#Generic 3D -> 3DStudio
10 messages in this thread
Steve, we've been working with plenty of Generic 3DD and CAD users who've
had no problem getting their data over via DXF3DS, so there must be
something unique to Datacad there. There are more options for datatypes
than just polygons with the Generic stuff, so that must be it. (In fact,
the designer of 3DD was one of our testers for DXF3DS and he's really happy
with it.)
If you upload a clearly-documented, simple model that explains exactly what
you're looking for, we'll see what's involved.
– G
Ummm.. You might want to check with Scottv at Generic on that. GCADD 3D
uses 3D faces, which is not supported in DXF if they have more than 4
sides. Polygons with more than 4 vertices are translated into polylines by
G3D on DXF output. If someone is getting a good translation from G3D to
3DS, I for one would love to know how! LAM
Well, I'm not an expert on Generic's products, but Scott should talk to
Peter about this. He designed G3DD and he's been very happy with DXF3DS.
I think they ought to get together and discuss it.
– G
Actually the person you and I need to talk with is LISA, who is the one who
wrote the DXF converter. What we have is good, but there are some really
big gaps where polygons and holes are concerned.
I'll talk to Terry Leker about setting up some sort of meeting.
– G
Gary,
Just go over to GENERIC and in LIB 9 you will find some nice big DXF files
I uploaded. Many of them contain the entities that he is talking about.
For example the side of the JENNY Bi-plane is a multi-verticed polygon that
is translated to LINES in the DXF file because (of course) DXF does not
have a entity type for a polygon with more than 4 vertices.
What we are talking about is coming up with a convention for using the 999
comment fields in DXF as a precursor for that kind of entity, so that you
would know to convert those lines to a polygon. Same would go for a Hole
with more than 4 verticies, or maybe even holes in general.
Hi Scott,
Bug your favorite DXF translator programmer and tell (him, her, it) that if
the multiverticed polygons were written out as 2D Polylines with the
correct arbaxis data then 3DS would put faces on them.
-GB-
I'll pass that on to Lisa.
I'll also tell her you referred to her as an "it"… :>
Grant,
I talked to a few 3rd party developers for datacad re: the conversion of
pgons to plines. They seem to think that they can write a macro to do it.
I did a quick test exporting a few plines out the dxf and noticed a
potential problem. When viewing the dxf file itself, i noticed that each
vertice has X & Y coordinates but no Z coordinates. Is that another dcad
bug or is that the way the dxf standard is written? (hopefully it's a dcad
bug)
I'll keep you posted on the 3rd party progress.
Steve
The POLYLINE entity has several variations. At the beginning of the
POLYLINE definition before the vertex data, there will be a group code 70
followed by an integer number. That number is a flag to describe the type
of polyline. Values from 0-7 mean its a 2D POLY. Values from 8-15 mean its
a 3D polyline. Values between 16 and 63 mean that its a rectangular face
mesh. Values 64 and greater mean that its a arbitrary polygonal face mesh
like 3DS uses. DXF3DS will convert 2D Polylines into faces objects, and
convert the other meshes into faces, but not convert 3D polylines.
One other thing about 2D objects in AutoCAD DXF, even though they contain
no Z information, they can be located at any point in 3D space and in any
orientation based on a cross product of the 3D point and the group 210
codes, simplified in an arbitrary but reproducible way. In fact, you will
see that the POLYLINE header always has a group 30 code for the Z axis,
even for a 2D poly, and always has 210 codes.
-GB-