#Flipping out normals!
11 messages in this thread
I am having problems with normals facing the wrong direction. It seems that as
I flip the faces, it just alternates back and forth. I select the faces I want
to flip. I flip them and then the ones that were correct are wrong. I have
read 3D Studio Applied and Inside 3D Studio, but cannot seem to determine what
is wrong. Even the books say this is frustrating, but I must be doing
something wrong.
All help, hints suggestions are very welcome.
Thanks,
Dennis
Have you tried using the object/unify command?
Tim;
>> Have you tried using the object/unify command?
Thanks for your reply. The part was an unusual one. I tried this, and it
wasn't able to fix the problem. After reading all the information I could
find, I was able to flip them a few at a time and resolve the problem.
Dennis
>> The part was an unusual one. I tried this, and it wasn't able to fix the
problem. <<
In what program did you create this object?
– Michael J Sheldon "Falcon", msheldon@crl.com
– When we are planning for posterity, we ought to remember that virtue is
not hereditary. Thomas Paine, Common Sense [1776]
Michael;
It was created in a 3D Solids package called Euclid. The part was DXF'ed out
and obviously had problems. Many other parts were able to have their faces
unified without any problems.
Dennis
The reason I ask is that I had problems with solids created in ACAD12 AME.
I found that if I turned off the "unify normals" option when importing the
mesh, the faces would all be correct. Once the unify normals option had been
used, however, it was a lost cause.
– Michael J Sheldon "Falcon", msheldon@crl.com
– When we are planning for posterity, we ought to remember that virtue is
not hereditary. Thomas Paine, Common Sense [1776]
Michael;
>> I found that if I turned off the "unify normals" option when importing
I had found that also. I don't know why, but I too turned that switch off when
using ACAD AME files. It's not a bug, it's a feature!
Thanks for sharing that though. It would have been very helpful if that was
the problem. And maybe it will be for others.
Dennis
Since flipping face normals is a toggle (the IN face becomes the OUT face, and
vice-versa) sounds like you might be selecting a set of both IN and OUT faces
and then, by flipping them, simply getting a set of OUT and IN faces. You need
to flip only the faces whose normals are pointing in the wrong direction. The
Unify command will attempt to do this for you automatically, and works pretty
well for most objects. Also, keep in mind that faces are triangular. You should
probably turn on Display/Geometry/All Lines and Backface mode to help see what
you're dealing with.
If you have a number of jobs with complex meshes and need to do a lot of face
flipping (such as on importing improperly made DXF files) you might consider
getting Disk #7 from the Yost Ipas Boutique. Its Optimize program has a routine
that lets you see the face normals as graphic arrows to help with face
flipping.
– Jack
Jack;
>> You should probably turn on Display/Geometry/All Lines and Backface
>> mode to help see what you're dealing with.
I did finally do this, and found that if I selected a face that was correct, it
would turn red, but one's that were incorrect would not turn red. I was able
to use this to select the proper faces and get the problem resolved.
I also learned a few things about part creation. Avoid radius corners unless
absolutely necessary. There were a lot of triangular faces hiding in the small
radius corners. It wasn't fun to find and fix them.
>> Its Optimize program has a routine that lets you see the face normals
>> as graphic arrows to help with face flipping.
This sounds like a very wonderful program. I was wondering if there was
something like this available.
Thanks,
Dennis
Dennis, If you've got Optimize normal editing is much easier as you can see all
of them and do instant test renders. If you don't you should get it – I think
there's a demo in the libraries.
DM
David;
>> If you've got Optimize normal editing is much easier
Thanks for the tip. I will probably get this. I wanted that one anyway. This
will give me a better reason to get it.
Dennis