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duderender
04-20-2005, 04:56 PM
In the last while I have seen too many threads started that are the same thing relating to format translations so let's try and consolidate as a single reference.

2D Formats Recommended:
Most applications can export a 2D format. However not all CAD apps will export an AI file, but they will export EPS, so therefore you will need to have an application like CorelDRAW or Adobe Illustrator to convert the EPS file to AI format. However, CorelDRAW for example will export a DXF file.

1) Illustrator (AI)
2) DXF - (AutoDesk)
3) EPS - (Encapsulated Post Script)

3D Formats Recommended:
The problem with 3D formats is the flavours available for translating. DXF for example is the worst format to use for 3D exports as most app native imports only support release 12 DXF and will not read other versions. DXF has change from version to version and it is a hacked format.

NURBS models pose the biggest problem because to convert them most people utilise the IGES format. The problem with IGES is that you have to know how someone exported the IGES file because you can export trimmed and untrimmed surfaces. Not all applications support trimmed surfaces. In addition, assembly IGES files become huge and native importers in applications like Maya, XSI and Max just plain die when dealing with these files. The other problem is the NURBS surfaces must be polygonized for the import. The problem then arises in that you end up with a heavily triangulated file for rendering and this is typically a necessity because you are most likely dealing with curvy surfaces.

The 'hero' in the battle is one of two.

First, grow your knowledege in the availability of formats and purchase a good translator software. The biggest reason to do such a purchase is the ability to deal with native formats from CAD vendors. Companies like Okino and Right Hemisphere both produce great applications (Okino: PolyTrans/NuGraf, RH: Deep Exploration). With these tools you can import a dense mesh and apply polygon reduction to those that require less detail.

Second, hire someone who deals with this sort of thing. The headache you lose by allowing someone else with the translation tools to deal with can be worth it. The resource allocation then allows you to complete the more important task at hand, rendering and client satisfaction.

The recommend formats to translated files are as follows (in order of preference):
1) Native CAD file - Pro/ENGINEER, SolidWorks, Inventor etc.
2) STEP file - .step, .stp : (best for solid models)
3) IGES File - .iges, .igs : (best to have as assembly file, NOT flat IGES)
4) Parasolid - .x_t :
5) ACIS - .sat : typically supported by AutoCAD
4) OBJ (Wavefront is a decent polygonal format since you can associate materials and mapping (coordinate system based) from within CAD apps)
5) STL - .stl : a mass triangle file

If you choose to deal with CAD clients I would highly recommend adding a low cost CAD application like Inovate, Rhino, SolidThinking, Alibre to your arsenal.
1) Inovate: supports assembly formats in IGES and STEP. Exports out in the same formats
2) Rhino: good for single part or flat file IGES files. Currently v3 is weak in STEP and STEP assembly files rarely import
3) Alibre: supports STEP files

The reason I suggest Inovate and Alibre is because the are less than $1000 and they offer a visual tree to interrogate assembly files. The reason this is important is because CAD files that are polygonalized can render your render application useless. Often you cannot receive a tailored CAD export so I would recommend you receive your STEP or IGES file and open them within, for example, Inovate. Using Inovate you delete all of the unnecessary parts and re-export as STEP. Using PolyTrans you import the STEP file and then re-export as a native render format. For Cinema, the Lightwave format works best as you can simply import a Lightwave scene. FBX is an alternate import schema to test with C4D.

If you have specific questions, please post them here with a thread title. This way we need only search through one thread.

I hope this helps.

Regards,

Jason

Per-Anders
04-20-2005, 05:53 PM
It's worth also mentioning for export to Maya/XSI/LW/Max/MB that FBX is preferential (but often forgotten about) as it contains the most scene and animation information. Also anyone looking to import from LW is in a good situation thanks to fairly good support for the native lightwave file formats (.lwo and .lws), though no animation import in the scenes, sadly no export to lwo/lws though.

duderender
04-20-2005, 06:01 PM
@mdme_sadie: good point on FBX.

Be aware that FBX has issues with dealing with textures. Although a small problem, be sure that you include all textures when you pass along your FBX export. I have noticed that FBX does not truly remove explicit paths on export so you may have to deal with the 'relocation' on import.

I will also add that PolyTrans is a very good product at dealing with the DCC-to-DCC application conversion in that it supports a native import for each application in some form (PolyTrans comes with a native plugin for XSI, Maya and Max, for example). Because of the native support you can transfer animations and texture mapping across.

To my knowledge, C4D does import the animation keys from a .lws, but I am not sure of the limitations. Experimenting with some of the content files that LW ships, I was quite surprised by the level of import compatibility.

Ernest Burden
04-20-2005, 07:09 PM
If you choose to deal with CAD clients I would highly recommend adding a low cost CAD application like Inovate, Rhino, SolidThinking, Alibre to your arsenal.

That's my entire business.

Rhino still cannot read a v2004/6 version of DWG or DXF. It cannot import blocks, though it can create them (same is true of Cinema, unfortunately, on both counts).

A very cost-effctive alternative is SketchUp, it reads the newer ACAD files, it imports blocks and it is a fun, easy way to get a 3D model going.

duderender
04-20-2005, 07:15 PM
That's my entire business.

Rhino still cannot read a v2004/6 version of DWF or DXF. It cannot import blocks, though it can create them (same is true of Cinema, unfortunately, on both counts).

A very cost-effctive alternative is SketchUp, it reads the newer ACAD files, it imports blocks and it is a fun, easy way to get a 3D model going.

DWF is dangerous in that it is a "locked format" for web distribution. However, if you own Rhino you may want to use the V4 WIP as it supports the 2005 format of DWG (according to release notes).

The problem with AutoCAD is you don't know if you're talking to someone dealing with 2D or 3D data. Therefore, choose a more appropriate format from your client. If it is 3D, go with the ACIS format and not DWG. However, PolyTrans supports the latest DWG version. If it is 2D info try CGM, eps or DXF is pretty safe (unless it is splines and then you need to use DWG).

I recommended Rhino or Inovate to people solely to do some preprocessing and cleanup prior to running the polygon translation process. Inovate is good for that but the geometry creation takes a bit to get used to. Whereas Rhino's strength is to deal with more hardcore surfaced models (trimming surfaces, projecting curves, etc.).

AndyMcc
04-20-2005, 07:38 PM
A lot of the companies with good dxf/dwg import export get their dwg/dxf info from the open DWG alliance.

Vectorworks, Sketch Up, Alias, Newtek, solidworks. But no Maxon

http://www.opendesign.com/membership/sustain.htm
(http://www.opendesign.com/membership/sustain.htm)

acmepixel
04-20-2005, 07:47 PM
It's also important to note that for Hypernurbs one needs Quads. The .obj and lwo, lws formats support Quad meshes very nicely.

A route to Quad mesh, from a triangulated one, is to import into Zbrush 2, convert to quad mesh and then export as obj.

duderender
04-20-2005, 08:19 PM
A lot of the companies with good dxf/dwg import export get their dwg/dxf info from the open DWG alliance.

Vectorworks, Sketch Up, Alias, Newtek, solidworks. But no Maxon

Maxon has DXF import and export

It's also important to note that for Hypernurbs one needs Quads. The .obj and lwo, lws formats support Quad meshes very nicely.

A route to Quad mesh, from a triangulated one, is to import into Zbrush 2, convert to quad mesh and then export as obj.

Excellent point! OBJ and lwo are quad compatible. In C4D you can also try the Untriangulate tool which will quad-ize. So if you select nothing it will do what it can on the scene or you can polygon select a set to Untriangulate.

AndyMcc
04-20-2005, 08:26 PM
Maxon has DXF import and export


Yes they have it, but (correct me if I am wrong here) theirs is only dxf r12 which was the last one that Auto Desk released for free. If you want to use the more current version you either have to pay Auto Desk a huge fee or get the libraries from the open dwg alliance. The companies that use open dwg have far better dwg/dxf support.

Ernest Burden
04-20-2005, 09:51 PM
DWF is dangerous in that it is a "locked format" for web distribution.

That was a typo on my part. I meant .dwg

You are right about dwf, I don't mess with it.


Yes they have it, but (correct me if I am wrong here) theirs is only dxf r12 which was the last one that Auto Desk released for free.

I think Cinema will read up to a dwg2000 format dxf. I guess I would be better off testing that than posting by memory.

lllab
04-21-2005, 08:39 AM
cinemas dxf import is very weak.
dwg is missing.

rhino 3 can import new dwgs, if you are registered user you can download the free bonus tools. dwg2005 format plus other great tools are included:-)

cheers

stefan

STRAT
04-21-2005, 09:13 AM
nobody's mentioned .3DS format yet ;)

ThirdEye
04-21-2005, 09:21 AM
nobody's mentioned .3DS format yet ;)

which triangulates the mesh, right?

STRAT
04-21-2005, 09:24 AM
which triangulates the mesh, right?

point being? :)

lllab
04-21-2005, 09:30 AM
just do unriangulate in cinema with ngon option on and you get wonderfull meshes, even with ngons(for architecture and technical stuff needed. then 3ds is not so bad and for some workflows even very good.

stefan

ThirdEye
04-21-2005, 09:31 AM
point being? :)

Point being i don't want a triangulated mesh and i don't want to lose my time untriangulating it. I usually prefer obj to 3ds.

STRAT
04-21-2005, 09:36 AM
thats fair enough.

but im just suprised .3DS wasn't even considered in this post.

i'm an architect and been using the .3DS conversion all my working career. it's a wonderfull, easy, solid, reliable format that hasn't once let me down in over 15 years.

ok, so it triangulates. well so what? for architecture it doesn't matter. even for more organic curvey shaped architecture. besides, untriangulating isn't really a problem, and triangulated meshes are sometimes needed.

i understand it might not be the best method for more 'workable' character modeling for instance, but for architecture and general modelling on the whole i'd stick the .3DS format right up there at the top.

:)

ThirdEye
04-21-2005, 09:42 AM
what's the advantage over obj?

STRAT
04-21-2005, 09:49 AM
well for one thing a fair few cad apps, including autocad, dont export OBJ files

and i didnt say it was better, i was just trying to help sing it's praises, as most peeps dismiss it.

lllab
04-21-2005, 12:49 PM
obj does not come in as groups from some apps, it also looses the materials often when importing. with 3dmax i have more luck most of the time. it is nicely grouped as it was in the other app.

obj is a very good format, but cinema doesnt use the mtl.part of it or doeant import uvs. at least whenever i tried. this might be a mistake from my side of course.

stefan

RangTang
04-21-2005, 02:16 PM
Triangulated mesh was prefered because there is no distortion. Four points rule currently because of subdivision, it wouldn't suprise me to see another technology shift that favored 3 points again.
One way I evaluate the effectiveness of a program is that whatever I can put into it I can get out to reuse in another program. C4D is very good at getting stuff in, it has LWS w/animation, 3DS w/animation, and FBX. I would love to get export 3DS animation out of C4D to use in Swift3D for Flash SWF (no, not for web) to get animated vector footage (it is scalable to any size). Now I have to jump from exporting VRML to a conversion program to Swift. I am also looking at Direct x export for the same purpose.

For OBJ there is the free Riptide C4D plugin that has lots of options including materials.

basilisk
04-21-2005, 03:44 PM
just a trick I discovered - if you are exporting a 2D CAD file, it can be worth trying exporting/"printing" to a PDF file, which preserves vector info. This can be converted in Illustrator to an .ai file which can be brought into C4D. This was certainly more successful than taking a DXF file in directly. Don't know if this is generally useful, but it helped me out of a problem

Ernest Burden
04-21-2005, 09:12 PM
just do unriangulate in cinema with ngon option on and you get wonderfull meshes, even with ngons(for architecture and technical stuff needed. then 3ds is not so bad...

USUALLY.

There are times that you creat 'boomerang' shaped polys which can render or display with the 'crotch' part filled in. If you had a wall with punched rectanglular windows, 'ngon' sometimes doubles-over the front surface covering the windows. In those cases using untriangulate to quads is fine.

Also, with imports from 3ds I often find it useful to do an 'optimize' first, because phong smoothing won't work. Then it does.

When there are lots of polys in planar sets you can 'melt' them into ngons, too.

But with all of these, watch the results so you can undo any nasties.

geoffr
04-21-2005, 10:03 PM
I work with product engineers using solidworks and they save out as vrml so that I can import them and make them look nice in the renders (tri's permiting).

Now, obviously, I can do things that they can't (and vice versa) and I would like to be able to give them files which they can work with.

Now, here's the problem: I'm on a Mac.

All of the above applications seem to be windows only. I would really like to be able to save out in a format which they can use.

Any ideas?

duderender
04-22-2005, 06:42 PM
@geoffr: VRML is platform independent. However VRML is not always a coperative format to deal with. SolidWorks should be able to import OBJ or STL files and in one form or another you should be able to do it. Be sure to use an ASCII format so that it can come across from Mac to Windows.

Re: 3DS format - The reason why it wasn't brought up is that it's not a good option coming from a CAD format. OBJ is a long time standard and is preferred over 3DS between DCC apps. In addition, OBJ supports quads and triangles and I believe it handles UVW mapping coordinates better than 3DS.

Between DCC apps, 3DS is a decent alternative. No argument there.

Kuroyume0161
04-23-2005, 04:43 AM
duderender, you hit it on the nose. 3DS brings in the materials, but the UV mapping is limited - very limited. It uses an archaic one uv per vertex format whereas contemporary uv mapping allows for many uvs per vertex. Oh, and the texture image filenaming is very limited - 8.3 (back about 10 years and so). OBJ doesn't bring in materials if the importer ignores the MTL file, but OBJ supports materials, textures, UVW, splines, parametrics, and a myriad of other parameters that most applications ignore. OBJ also supports NGons - yes, it does.

Lovas
04-23-2005, 05:54 PM
No one has mentioned Accutrans in this thread yet. I have good experiences with it, a rather flexible though stable conversion program (with quite an ugly and strange UI, though - but who cares...:) ), It has helped me in converting both "ordinary" and "exotic" formats, in cases when Polytrans failed. Especially useful for converting some strange terrain meshes that one gets from survey services - they are all basically text-based tables of coordinetes, but accutrans lets you adjust the formatting of data before importing... A rather long and interesting list of export and import formats.

It can be downloaded from http://www.micromouse.ca/downloads.html

duderender
04-23-2005, 06:23 PM
I've used it, but I prefer PT as it allows me to use polygon reduction tools and to reorganize the structure of the parent-child heirarchy.

Accutrans is simply a mesh translator. Like I mention before, there is more than just moving vertex data between apps.

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