Alpha Rounding Error?

[aweidenhammer]

I have a scene here that is rendering on a farm with the service pack installed. Some random frames (from different machines) are rendering with alphas that are just slightly below 1. ranges from .965 to .978

Obviously, this is causing comp issues (flickers) that we have had to resort to using a clamp node to push all alphas above .95 to white. This looks to me like an odd rounding error, but it took me a while to track down since I thought at first it was my zdepth.

Andrew

[vlado]

Is it consistent relative to the frame number (e.g. does a given frame always have lower alpha)? Would it be possible to get me a scene with this problem to vlado@chaosgroup.com?

Best regards,
Vlado

[aweidenhammer]

We're still digging on this one. What I thought was random machines, actually seem to be only 4 machines of the entire farm. Trying to see what the hell happened, but our install script might have burped, or something. I'll let you know what happens with the renders over the weekend. At least I can just blacklist those 4 for the real render! Thanks,

Andrew