Colour per vertex in VRML?

Discussion in 'General Discussion' started by Mat Cook, Jan 23, 2012.

  1. Mat Cook
    Mat Cook New Member
    Hi folks,

    I have several models that I will be printing using your 3d colour service. The models are people, about 30cm tall, and are coloured to act as a visual aid to understanding our graphics technology.

    Your FAQ suggests colouring per face in VRML, and this isn't ideal for our application. Unwrapping it into a texture isn't easy either. So I am wondering if your VRML importer understands per-vertex colouring? Can I specify the colour per vertex and have this interpolated across each face by your software?

  2. aeron203
    aeron203 New Member
    Per-vertex coloring will work, but don't be suprised if it gets converted to per-face color on output. This isn't Shapeways fault, it's the printer software doing it. I'd suggest sub-dividing your model to help preserve color boundaries.

  3. Mat Cook
    Mat Cook New Member
    Thanks for the quick response!

    For one of the models we're doing, we want a smooth graduation of colour across each face (a little bit like your rainbow samples). From what you're saying I should subdivide the mesh more and do per-face colouring.

    Do you know the "pixels per inch" for the colouring... ie how small can/should the faces be? (just roughly)
  4. aeron203
    aeron203 New Member
    The dpi of the printer is 600x540, but it does not reach anywhere near that kind of detail in practice. The layers are about a tenth of a millimeter thick, so faces much smaller than that would not be useful. Most software is not very disciplined with the face/vertex color distinction so plan on this being fudged at some point. Keep them small and you will be ok.

  5. Mat Cook
    Mat Cook New Member
    So I converted my model to per-face colouring, splitting the triangles along colour boundaries, and I have to say the resulting model you guys just shipped is fantastic!

    We're all super pleased with it here and will be ordering lots more from you in the next week or two.

    One quick question before my next round of printing: does your software honour or ignore the creaseangle supplied in the VRML? Does it smooth and curve the facets, or is it printing them out as they are specifid?

    Thanks again..