Why does this look so bad?

Discussion in 'Design and Modeling' started by Malcr001, Apr 9, 2012.

  1. Malcr001
    Malcr001 New Member
    I'm new to shapeways so I was hoping someone can help. Ive uploaded the 3D as an .obj file and this is the result I get:

    http://www.shapeways.com/model/534020/455b2938ad481032e4563f d7b29bce94

    My question is why does this look so bad. Its not smooth at all. Under blender and maya its nice and smooth.

    I recently read a thread about how 3D printers cannot read any smooth modifiers and so you need to convert everything to polys. That is what has been done, is it a matter of smoothing it out even more??

    I think its to do with the dimensions. There not showing up right at all. The diamter of the dome should be 16.2cm
    Last edited: Apr 9, 2012
  2. damocles
    damocles New Member
    That last bit, 6.4 inches is 16.3 cm, 6.4 mm is 0.64 cm. When you upload, there's a drop-down to select units since the common file types are unitless. You probably selected mm, but needed inches based on how you exported it.

    Depending on how you export it, there are a number of ways in which the quality of the mesh could vary. Increasing the polygon count and reducing the error tolerance can help...different programs have different ways of representing this. However, if you set it too high, you'll go over the 64MB upload limit. Something like 100k to 200k polygons is ample for most models.
  3. Malcr001
    Malcr001 New Member
    Thanks for the reply. Yep its because I set it to millimeters instead of inches. I've noticed on large items white strong and flexible polished isnt available? But when the model was set using millimeters the option was available. Does this mean theres a size limit to the models they can polish?

    I have tried to increase the polys as much as possible. Unfortunatly the model shot up from 20mb to about 300mb simply by adding another division although I think it should be ok.

    Because the WSF polished option wasent available I just selected white strong & flexible. Does this mean my models going to be sent to me with a rough texture?
    Last edited: Apr 10, 2012
  4. damocles
    damocles New Member
    There's more info on the WSF polishing process here:


    The tumbler will only fit 15x15x15cm, while the printer will do 65x35x55cm.

    WSF isn't all that rough, although it depends a bit on the local geometry. There's a somewhat textured feel to it. I'd see how it turns out, then hand-finish if necessary.
  5. Malcr001
    Malcr001 New Member
    15cm means my models 1.2cm too big. Thats a bummer seeing as my model cannot be scaled down as its designed to be mounted onto a base plate.
  6. stop4stuff
    stop4stuff Well-Known Member
    Rotate the model with relation to the axis before uploading so it fits the bounding box ;)

    [edit]And while you're at it, make sure you save the file as stl binary and if it is still too big, zip it up - its an upload limit, not a model file size limit :cool:

    Last edited: Apr 10, 2012
  7. Malcr001
    Malcr001 New Member
    Unfortunatly the width length were both 16.2cm and the height was 8cm seeing as its a dome.

    I tried all sorts of methods in terms of exporting and the I did just that which was export an stl file and zip it up. Zipping it crunched it down to a about 30% of its origonal size however safeways computers couldent handle the file size of the unzipped stl file and reported a problem.

    I ended up using a model with less polys hopefully its not visible when its printed.
  8. stop4stuff
    stop4stuff Well-Known Member
    Rotating a 16.2 diameter x 8.1 cm (8.1cm height as I don't have the inclination to do any more than a simple hemisphere) dome by 45 degrees on two axes comes in at 15.059586 x 15.059586 x 13.827576 cm, maybe make it 50 degrees and it'll fit

    As for polys, 0.1mm sided faces are spot on for most materials, for FUD go for 0.05mm. Are you sure you didn't hit the 1 million triangle limit? 1M triangles = 500k 4 sided polys. binary stl* with 1 million triangles, zipped up should come in somewhere between 25 & 45MB.

    *There are two kinds of stl, ASCII and binary. Binary stl files come in at around 1/3 the size of ASCII stl files.

    [edit] I just got the same dome in under (just) the 15cm box - 14.785797 x 14.359528 x 14.849655 to be precise

    Last edited: Apr 10, 2012
  9. Malcr001
    Malcr001 New Member
  10. stop4stuff
    stop4stuff Well-Known Member
    That 'domed cylinder' won't fit in a month of Sundays, hey ho... a 15cm square will fit in a 21 cm diameter circle, and your model will definately fit through the same 21cm so it may be worth asking Shapeways Customer Services (service@shapeways.com) if they can help you out.

  11. Malcr001
    Malcr001 New Member
    Thanks I emailed shapeways hopefully they will get back to me soon.
  12. Malcr001
    Malcr001 New Member
    They got back to me and basically said its not possible. Obviously the polishing machine automates the process but can ony do this within a certain size. I would like to see people make a request for a polishing machine that can handle a larger models during shapesways live in about 6 hours.
  13. stop4stuff
    stop4stuff Well-Known Member
    Oh well, at least you now have the definitve answer.

    Head over to http://feedback.shapeways.com/ for suggestions & feedback for Shapeways services and website.

  14. Malcr001
    Malcr001 New Member
    Thanks. I posted the suggestion.