yade-dev team mailing list archive

[Bruno Chareyre <bruno.chareyre@xxxxxxxxxxx>]

> What are the things to save within "almost everything" except body and
> interaction lists and their corresponding instances?
O.engines is saved, else reloading would only result in dead lists of
things.

>  Also, your
> saveTmp()and reload() suggestion works with the serialization behind and
> saving to disk or memory?
It saves to memory instead of a file, but the content of what is saved
is exactly the same, it is always based on serialization. It is also
possible to save to a string variable (very similar to saveTemp except
that you explicitely name this string, thus enabling manipulations of
it, passing it to another thread, etc.)

> I should say that interaction deletion and creation in sub steps is the
> main problem, therefore, the change of the structure of the scene.
Yes.
>  At
> this moment I dont think interaction forces are not conservative.
What is the consequence of (non-)conservativity?

> Lastly, is it enough to keep only the interactions and body states
> before integration? If its what are these?
Not sure.
There is also body.shape to save, of course, but you don't have to take
care of that in details as long as you save body.
It could be wise to keep the collider's state in memory since it has an
initialisation that normally happens at iteration 1 and which is quite long.
Since you can't really save the collider's internals, it is a critical
point.
In fact, instead of saving and reloading, why not just keeping the scene
state as it is? Duplicate it and use the duplicate as a working copy,
then update the original based on the last substep. There is no need to
reload it, thus collider is preserved.
Just an idea.

Bruno

 Pzt, 2013-09-30 tarihinde 16:32 +0200 saatinde, Bruno Chareyre yazdı:
>> Hi,
>> Not an easy question.
>> I guess that you have to save almost everything, since substeps will
>> change positions and contact forces.
>> Scene contains everything (exception for local variables and functions
>> defined in your script). It is saved for instance if you type
>> O.saveTmp(). And reloaded with O.reload(). You could probably use that
>> for a start. There are probably more efficient ways but it is hard to
>> imagine without looking at the details of odeint.
>>
>> Bruno
>>
>>
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Bruno Chareyre
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