Only back faces display?

Discussion in 'Software and Applications' started by 25882_deleted, Aug 11, 2009.

  1. 25882_deleted
    25882_deleted Member
    Here's the model in question.

    I uploaded an .stl from Blender and it processed and scaled correctly, was accepted as printable, but both the thumbnail and 3D preview only seem to show the backfaces of the object from any given angle. Has anybody encountered this problem before, and does it mean there is a problem with the model itself that can be fixed? Thanks,

    -Philip
     
  2. 21170_deleted
    21170_deleted Member
    Hi Phil;

    What you are seeing there is an inside out object. hehe. Most likely the issue is that the Normals are all pointed to the inside instead of the outside. (I had the very same issue once.) Easy fix in Blender is to go into edit mode. and select all the verts, then hit {CTRL+N} to recalculate the normals to face outwards.

     
  3. 25882_deleted
    25882_deleted Member
    Okay, I just tried that, but now I just get an email saying it wasn't printable because "Your model has inverted normals in it." Which is sort of what I expected given that I wasn't getting a normals error before. Any thoughts?
     
  4. 21170_deleted
    21170_deleted Member
    Hmmmm....


    Sounds like Blender is having problems deciphering inside from outside. Try removing doubled verticies.
    If that doesn;t work, PM the .Blend to me and I take a look.
     
  5. Youknowwho4eva
    Youknowwho4eva Well-Known Member
    I have had models do this in the software I use. Usually I do a heal and it works. If you software doesn't offer a heal try copying the model into a new drawing and saving the new drawing, or exporting and re import back into the software. Both should cause an automatic solids heal. But seeing the image problem is on shapeways side I would think it would be their software having the issue, but you want it to be right so people can see it properly.
     
  6. 25882_deleted
    25882_deleted Member
    Well I tried a few different things and have got it working now, I think removing doubles might have been the thing that fixed it but I can't be sure since I did some other little adjustments all at once. Thanks guys.
     
  7. 21170_deleted
    21170_deleted Member
    Groovy man!

    Good job!