newb to everything 3d

Discussion in 'General Discussion' started by bronkorob, Jul 2, 2013.

  1. bronkorob
    bronkorob New Member
    I am starting to get frustrated with this. I am trying to make my first little part and trying to convert to STL and make sure there are no issues, since my first few uploads have been kicked back. I have followed the directions in the tutorials about using meshalb ad netfabb, and I am still getting all kinds of errors. I did manage to successfully upload something to my account, but it was only 33% of the original part.

    i exported from sketchup the model as a WRL file, than used meshlab to convert to STL, than open with netfabb to do repairs.

    can someone explain to me what netfabb means by invalid orientation? I start with many holes, a few shells and some invalid orientations, than i do the repairs, end up with more shells, no holes and still a ton of invalid orientation issues. the repair also pulled a lot off my original model as well. it seems to be looking worse the more it is repaired.

    I originally made the model using sketchup, if that has anything to do with it.

    any advice or tips would be greatly appreciated.

    also included my original sketchup file if anyone can take a look and see if there is anything obvious.
     

    Attached Files:

  2. JACANT
    JACANT Well-Known Member
    Nothing the matter with this file.
    When you export as Stl from sketchup, open the file in Netfabb to check it's size.
    When I opened it your model was only 4.43 x 0.13 x 1.01 mm. I scaled by 25.4 to get 112.41 x 8 x 25.66 mm

    Invalid orientations also known as inverted normals are faces not pointing the correct way, i.e. when faces are inside out.
    A normal is http://tinyurl.com/8hv52hl
    A surface is made up of many triangles (faces) especially on curves. The smoother the curve the more triangles and faces it will have.

    The reasons you get this in Sketchup is that if you draw any extra lines on a surface a new face will be created. Then you have faces on top of faces and Shapeways software does not know which is inside and which is out. It tries to repair the faces by deleting what it thinks are the inside facing surfaces. It does not always get it right and may delete the wrong face. That is why you may have parts missing.

    Delete all extra lines including 'guide lines', you can see these by showing hidden geometry. If you delete the wrong line and the face disappears just redraw that line. Try to make each part as a component, then use the outer shell command to join them together. If the parts are overlapping each other this will intersect the surfaces and delete all of the internal lines and faces not required. So you end up with one shell with all of the surfaces pointing out in the right direction.
     

    Attached Files:

  3. bronkorob
    bronkorob New Member
    JACANT - you are my hero! i never even thought to look at the scale. I am glad it was relatively simple, makes me feel better about my abilities. live and learn. thanks again.