View Full Version : pro/E to lightwave question

07-07-2009, 03:24 AM
i have seen lightwolf's and chrome cows input on an stl plugin see here: http://www.newtek.com/forums/showthread.php?t=2300&page=5
cheers guys this helped alot, as the version of polytrans i have is getting a bit old and i guess the x_t format and export from pro/e has moved on a bit.
but i noticed pro/e can export .obj files but for the life of me, well the pro/e modeler we cant get it to export anything from pro e as it wont select parts to include in the object.

now using the .stl export i can get some pretty nice objects into modeler but the tessellation seems to be a bit low on curves so on smoothing you can still see the triangles.

so does anyone know how to either get an export in the .obj file format from pro/e or what chord hight and angle control to use to get the best results.
i have been playing with it but i have a job looming and the funds for polytrans upgrade may not be there so this it the only route going at the moment.

cheers for any help

07-07-2009, 04:51 AM
changed the chord value to its minimum which gives a smoother model/curve though the curve setting is a bit hit and miss. but am getting some parts that wont write out to the stl file. cant see any reason as other parts just as thin and complex have written out

07-07-2009, 07:27 AM
Hi Mike,
I've encountered the same problems when exporting .obj from Pro/E. I usually use "Render (*.slp)" when exporting, which in my opinion is easier.

However, the following procedure should work for exporting obj:
1. In the Save a Copy to obj dialog, press the Add button (alternatively click the All button and skip steps 2-3).
2. Ctrl- or shift select the parts and sub assemblies you need to export
3. Click middle mouse button (or click the OK button in the small dialog)
4. Now select a datum plane to define UVs (this is the part I usually miss)
5. Again press middle mouse button.
6. Adjust parameters. Low Chord Height=more detail, high Angle Control=more detail.
7. Click Apply or OK

Hope that works for you to!
I would recommend the SLP route though since it's easier, it works well with PolyTrans and the UVs offered by OBJ is mostly crap.

07-07-2009, 07:37 AM
cheers falogfx
i followed all that up to point 4, not being a hardened pro/e user i dont know what a datum plane is, which is probably why i get no objects selected in the dialog.

the stl route is working but i beleive that some of the parts arent solids and are quilts which wont export to stl.

so how do i solidify these.

looks like li need to do some learning as this job could be a constant one.

also on 2 of the parts theres are sharp protrusions from the part, which are obviously errors but they may be stopping the import. any ideas.

sorry cant show screen shots as its not disclosable yet.

07-07-2009, 08:07 AM
I don't know that much about Pro/E either. I mostly use it for file conversions and occasional modeling.

I'll try to attach a picture showing where you find the datum planes.

Regarding the missing parts in your exported stl-file.
Have you used any imported geometry in the Pro/E files, say IGES, STEP or anything not native Pro/E? Imported geometry are often difficult to export to polygons.
You can check your model for faulty geometry by setting Pro/E viewing options to one of the wireframe modes.
Faulty parts of the geometry will show up in a different color then the rest of the model, usually a purple tone.
These faulty parts need to be fixed and to be honest, on imported geometry it's a real pain and often not doable at all. With the proper Pro/E license you will have some tools to works with in part mode.

You might also expect holes in the exported mesh, especially on bolts, screws, nuts, and complex rounded corners etc.

I'm sorry to say that I don't know how you should do to solidify quilts and surfaces :(

As for the strange protrusions you get, I all can come up with is to check your model/assembly for faults as stated above.

07-07-2009, 08:16 AM
ah so if i enclose the whole object in datum planes(including the error protrusions) i should be able to export to obj.
other problem i have now discovered thanks to your note on wireframe colour is that the bulk of the model is in purple. so all this needs to be fixed. i have found how to do the solidify but it doesnt seem to be working, maybe i need to thicken first or something, i'm now really shooting in the dark here but its as new skill to have.

07-07-2009, 09:03 AM
Actually, if your model is created in Pro/E there should already be at least three default planes. If not you need to define a new plane. It can be done using a couple of the model's surfaces as reference for the new plane. I don't think there's any need to define more than one plane though.

I'd recommend using the SLP exporter in Pro/E instead and give it a run through PolyTrans, no fuzz with planes and it also retains colors from the model as separate surfaces, meaning you can use those in LW Modeler to split up the object. SLP has the same problems with faulty models however.

Given that a large portion of your model is rendered purple I'd guess it's all imported geometry. I've been pulling my hair over repairing such the last seven years or so. Should you find a nice solution, please tell me :)

A trick that sometimes work with faulty models is to use the VRML export in Pro/E. It seems to use a different meshing procedure than the other polygon exporters. The meshing is horrible but might give you something to continue working on in LW.

07-07-2009, 09:11 AM
currently looking at fixing easch individual part, though the quilts are what are causing the most head aches, so glad i dont use this on a daily basis

07-07-2009, 10:08 AM
I hope you get things working, good luck!

07-07-2009, 03:14 PM
Purple edges are fine, that means they are merged surface edges (joined).
The ones to worry about are pink edges, this means they are open.

If you have some pink edges in there, that is why you cannot solidify the quilt. ProE is fussy about exporting in some formats if the model is not watertight.

Is the model imported?
If so, you can right click on the feature-edit definition. Then go Edit (up top), feature properties. A box will pop up with an option to make solid. Click this. THen click the green tick (exit feature/done). If the edges dont go white, you have open edges. In which case you can use the import doctor. You can access by editing definition on the import, then going Geometry - Import data doctor/repair geometry, depending on the cut of ProE you are using.

One route you can take is to get the latest demo of Rhino (30 saves) export from ProE as a STEP, import into Rhino, then export the model from there.

Let me know if you go this route, I can let you know what settings to specify to get a decent mesh.

07-07-2009, 05:17 PM
i managed to get a gvery good export from NX unigraphics of an stl file that i can now work on, problem i have now is that the other model i need is only in a an x_t unigraphics file which suprisingly the NX softwear (that created it) doesnt read (so i'm told).
anyway now i have one file i can use and one that still has errors on the quilts. they appear to be purple but i cannot export them as an stl file which is a shame as i have got alot of very clean data so far in the stl format.
anyway its getting late now and as i have made some progress i'm calling it a night.


i'll have a look at your suggestions tomorrow gristle

07-07-2009, 09:10 PM
I don't have Pro/E, SolidWorks or the other solid modeling programs so I can not say how to control the density of the polygon meshes when exporting files.

Pro/E appears to do a good job of exporting 3D meshes to VRML files that I have received for testing in AccuTrans. I haven't been sent any VRML files for a couple of years so that may have changed.

There is a possibility that some triangles will have their surface normals flipped so that they appear to be missing when viewed in LightWave. This problem is easily fixed using the 'align surface normals' module in AccuTrans.

When Pro/E exports an assembly it creates a series of VRML files with one master file. Reading that master file reassembles the whole model.

There is a problem with the VRML export from Pro/E. The routine that creates a mesh to fit around a solid can create many mesh segments when there should be only one segment to fit the entire solid. A simple bolt, for example, could consist of two or more segments each saved to its own IndexedFaceSet node in the VRML file.

There is no way of knowing which IndexedFaceSet nodes should be combined together and placed on a single LWO layer. Thus when a set of VRML files is read, there could be hundreds or even tens of thousands of layers after import. This leads to a big problem of which layers should be combined together.

The solution is to use different colors in Pro/E to color the various parts of the assembly according to how you want them to form layers in LightWave. After the set of VRML files is imported into AccuTrans, use the "Tools -> Merge Layers With Same Materials" menu command and the high number of layers will be reduced to the number of distinct colors used.

Earlier I mentioned that many mesh segments can be created for a simple solid like a bolt. If you export to an STL file by part rather than the whole assembly to one STL file, all the segments are written to the STL file as though they were one mesh. Use the "File -> Multi Open" menu command in AccuTrans and you can read the whole set of STL files at one time and each STL file will be put on its own layer and the assembly will be rebuilt from all the parts.


07-08-2009, 09:37 AM
thanks for that tip micro mouse that worked a treat, even include those pesky quilts that just wouldnt convert.
would be nice to be able to specify the mesh density though as the stl files i got from the prt files are really dense and give a sub-d look.
they render fairly quick too though they will need some post work as you get that 'stretch' look in the renders with smoothing on.

07-08-2009, 01:10 PM
The meshing routine for solid models definitely needs a polygon density control. Maybe one decade the CAD companies may get around to it.


07-10-2009, 04:13 AM
Some good suggestions here, I'll sure try them out myself.

Purple edges are fine, that means they are merged surface edges (joined).
The ones to worry about are pink edges, this means they are open.

You're correct about the pink color for indicating open edges, not purple, my mistake. I didn't have a model to check with at the moment. Sorry for any confusion.

07-10-2009, 04:29 AM
the purple ones are still causing me problems as they just wont export to an stl file,as they are seen as quilts and not solids and just wont convert to solids (solidify), the only route i can take with those is the vrml one at the moment but they just dont give the resolution i can get with the stl ones.
so i have 2 models that look very good (even with smoothing off as its needed to avoid the triangle render stretch look) and 2 that look lower res which is a problem at the moment at they will just not look realistic enough. i'll continue to find a way to change this though.

07-10-2009, 06:51 AM
Try Gristle's suggestions to fix the model.
You probably still have some pink :bangwall: lines in your model, you need to get rid of those. Zoom in and search for them.

With risk of stating the obvious, have you increased the quality level during VRML export to high? It's under the Setup button in the export dialog.

I think the density of the mesh is size dependent, so a mix of large and small parts in an assembly gives low density to the smaller parts. Maybe you can split up the assembly and export it in portions? Just hiding objects might also work the same but I dare not say.

Rhino could be a solution to your problem. Haven't tried it for a while though.

Right Hemisphere's Deep Exploration CAD Edition handles Pro/E files. I just had a try at a model that couldn't be exported from Pro directly, Deep Exploration opened and meshed it just fine. That might be just luck though :) And it's quite an expensive piece of software.

A trick that actually has worked for me a (very) few times is this.
Load your assembly
Open the troubling part.
Do whatever you can think of to fix it.
Now, save a copy to "Photo Render (*.igs)". This will create an IGES file that for some reason seems to be simpler than the usual IGES export.
Import the new IGES file and if you are really lucky it will now be fully functional.