STL File Displays Fine, VRML File Is Strange

Discussion in 'Bug Reporting' started by dragonsdesire, Mar 10, 2013.

  1. dragonsdesire
    dragonsdesire New Member
    Hi there! I decided to color my model and save it as a VRML file. The problem is that even though it came from the same file that I'm working on (only difference is I saved it as a VRML file with color), when displayed on Shapeways my model is standing on its head.

    [​IMG]

    What could be the problem here?

    Program Used:
    Zbrush -> used 3D Print Exporter plug-in to make the STL and VRML file. STL displays as it should, VRML becomes weird.

    Thanks in advance :)
     
  2. dragonsdesire
    dragonsdesire New Member
    I tried it again just now. I uploaded both an STL and VRML file (.WRL) and the STL displays properly while the WRL makes my model stand on its head. Hmm, thanks in advance whoever could give an advice or tip so that the VRML file would display properly (I'm using the Z is up, model must face -Y environment). :)
     
  3. stop4stuff
    stop4stuff Well-Known Member
    Not knowing the software, I'm guessing that at some point during the stl->vrml process the axis for the model has changed.

    Paul
     
  4. dragonsdesire
    dragonsdesire New Member
    Hi again! I just recreated the process and it's still happening for some odd reason.

    This shows that the model is following the "Z is Up, Must Face -Y" orientation:

    [​IMG]


    This one shows the VRML settings I used:

    [​IMG]


    I uploaded the VRML and the STL models just to see what would happen. I also made an extra VRML where I rotated model in such a way that the Shapeways auto-preview generator would show it "correctly" and not standing on its head. You'll notice that the STL model (middle, uncolored) faces properly. The first VRML file I uploaded (the one on the very right) is standing on its head. The last VRML I uploaded (the one I rotated) is now facing correctly, but notice the sudden change in price!

    [​IMG]


    To investigate, I checked the dimensions shown on the page of my first VRML and the STL models. They show the correct dimensions.

    [​IMG]


    Then I checked the dimensions on the second VRML model (the one I rotated). I didn't change the measurements in Zbrush. I simply rotated this one and exported it as VRML, but look at how the size suddenly increased.

    [​IMG]



    Very strange indeed! Anyway, I wonder if ever somebody decides to print out the first VRML (the one standing on its head) it would print out just fine? I still wonder why only VRML files are affected while the STL file just displays fine following the Z-up orientation. Hmmm... :)

     
  5. Youknowwho4eva
    Youknowwho4eva Shapeways Employee Community Team
    Go to edit mode on your models. Scroll down to the bottom and there will be a green bar that has the file name of your item. I'm betting one of them (probably the one standing on it's head) says "rescaled during upload to current size"
     
    Last edited: Mar 11, 2013
  6. dragonsdesire
    dragonsdesire New Member
    Hi thanks for answering!

    I checked all the models I uploaded in the Edit Model section and I found the File Status at the bottom of the page. None of them said anything about rescaling the model I uploaded. I even checked the model that I rotated just to make it look right on the screen and its file status had nothing about being rescaled.

    Such a mystery! I'm sending both STL and VRML files to service @ shapeways right now, maybe someone there could look into why this is happening and what's the possible solution. :)
     
  7. dragonsdesire
    dragonsdesire New Member
    First of all, I'm glad to know that someone from Shapeways received the files and my e-mail (I received their reply today from Ms. Tuijl) and they're checking out what's going on.

    Anyway I went on ahead and did another experiment today. I used to make models following the "Z is Up, -Y is Front" orientation that most guides suggest would work best with 3D printers. I know this works for STL files because when I uploaded STL files using this orientation, there were no problems as you can see in the above pictures and only VRML is affected.

    A few minutes ago I decided to make a test character using the "Y is Up, Z is Front" orientation (this is the default Zbrush orientation). I made both VRML and STL files and here are the results.


    VRML shows it correctly as I modeled it in Zbrush in the kneeling position:
    [​IMG]




    STL shows it wrong and rotated my model into a lying position:
    [​IMG]



    From this experiment, what I found out seems to be:

    1. "Z is Up, -Y is Front" orientation only works properly in the previews for STL files.
    2. "Z is Up, -Y is Front" orientation will rotate my VRML file in the previews.
    3. "Y is Up, Z is Front" orientation only works properly for VRML files.
    4. "Y is Up, Z is Front" orientation will rotate my STL file in the previews.

    First Possibility:
    My problem must be caused by something in the way Zbrush's 3D Print Exporter makes the STL and/or the VRML files.

    Second Possibility:
    The files created by Zbrush's 3D Print Exporter could be fine but there is something in the way Shapeways reads the VRML files that makes the model rotate.

    Anyway, I wonder if the orientation for VRML files for Shapeways is supposed to really be "Y is Up, Z is Front" and I just didn't know about it. Maybe this is an isolated case and I'm the only one affected.

    Are there any other Zbrush users out there who can try out to see if their STL and VRML files get displayed differently after uploading to Shapeways?

    Thanks in advance:)
     
  8. stannum
    stannum Well-Known Member
    The "axis dance" is general. Everyone has to figure how it works with their software and formats, and rotate accordingly. The request to be able to get a rerender with a different orientation is pretty old, in the meanwhile all you can do is accept the preview is weird or reupload so it shows as you want.
     
  9. dragonsdesire
    dragonsdesire New Member
    Ah, so as long as it shows "correctly" in the previews, there should be no problem? Alright, for now I'll use the "Y is Up, Z is Front" orientation when making colored models.

    People can still order single colored versions of a model even if all I uploaded was a VRML file right ? For example, that weird monster I made can still come out as all white and all black as long as people don't buy the Full Colored Sandstone version right?

    Thanks for sharing your thoughts and experience on the matter :)
     
  10. stannum
    stannum Well-Known Member
    Preview orientation is not used for printing orientation, if that is what you were supposing. What is more, you are not guaranteed that print will not be rotated in non 90 steps, as some people can testify after receiving big flat zones with stepping (model rotated 2 or 3 or X degress).

    And yes, if people order in a different material (and it passes all the hurdles for it), they will receive a non-multi-color print of the VRML, just the basic color the material they pick. The other way around too, they can order a non colored (STL) model in Sandstone (of course, it will be raw color, offwhite) if what the want is the surface finish it has.
     
  11. dragonsdesire
    dragonsdesire New Member
    Thanks for answering my questions! I'm more at ease now and I can go back to making more of my beloved creatures (which hopefully people would buy) :)