Dear Bruno, Thank you for forwarding, that sounds like a very interesting and useful project!
I have been chatting to Vasileios about this as well, but I'm working on a generalised package for making level set particles / objects and hope to finish it in a month or two. I have also had some success in scanning in some powders with microCT to get particle shapes. - The importing of level-set particles into YADE is currently something that I don't have a proper file format for; I just write things to a .csv file and load that using YADE's python interface. I will publish my script for this together with the package I am building. - Generating level-set particles from microCT is not a trivial task. If they want to supply these in their database, I recommend they wait until I have published the package (open source) and use that code. - For the package, I can deal with a lot of different input data already, as long as the individual particles are clearly labelled. Given the starting data is from microCT, the easiest input data is a single file per particle containing the binary voxel image of that particle. (The same applies to Vasileios' CLUMP library, I think.) Clumps, triangular meshes, and potential particles can all be converted to level sets. Converting an improper mesh to a level-set object will automatically close the mesh in an intuitive way. - I think Vasileios' CLUMP library also has a way to make meshed/polyhedral particles from images. Not sure if it works for concave particles, but an easy way to do this (maybe with a bit of overkill on the resolution) is to binarise the image and then apply marching cubes. Are the people from Sand Atlas already involved with the ON-DEM project ( https://www.cost.eu/actions/CA22132/) ? With kind regards, Danny Op di 30 jul 2024 om 14:20 schreef Bruno Chareyre < bruno.chare...@3sr-grenoble.fr>: > > Dear Yade devs, > > Benjy Marks/Sydney is providing grain shape data from CT on Sand Atlas > website > <https://url.au.m.mimecastprotect.com/s/yQb_C5QPXJiglW59xIzXERg?domain=sand-atlas.scigem.com/> > and he is interested in making that data compatible with direct imports in > shape models. It seems to me in requires a bit of work on either Yade or > Sand Atlas sides, or both. > > IIRC Vasileios developed a tool to convert images into shape models > already, Jérôme/Dany may have ideas for the case of level sets too. Others? > > 1/ Which would be the most basic and generic data format for raw data? > (presumably voxel data) > 2/ Which are the *available* functionalities to convert raw data into a > DEM shape model? > 3/ Which are the *unavailable* functionalities needed to convert raw data > into a DEM shape model? > > Cheers > > Bruno > > > > -------- Forwarded Message -------- > Subject: Re: The Sand Atlas > Date: Wed, 24 Jul 2024 18:54:53 +0000 > From: Benjy Marks <benjy.ma...@sydney.edu.au> <benjy.ma...@sydney.edu.au> > To: Bruno Chareyre <bruno.chare...@3sr-grenoble.fr> > <bruno.chare...@3sr-grenoble.fr>, bruno.chare...@univ-grenoble-alpes.fr > <bruno.chare...@univ-grenoble-alpes.fr> > <bruno.chare...@univ-grenoble-alpes.fr> > CC: Ilija Vego <ilija.v...@sydney.edu.au> <ilija.v...@sydney.edu.au> > > Hi Bruno, > > Essentially we have the 3D data from CT scans of the particles and we are > willing to convert them into whatever shape models yade developers would > prefer. I'm impressed that yade accepts 5 different shape models! We can > certainly produce 5 different file types and have them all available if the > yade team thinks that will be useful. The main point for us is to make all > of this existing data available and useful for as many people as possible. > > Benjy > > ------------------------------ > *From:* Bruno Chareyre <bruno.chare...@3sr-grenoble.fr> > <bruno.chare...@3sr-grenoble.fr> > *Sent:* Thursday, July 25, 2024 1:10:28 AM > *To:* Benjy Marks <benjy.ma...@sydney.edu.au> <benjy.ma...@sydney.edu.au>; > bruno.chare...@univ-grenoble-alpes.fr > <bruno.chare...@univ-grenoble-alpes.fr> > <bruno.chare...@univ-grenoble-alpes.fr> > *Cc:* Ilija Vego <ilija.v...@sydney.edu.au> <ilija.v...@sydney.edu.au> > *Subject:* Re: The Sand Atlas > > > Dear Benjy, > > > Thank you for the suggestion, it sounds interesting. It seems it all > depends on which shape model would be used: > > - multisphere approximation > - raw polyhedron > - Minkowski polyhedron > > - potential particle > > - level set > > - (other things I can't imagine and which aren't implemented in Yade > a.t.m.) > > > That's five different "download for" already. :) > Do I miss something? > > > I'm not the most active in shape models actually. I should probably > forward your proposition to other devs, or directly to yade mailing list. > > But before that could you clarify what sort of data you would provide / > how close to shape models it would be? > > Kind Regards > > > Bruno > > > > On 23/07/2024 00:51, Benjy Marks wrote: > > Hi Bruno, > > How are you? I hope you're well. > > We are putting together an open source repository called the Sand Atlas > <https://url.au.m.mimecastprotect.com/s/yQb_C5QPXJiglW59xIzXERg?domain=sand-atlas.scigem.com/>. > It is a website for hosting 3d models of particles, so that they can be > used in DEM codes etc. I was wondering if this would be useful for YADE? If > so, I would like to make it just a single click on our website where users > can click "Download for YADE" and it gives them correctly formatted files > so that they can be used seamlessly. We will try to do the same for other > open source DEM codes too. > > The website now is more of a tech demo, many of the links dont work and > the particles arent meshed that nicely, but this will all hopefully be > sorted out in the next month. We also have asked around to a bunch of > researchers and hope to have 50+ particle types available by September. > > If you have any feedback about the website, or ways that this kind of data > might be useful to you or others, please let me know! > > thanks, > benjy > > -- > > *Bruno Chareyre* > > *Associate Professor * > > > > > > *Grenoble INP - UGA Institut d'ingénierie et de management / Graduate > Schools of engineering and management 46 av. Félix-Viallet - 38301 Grenoble > www.grenoble-inp.fr > <https://url.au.m.mimecastprotect.com/s/mUDIC6XQ4LfVWGjm1u6CDu6?domain=grenoble-inp.fr> > * > > > > > > *3SR Lab Soils, Solids, Structures, Risks 1270, rue de la piscine - 38400 > Saint Martin d’Hères www.3sr.univ-grenoble-alpes.fr > <https://url.au.m.mimecastprotect.com/s/i5P-C71R2NTERW4NQuBAaiU?domain=3sr.univ-grenoble-alpes.fr> > * > _______________________________________________ > 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 >
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