Chainmaille

Discussion in 'Design and Modeling' started by stop4stuff, Feb 26, 2017.

  1. stop4stuff
    stop4stuff Well-Known Member
    Hiya,

    I suppose i should know being a 'well known member', trouble is, i'm recovering from some issues and can't remember alot of nitty gritty stuff...

    my Qs today are...

    1. How many faces/polys does shapeways accept at upload?
    2. Is there still a problem of time out if there are too many interlocking parts?
    3. shall i just try to find out anyway?

    cheers,
    Paul
     
  2. stonysmith
    stonysmith Well-Known Member Moderator
    1) RUMOR has it that the official number is still 1m TRIANGLES, but the system may allow some overages. Note: quads, hexagons, polygons must first be triangluated. 1m quads would be 2m triangles.
    2) Yes. The difficulty is quantifying how many too many" is. (it can also be affected by how busy the servers are)
    3) Yep. Your mileage may vary.
     
  3. mkroeker
    mkroeker Well-Known Member
    1. Still 1 million triangles officially (some have claimed to have successfully uploaded around 2m)
    2. Never had models with more than 2 shells due to the nature of my work, but timeouts occur occasionally (probably sometimes caused by the sheer number of checks now that there are so many materials, with no way to exclude the irrelevant ones)
    3. Probably best
    4. Good to see you back
     
  4. stop4stuff
    stop4stuff Well-Known Member
    Stony - thanks, about the same as i remember then... shit it must have been a dream.
    mkroeker 4, :) thank you
    and 2) is to do with interlocking shells and the model integrity - the number of faces per shell, the amount of interlocking shells and the overall number of shells vs polys (triangles) seems to cause some bolloxation and cause a timeout even before any material checking goes on...
    i've also spotted some other stuff s/w changed... email headed soon to put it right :)
     
  5. stonysmith
    stonysmith Well-Known Member Moderator
  6. stop4stuff
    stop4stuff Well-Known Member
    looks like a variation of a japanese 4 in 1 - that ain't gonna cause bolloxation - i'm talking a lot of interconnecting pieces such as - http://shpws.me/DpV2 - iirc this only has sub 500k faces but with 1800+ shells, SW's software was on the verge of a time-out (2000 was too many) for integrity checking - more interlocking parts = more threads = slower speed = more likely for a timeout... but that was 5 years ago... has anything much changed?
     
  7. Andrewsimonthomas
    Andrewsimonthomas Well-Known Member
    @stop4stuff we're regularly making improvements but timeout can also be a factor of other issues, I'd say its worth trying again
     
  8. stop4stuff
    stop4stuff Well-Known Member
    Hi Andrew :)

    Basically, I'm making some chainmaille garments for 1/4 scale.
    I don't need to spend too much time faffing about figuring out the optimum number of shells vs triangles per shell, coz i already did that... an idea of MeshMedic's timeout would be good... once upon-a-time it was 10 minutes - and then got extended to 20... Then in the fuzziness somewhere, my head says i got bumped back to 10... but that was a few years ago.

    If you ain't seen any changes, or even tell me of any, then I may as well carry on and slow down the system for everyone...

    >:)
    paul

    p.s. to every one else.

    Sorry.

    My activity over the next day or so might cause some hiccups.
     
  9. MrNibbles
    MrNibbles Well-Known Member
    On a somewhat related note does the 64MB file upload size limit refer to a raw file or a compressed file? In other words is the hard limit the 1,000,000 triangles or the file size or both?
     
  10. MrNibbles
    MrNibbles Well-Known Member
    Just for giggles and grins I uploaded a 62.5MB chainmaille file with ~1.28 million triangles. The preview shows a highly faceted version of the model, although when I download the model again from Shapeways and compare it to the originally uploaded file it appears to be the same. Here is the 3D tools link:
    https://www.shapeways.com/model/3dtools/5778122/0/6?key=92048254fdeacc7369da07554c134fc8

    uploaded chainmaille.jpg

    I uploaded another version of the file having just under 1 million triangles and it looks just fine after it is uploaded.

    So what is happening here? If a file is uploaded with >1 million triangles does it get remeshed to have fewer triangles for production purposes? Or is the highly faceted preview in 3D tools just an artifact of the processing required because chainmaille has so many shells? What is real and what would the print look like? Smooth or faceted?
     
  11. stonysmith
    stonysmith Well-Known Member Moderator
    The upload limit is a function of the website code that does the upload. You can upload a 64mb ZIP file, which could be much larger inside.

    Neither and both. The previews (and all the 3dtools) are voxelized presentations. Your model is converted to voxels (little tiny cubes), and then a decimation (polygon reduction) algorithm is applied to the resulting mesh to reduce the total number of triangles required to display the model. It's that (reduced) version which is presented to you for review in the browser, but it's not "real".

    When you download the model, you only get back your original model. But.. your ORIGINAL mesh is sent to the printer.

    To be hyper-technical, the printer itself also does it's own form of a voxelization, based upon the diameter of the nylon powder granules and the width of the laser beam. But.. the printer doesn't apply a decimation algorithm, other than simply the effect of physics and the resolution of the printer.

    Power tip: Even if your model has no serious errors, run the ThinWallsFix, and save the result. When you download THAT model, it'll be the voxelated/decimated model. The statement is that the voxelization is done at a level below the resolution of the printer, so it SHOULD not affect the final print.
     
  12. MrNibbles
    MrNibbles Well-Known Member
    I see. So what must be happening is that the voxelization routines are dependent on something like overall physical file size and probably less so for things like facets or shells or file memory size.

    Here is the exact same chainmaille file mentioned above but with enough loops removed to get below the 1 million triangle limit. This one sits at around 980k triangles. But the loops and meshing for each individual loop are exactly the same - there are just fewer of them and the overall size of the entire model is slightly smaller. It would make sense that the 3D tool images will look better with smaller voxels, assuming that's what's happening here.

    https://www.shapeways.com/model/3dtools/5777987/0/6?key=9b627486ced0dceade9b006446d48f63

    uploaded chainmaille 2.jpg
     
    shawn_halayka likes this.
  13. stop4stuff
    stop4stuff Well-Known Member
    lol... you've both been chatting about the same as I've been doing...

    good news...

    4k+ rings with 1.04m triangles uploads just fine, filesize binary stl is around 50MB

    'cept mine have an AR of 4.0 :)

    Paul
     
  14. stop4stuff
    stop4stuff Well-Known Member
  15. MrNibbles
    MrNibbles Well-Known Member
    That's a lot of rings. I noticed that the new 3D viewer is not available if the model is public but not for sale so it's hard to see any detail at all!
     
  16. stop4stuff
    stop4stuff Well-Known Member
    Yep, the number is falling as I trim rings away to shape the garment.
    And the rings are pretty small, 4.8mm OD - mabye that's got something to do with lack of detail?
     
  17. MrNibbles
    MrNibbles Well-Known Member
    My test case used 9.2 mm OD rings but I only had 800 total rings. My monitor must be too old because your design with so many more loops looks like a solid sheet of slightly porous material! :)
     
  18. stop4stuff
    stop4stuff Well-Known Member
  19. MrNibbles
    MrNibbles Well-Known Member
    If you put enough strands of hair in that it might make a nice hair piece for the follicularly challenged!
     
  20. stop4stuff
    stop4stuff Well-Known Member
    erm... it wouldn't fit on my head, let alone yours... the whole garment is only 10 x 28 cm ;)