#Unifying Normals
7 messages in this thread
I have a fairly complex object that I have imported into 3D Studio
from a DXF (the object was originally created in AutoCAD AME)
Now that it's in, many of the faces are flipped the wrong way, and
the "Object Unify" command does not affect them. I have had success
with portions of it, by selecting the offending faces, and flipping
them. However, many of the faces are near impossible to select,
without affecting faces that are correct.
Any ideas?
– 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]
The best thing to do is to buy Yost Disk#7 with the optimize routine.
You can download a fully functional demo of it from the library to
see how it works. Other than that, face by face (use selection sets
and Hide/Face to help) is the only method I'm familiar with.
>> The best thing to do is to buy Yost Disk#7 with the optimize routine. <<
I'll keep this in mind for the "next" time <G> I couldn't leave it
alone last night, and finally re-created the DXF (I'd erased it after
the original import) and re-imported it with the "unify normals"
toggled OFF.
It worked just fine…. this time.
Michael;
Sometimes Optimize IPAS helps in this situation by showing the actual normals
as arrows and allowing you to flip them on an individual basis.
Good Luck
Zac (AZ-TECH)
Berkeley
Object unify really won't work for a really complex object. The best and
easiest way to deal with it is to get the Yost Group's OPTIMIZE IPAS (Yost IPAS
Boutique disk #7). There's a demo of it in the libs. It will display normals
as little arrows that you can flip by selecting them.
Dave
Michael,
Auto-Unify only works if the object is a single element. If it is composed of
multiple elements then the algorithm will get confused about "inside" and
"outside." This can make the normals situation worse rather than better (it
can also confuse the Boolean command). You should not unify a DXF on import.
Instead, you should separate elements into objects and then use object_unify on
each one. Most objects that come from AutoCAD will have normals that all point
consistently in or out depending on how they were built. It is only objects
that a use builds from faces that may have a mix of normals.
Terry Gilbert
Forcade & Associates
The DXFs that I import are all created in AutoCAD AME. Each object comes in
separate (I put each solid on a separate layer)
While AME solids are created by booleans, and often have separate
primitives, before expoting the DXF, you must perform the "solmesh" command,
which turns each object into a polyline mesh.
Besides, at least one of the objects I had trouble with had been created
from one primitive, adn it's faces were "screwy" also.
The trick, I have found is to toggle off the unify normals switch when
importing to 3DS. As long as 3DS doesn't try to "fix" the mesh, it comes out
just fine.
– 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]