Re: [Yade-dev] [Bug 850864] Re: strange facet-sphere behaviour
The bug holds for the spheres on the edge. For the other ones (or for all when there is only one facet), there is no bug. See my reply in the answer. -- You received this bug notification because you are a member of Yade developers, which is the registrant for Yade. https://bugs.launchpad.net/bugs/850864 Title: strange facet-sphere behaviour Status in Yet Another Dynamic Engine: New Bug description: See https://answers.launchpad.net/yade/+question/171223 Spheres that are exactly on an edge between facets behave strangely. Maybe related to other (closed, but never solved) bugs in sphere- facet. To manage notifications about this bug go to: https://bugs.launchpad.net/yade/+bug/850864/+subscriptions ___ Mailing list: https://launchpad.net/~yade-dev Post to : yade-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
Re: [Yade-dev] [Bug 850864] Re: strange facet-sphere behaviour
Well, basically, it is not possible to fix this problem with the current logic, where each facet is an independant body. We need to consider a triangulated surface as one entity and define contacts differently if they are on facets, edges, or vertices. In order to do that, we need a well designed data structure defining the connectivity of facets, and used by Ig functors to track the contacts passing from one facet to the other. The problem is similar as in chained cylinder, but in 2D (while chained cylinders are 1D). It would be a big step, but it is not a small job. Bruno On 11/04/12 13:08, Klaus Thoeni wrote: > Hi Bruno, I might have found a student which can work on it. What do you > think? Is it tricky? I didn't have a look at it since last time we > talked about it and it seams the bug is still existing. Let me know. > -- ___ Bruno Chareyre Associate Professor ENSE³ - Grenoble INP 11, rue des Mathématiques BP 46 38402 St Martin d'Hères, France Tél : +33 4 56 52 86 21 Fax : +33 4 76 82 70 43 ___ Mailing list: https://launchpad.net/~yade-dev Post to : yade-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
Re: [Yade-dev] [Bug 850864] Re: strange facet-sphere behaviour
Ok, this job might be too big for the studend indeed. On Wed, 11 Apr 2012 11:45:52 PM Bruno Chareyre wrote: > Well, basically, it is not possible to fix this problem with the current > logic, where each facet is an independant body. > We need to consider a triangulated surface as one entity and define > contacts differently if they are on facets, edges, or vertices. > In order to do that, we need a well designed data structure defining the > connectivity of facets, and used by Ig functors to track the contacts > passing from one facet to the other. > > The problem is similar as in chained cylinder, but in 2D (while chained > cylinders are 1D). It would be a big step, but it is not a small job. > > Bruno > > On 11/04/12 13:08, Klaus Thoeni wrote: > > Hi Bruno, I might have found a student which can work on it. What do you > > think? Is it tricky? I didn't have a look at it since last time we > > talked about it and it seams the bug is still existing. Let me know. ___ Mailing list: https://launchpad.net/~yade-dev Post to : yade-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
Re: [Yade-dev] [Bug 850864] Re: strange facet-sphere behaviour
Hi Anton, some time ago I had a quick look into that problem as well. Actually I mentioned the problem to Dion from ESyS-Particle and he told me that they are solving this problem by distinguishing contacts with vertices, edges and facets. I think the sequence of checking is important too. You are familiar with ESys, aren't you? You could ask Dion where exactly the code for this problem is. HTH and thanks for looking at this problem! Klaus On Tue, 18 Sep 2012 03:41:08 AM you wrote: > Dear developers, > > I was trying to fix the bug, but I have got a problem, which I cannot solve > for the moment. As you know, problem appears, when the sphere touches > (penetrates) on the edge of 2 or more facets and gets from all of them the > forces. Which is not quite correct. > > I was trying to implement the following fix. Facets are united in "chains". > The chain consists of the facets, which are in the common case building a > "surface". So the sphere can interact at the same time only with 1 facet > of the chain. All other interactions of the sphere with other elements of > the same chain are switching off. > > The fix is working relatively good for quasi-static tasks. But when a > sphere rolls over the surface, it "falls" down after the first facet. > Because on the edge it should take an additional force from the "next" > facet, which is not happens. That is what we tried to avoid. > > I hope you understood, what I mean. If not, let me know, I will try to > explain by other words. It would be interesting to check other DEM-codes, > how this problem is solved there (if it is solved). Also comments and > suggestions are welcome. > > Thank you. > > Anton -- You received this bug notification because you are a member of Yade developers, which is subscribed to Yade. https://bugs.launchpad.net/bugs/850864 Title: strange facet-sphere behaviour Status in Yet Another Dynamic Engine: Confirmed Bug description: See https://answers.launchpad.net/yade/+question/171223 Spheres that are exactly on an edge between facets behave strangely. Maybe related to other (closed, but never solved) bugs in sphere- facet. To manage notifications about this bug go to: https://bugs.launchpad.net/yade/+bug/850864/+subscriptions ___ Mailing list: https://launchpad.net/~yade-dev Post to : yade-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
Re: [Yade-dev] [Bug 850864] Re: strange facet-sphere behaviour
Hello Eugen, I have a plan to implement it in a few months time (summer or autumn, most likely not spring). Would it be ok for you, or do you need something earlier? If my plan changed, I will inform you :-) cheers Jan 2013/3/27 Eugen Kubowsky <850...@bugs.launchpad.net> > is there any plan when this new net of classes will be implemented? > > -- > You received this bug notification because you are a member of Yade > developers, which is subscribed to Yade. > https://bugs.launchpad.net/bugs/850864 > > Title: > strange facet-sphere behaviour > > Status in Yet Another Dynamic Engine: > Won't Fix > > Bug description: > See https://answers.launchpad.net/yade/+question/171223 > > Spheres that are exactly on an edge between facets behave strangely. > Maybe related to other (closed, but never solved) bugs in sphere- > facet. > > To manage notifications about this bug go to: > https://bugs.launchpad.net/yade/+bug/850864/+subscriptions > > ___ > Mailing list: https://launchpad.net/~yade-dev > Post to : yade-dev@lists.launchpad.net > Unsubscribe : https://launchpad.net/~yade-dev > More help : https://help.launchpad.net/ListHelp > -- You received this bug notification because you are a member of Yade developers, which is subscribed to Yade. https://bugs.launchpad.net/bugs/850864 Title: strange facet-sphere behaviour Status in Yet Another Dynamic Engine: Won't Fix Bug description: See https://answers.launchpad.net/yade/+question/171223 Spheres that are exactly on an edge between facets behave strangely. Maybe related to other (closed, but never solved) bugs in sphere- facet. To manage notifications about this bug go to: https://bugs.launchpad.net/yade/+bug/850864/+subscriptions ___ Mailing list: https://launchpad.net/~yade-dev Post to : yade-dev@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-dev More help : https://help.launchpad.net/ListHelp
