or premultiplied alpha type make any difference?

you should find your licenc inside your Account on this page here.... http://resolume.com/shop/account.php There you can deregister your software and free it this way. If you dont find it there then hurry and drop a mail to resolume. I bought this series through the resolume distributor in Jakarta ...