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robcat2075

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A/B comparison of slightly different results between two different beta versions of A:M, but also on two different CPUs, a Q6600 and a Core i5-3470.

Same settings but somehow the cloth settles a bit differently.

ShirtCompare.gif

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1 hour ago, robcat2075 said:

A/B comparison of slightly different results between two different beta versions of A:M, but also on two different CPUs, a Q6600 and a Core i5-3470.

Same settings but somehow the cloth settles a bit differently.

ShirtCompare.gif

Shouldn't a physics simulation be a bit different every time? Like if you drop a shirt in real life it wouldn't land exactly the same every time. Or isn't that how the A:M simulation works?

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That would not be helpful.
Think about what would happen if you would have to rerender a small part of it in half a year.

In the end there is baking for such scenarios because it was not exactly like that anyway, but the closer to the original the better :).

Best regards
*Fuchur*

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58 minutes ago, Wildsided said:

Shouldn't a physics simulation be a bit different every time? Like if you drop a shirt in real life it wouldn't land exactly the same every time. Or isn't that how the A:M simulation works?

I don't know!

I don't know if Simcloth has any random element to how it makes decisions.

My presumption is that, no, it doesn't. 

We get different results from dropping a real cloth because it is impossible to hold and drop it exactly the same each time, and after you drop a cloth once it can never truly be returned to its pre-dropped condition. It is also an uncountable set of points acting among each other.

Simcloth is a finite set of points, each of which can be exactly defined in all regards along with the forces that act on each.

So i would expect the process to be exactly repeateable. I would want that so that as i search for cloth settings i know that something doesn't work for reasons other than random chance.

Maybe it has something to do with the (im)precision of floating point numbers?

One thing that is different about the two cases is that my old CPU didn't have the SSE4 extensions that A:M can use if they are there, but my new CPU does.

??



 

 

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Damned if I know, Robert. The science and maths behind how these things work is way beyond my skill set. 

I see where you and Gerald are coming from, though. It would be very inconvenient to not be able to reliably recreate an effect due purely to random chance.

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