Hi, Dear All, I readed the code in PersistentSAPCollider, but I am sad because I found I can not understand how the program works to find the potential contacts? could you please give me some hints about the details of the detectalgorithm? It seems a position of a particle is decomposed to xBounds, yBounds, zBounds, then sort it, then compare the x,y,z in these three xBounds, yBounds, zBounds vectors? but how does it work? I still cannot understand.
Thanks a lot. Kan. On 2/14/08, [EMAIL PROTECTED] < [EMAIL PROTECTED]> wrote: > > Send Yade-users mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.berlios.de/mailman/listinfo/yade-users > or, via email, send a message with subject or body 'help' to > [EMAIL PROTECTED] > > You can reach the person managing the list at > [EMAIL PROTECTED] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Yade-users digest..." > > > Today's Topics: > > 1. Re: What is the contact detecting method used in YADE? > (Kien Dang, Mr) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 13 Feb 2008 14:58:03 -0500 > From: "Kien Dang, Mr" <[EMAIL PROTECTED]> > Subject: Re: [Yade-users] What is the contact detecting method used in > YADE? > To: <[email protected]> > Message-ID: > < > [EMAIL PROTECTED]> > Content-Type: text/plain; charset="iso-8859-1" > > > Hi, > > you can look at the engine persistentSAPcollider, this engine update the > pair of potential contact by sorting bubble bounding volume method, and then > check if the bounding volumes are overlap or not, if yes, the pair of IDs is > assigned to the interactioncontainer (transientInteraction in Metabody). > Note that they are only potential contacts since only the bounding volumes > are checks, and then, pairs of particles are checks again in > InteractionGeometryMetaEngine to determine if they are really in contact or > not. If they are really in contact, flag isReal in interaction is true and > then the contact geometry is built for each real contact. > > Hope that I can understand your question clearly, > > Take care, > > Kien Dang > -----Original Message----- > From: [EMAIL PROTECTED] on behalf of kan > Sent: Wed 2/13/2008 2:56 AM > To: [email protected] > Subject: [Yade-users] What is the contact detecting method used in YADE? > > Hi, Dear All, > > I am just losting myself in understanding the contact detecting method in > a > DEM. > could you please give me some instruction or explaination about what is > the > contact detecting method used in YADE? > It is easy to detect if two contacted particles becomes non-contacted > again > by check the distance between their center with their radius > sum(radius1+radius2, assume both of them are sphere) because they know > each > other when they are in contact an have stored their neighbors relationship > for each other. But, how do you know whether two will change from > non-contacted conditions to contancted condition----because they do not > know > each other before then come to contact, do not tell me that you check each > pair in all of the particle---it works but the time cost is toooooo > expensive . > > Thanks. > Regards. > > Kan > > > > ------------------------------ > > _______________________________________________ > Yade-users mailing list > [email protected] > https://lists.berlios.de/mailman/listinfo/yade-users > > > End of Yade-users Digest, Vol 20, Issue 10 > ****************************************** >
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