Dynamic properties back to default after update

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geerten
Posts: 77
Joined: 14 Feb 2013, 13:57

Dynamic properties back to default after update

Post by geerten »

After updating my scene from 3.01 to 3.02, almost all my dynamic properties were back to default. So I lost my friction, custom collision margin, etc. They were all back to default. It took me quite some time to figure out that this happened..

coppelia
Site Admin
Posts: 10339
Joined: 14 Dec 2012, 00:25

Re: Dynamic properties back to default after update

Post by coppelia »

Hello Geerten,

This is very probably linked to your previous problem. Could you confirm that setting the parameters to what you had in the past solved the problem you mentioned in another post?

What actually happened is following:

In version 3.0.1 there was a small bug that would affect some shapes: the convexivity tolerance was a little bit too large. We corrected for that in release 3.0.2 by recomputing the "convexivity" flag for all shapes. This operation had as indirect consequence the reset of 2 parameters:
  • the Bullet collision margin factor
  • the Bullet non-default collision marging factor

The above reset is unfortunate but happens only once (when going from a version older than 3.0.2 to a version newer than 3.0.1)

But you mention that the friction coefficient was also reset. This should not be the case. Could you please confirm that the friction was not affected and that your previous problem is solved?

Cheers

geerten
Posts: 77
Joined: 14 Feb 2013, 13:57

Re: Dynamic properties back to default after update

Post by geerten »

Hello,

It would be nice if things like these would be announced in the release notes :S

This did not solve the problem I previously mentioned. I'm still not pleased with the results of the simulation in comparison to before. Not only on the rollers, but also other points are less realistic than they used to.

For example there is a certain 'strip' (of stainless steel) on top of the second conveyor belt. In the previous version, the eggs would bump against it, and start spinning until enough pressure from behind would push it over. What I'm seeing now is that they do not spin, but also need much more pressure than before. Both of these points are not realistic. Do you have any clues to what I have to change to get it back to the previous behavior?

The friction coefficient was also most definitely reset to 1 again.

geerten
Posts: 77
Joined: 14 Feb 2013, 13:57

Re: Dynamic properties back to default after update

Post by geerten »

What I'm noticing now is that if I load my scene (saved from version 3.02) in 3.01, that my eggs (produced by a partsProducer principle from blob detection pick and place example) are non convex and they are convex in 3.02 (because they are morphed into convex shapes).

coppelia
Site Admin
Posts: 10339
Joined: 14 Dec 2012, 00:25

Re: Dynamic properties back to default after update

Post by coppelia »

Hello Geerten,

We mentioned this change in the very first point of the new release: here.
We cannot possibly enter into details for every changes we make, since that would require to write a book everytime ;)

When mentionning specific things that other people do not know (i.e. your simulation problem with eggs, etc.), you can also write us directly (this also because you are a customer).

We will look at the problem within a few days.

Cheers

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