Duplicate seed value on network renders.

Duplicate seed value on network renders.#367064

By Gary Bidwell - Fri Apr 12, 2013 11:36 am

- Fri Apr 12, 2013 11:36 am #367064

Hi,

We have rendered on 22 machines (via qube), and had 2 renders with the same CPU ID (seed). And again rendering on 34 machines. This is happening almost daily.

You possibly need to increase your random seed count look-up. Only numbers between 1 and 16383 being used? leaving high probability of duplicate seed value.

>> Error: ID CPU must be between ( 0 - 16383 )

Any fix for this?

Thanks.

Re: Duplicate seed value on network renders.#367075

By Bubbaloo - Fri Apr 12, 2013 3:36 pm

- Fri Apr 12, 2013 3:36 pm #367075

That's very strange. I've rendered hundreds of co-op renders on our 15 node system and never experienced duplicate seeds. The variable in the equation may be Qube.

Brian Looney
Maxwell + RealFlow
http://www.turbosquid.com/Search/Artists/Bubbaloo
Help! I'm dispersing into a haze of probability!

Re: Duplicate seed value on network renders.#367131

By Gary Bidwell - Mon Apr 15, 2013 3:00 pm

- Mon Apr 15, 2013 3:00 pm #367131

No it's not Qube. this is just a pass through for the command line.

Initially we were hoping to circumvent the 16383 limit that is imposed when using -seed flag via command line (OSX) maybe using BASH random would give us a better algorithm.

When submitting jobs via the OSX command line using -seed flag the upper limit is 16383 otherwise it errors with the below.

error : >> Error: ID CPU must be between ( 0 - 16383 )

As we don't use maxwell render manager only command line (qube) each machine receives the exact same command independent of the other with no knowledge of which seed number has already been used. This enables the same seed value to be generated which may well be different than when using Maxwell's own manager. (error check?)

Why is there a limit and why so small when rendering this route?