[Bf-committers] Repeatable random numbers and distributed rendering on untrusted computers

Ton Roosendaal bf-committers@blender.org
Sun, 30 May 2004 13:02:37 +0200


Hi,

Yes, I should check on it again, to verify each frame rendered uses a  
fixed seed (for example based on frame number). In the past there was  
hardly any real random in Blender, so it didn't give much problems. For  
example particles and flares have a 'seed' for that reason.

Noise in shadow and AO render code however, can be quite difficult to  
be enforced to give a 100% cross-platform result. Even the slightest  
difference in a floating point (math lib) calculation can completely  
change the entire picture then. With tests being done with optimizing  
this will be even get more complex.

-Ton-

On Saturday, May 29, 2004, at 14:32 Europe/Amsterdam, Hans Lambermont  
wrote:

> Tom Musgrove wrote:
>
>> Would it be possible to have an option for repeatable random numbers?
>
> I think so; the random number generator in Blender uses a seed which we
> can control. That way we have repeatable random numbers that are even
> platform independent.
>
> -- Hans
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Ton Roosendaal  Blender Foundation ton@blender.org  
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