View Full Version : Screamernet and expressions... I need a clue

03-02-2006, 03:31 PM
I have a scene that seems to be cursed. Lightwave simply does not want me to finish it. The fact that I even got to the render stage considering what Lightwave has put me through is a miracle, but it's also beside the point.

The scene involves a fairly realistic character with a staggering amount of expressions used throughout for everything from bone rotations, to IK, to morph mixing. If I render a sequence straight out of Lightwave (F10), everything turns out fine. If I attempt a screamernet render, all of the expressions are ignored. All of them. Even motion modifier plug-ins such as 'Follower' are ignored. The character ends up moving like some sort of demented Frankenstein's monster.

I'm wondering if anyone can think of any reason why screamernet would behave this way. Are the expressions supposed to be saved somewhere and screamernet just can't find them? It's as if there is an 'apply expressions' button somewhere that has been switched to 'off'. I've confirmed that screamernet will render motion modified by expressions on a much simpler scene I built as a test, so there must be something odd about that one particular scene that screamernet doesn't like (the curse).

Anybody ever come across this before? Any ideas what I could look into? It would take months to render this scene pass by pass, shot by shot via F10, but I've come too far to give up on it now.

03-02-2006, 03:49 PM

I do not remember that expresions needed of any plugin, but that follower it is failing, sounds to me that your render nodes are not finding the plugins of LightWave.

Hope that clue helps.

Best regards,

03-02-2006, 04:26 PM
No shortage of plug-ins in this scene - Sasquatch, G2 and Smartmorph among them, but screamernet has no problem finding those. The 'cmdline' files for the render nodes all have the correct path to the preferences folder. As I said, everything else seems to work just fine - and everything works perfectly well from Lightwave, which accesses the same preferences folder.

I agree, though, that something is not getting through to the nodes. Can't figure out what.

03-02-2006, 04:42 PM
expression work fine in screamernet, but if you have strange problems, bake all motion and you are sure that you not have surprise at final render.

03-02-2006, 06:20 PM
I've been trying that, and it presents its own set of problems. There are so many expression-driven bones, morphs etc. that if I try to bake them individually (or with motion mixer), I always miss a few and things get screwed up.

I have applied MD_scan to all the deformed objects which seems to work well, except I've used Whirleypoints fairly extensively and I can't get MD_scan to capture Whirleypoints displacements on named surfaces. I'm currently in contact with Worley labs in hopes that they can help me figure this out, as right now, it appears to be my best option.

Did I mention the curse?

Steve Reeves
03-03-2006, 04:02 AM
Just a hobbyist here - fairly new to screamernet too - so this may not be of value.

To double check the plugin paths and plugin availability something that might be useful is DStorm's render manager. If you set this up for one scene on a node using the share paths for your paths to the plugins and so on you can use it's check scene to tell you if it cannot see any of it's plugins. If it can't it tells you which ones it can't see.

Might help in that it just makes it easier to see what plugins exactly are causing grief.

Best wishese for solving your problem.

03-03-2006, 08:22 AM
I'd debug this like many programmers do.

First make sure expressions are working with your render farm. A couple of nulls should do it. Then repeat for each of the plugins you are using. That should track down the bugger.

If everything is working then it's a combo-problem and you need to find it.
Copy the entire scene & all objects so you can safely hack away.

Take away half of the objects or bones. This is the divide and conqueor strategy: you keep taking away half of the scene/bones/lights (whatever) until things start working. It may work in an ugly way - but at least you'll know that the last deleted piece is causing the problem.

Once you've identified that problem-piece: start dividing it until you find the expression or plugin that is the culprit.

I've just started using expressions myself. I'm wordering if you have a reference to a previous frame in an expression that can't be resolved in SN. Maybe that's causing some kind of cascade expression failure.

I'll be watching this thread to see what you find out.

03-03-2006, 09:34 AM
I understand totally where you're coming from. That is clearly the most effective 'brute force' way of hunting down the problem and killing it (I have already confirmed that expressions, in general, have no problem rendering through screamernet). It also seems, however, to be the most time consuming and complex path to take - basically a last resort. My priority is simply finding the most expedient route around this problem.

The thing is that after much struggle and sweat, I've finally got the scene working and rendering flawlessly out of Lightwave. Debugging it to render the same way via screamernet could conceivably take much longer than either scanning/baking the deformations via MD_scan (if I can get the Whirlypoint problem figured out), or simply installing Lightwave on all my nodes and loading render scenes individually on each machine. The latter, of course involves manually swapping the dongle between machines to get the renders started and manually loading another scene/pass as each one finishes. Exactly the kind of render nursing that screamernet is supposed to alleviate.

Long story short, I'd LOVE to figure this out, but if it's possible and faster to sidestep it altogether... then that's the way I'm going. Next time around I'll be much more conservative in my use of plug-ins and widgets.

At least, that's the way I feel right now. Maybe I'm just tired.