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celmar
10-11-2006, 04:08 PM
Hello! does anybody has the experience of importing .obj from rhino? I have a lot of problems, no access to the surface editor and the smoothing option, and in layout no shaded solid viewport, just wireframe...
maybe it's a matter of normals, or something I don't really understand... any help? Thank you!!!!

lesterfoster
10-11-2006, 07:23 PM
Hi. I have some experience of importing and exporting different formats from other cad like programs into and out of LW. Can you give more detail on what you are trying to do? I have found that not all methods of drawings work with importing and exporting between LW and other programs. If it is a nurbs object, you may have some problems.

Have you tried exporting from Rhino as a *.lwo format, then opening it up in modeler??

You can also try exporting from Rhino as a *.stl format. Then use the STL importing script that you can fined here.
http://www.chromecow.com/downloads.htm

Scroll down a bit for Sean's stl exporter

Ztreem
10-12-2006, 01:10 AM
When you import an object from a CAD program you usually don't have a surface attached to your object, so that's why tou can't access the surface editor. Load it in modeler an press 'q' and click ok, now you have a surface on your object. If you have different surfaces you have to select the poly's connected to that surface and give them different surface names. I hope this helps.

ColinSmith
10-12-2006, 07:34 AM
My workflow for Rhino to LW is more or less,

~ Select the parts of an object which will all be the same LW surface in Rhino

~ Export those from rhino as 3ds, fiddling with the mesh options to get the kind of poly numbers I want.

~ Open the 3ds in LW, select all polys and assign them to a surface.

~ Maybe reduce polys to get back to something nearer quads, might not work so well depending.

~ Repeat for all the different parts/surfaces. Cutting and pasting them into the same base LW object.

~ Merge points in LW at the end.

Not exactly the nicest workflow, but it gets there.

You can help out by modeling in Rhino with polys in mind, and by overlapping edges where they are curved (so you don't need an exact edge to egde match of 2 different poly exports)

Depends what you are doing, works OK for Architecture.
I read Rhino4 will have a lot more abbility in working with polys and meshes.
Phew! ;-)

Ztreem
10-12-2006, 09:14 AM
I read Rhino4 will have a lot more abbility in working with polys and meshes.
Phew! ;-)

Imagine how nice it would be if Lightwave supported NURBS.:D

celmar
10-12-2006, 09:29 AM
thank you really for your help!... as I begin to learn lightwave, having done all my work precedently in carrara, from rhino and zbrush as modellers, I should want to use in a first tiome lightwave as a rendering soiftware, but keep my habits to model in nurbs... I know, zbrush is poly, but in fact you never "see" them... I've seen some rhino objects coming fine, once smoothing, in lightwave, although I have often the problem of "shaded solid" transformed in the bounding box; the hint you give me , to use the LW export from rhino, make all that problem better, if not solve totally;
I used, with carrara5, to, say for exemple: modellling a complicated scene in rhino, mostly in nurbs but also using on zbrush meshes the new command opf rhino 4, then export successively all the parts in carrara, each part arriving as a single object, ( for example, all the screws of the shield arriving together), with the execption of the zbrush things which arrive with their texture, due to the 3d painter "projection master"...
do you think that sort of workflow is possible, in a first time, to get similar in lightwave 8?...

celmar
10-12-2006, 09:31 AM
ztreem, there are very few rendering soft which use directly nurbs,; I think?... one is, I believe, realsoft, but it is rather unknown...what would be the advantage to render directly nurbs?... more softness?

Ztreem
10-12-2006, 10:54 AM
ztreem, there are very few rendering soft which use directly nurbs,; I think?... one is, I believe, realsoft, but it is rather unknown...what would be the advantage to render directly nurbs?... more softness?

There is quite alot of well known 3d apps that renders nurbs, for example Maya, 3DSMAX, XSI, Cinema 4D and Truespace just to mention a few. The benefit is that you don't have to freeze your mesh into a polymesh of milions of polys. You have all your surfaces intact so it's just to setup the materials. It's easy to select your object or surfaces if you want to resurface them or remodel them... I can go on and on. Simply put it's alot easier.
I feel more like LW is one of the few 3D apps that not supports NURBS and for visualization it's very important. Another sad thing about LW... :grumpy:

Ztreem
10-12-2006, 10:56 AM
Maybe I should add that these apps don't render NURBS, not many or any apps do. They convert the NURBS surfaces to polys at render time, but that doesn't really matter. Even Rhino converts to polys when it render.

Exception
10-12-2006, 11:13 AM
NURBS are not too different from MetaNURBS. You can't properly convert NURBS between 3D programs anyway because they all intepret them differently, it is never a smooth transition. NURBs are difficult to edit and come with their own set of problems. MetaNURBS are much more flexible. The only application where NURBS start to become really important is CAD/CAM. MAYA/ XSI/ 3DS only have very limited NURBs implementation, and they're not that useful anyway. For real NURBS you have to use Solidworks, Microstation and so on. And, of course, Rhino.

Ztreem
10-12-2006, 11:26 AM
Yep, maybe true for modeling but for rendering they work perfect. ( and that's what we talk about here)

Ztreem
10-12-2006, 11:29 AM
I agree that metaNURBS is more flexible than NURBS (in some occasions) and in alot of occasion it's the other way around. I can model some stuff in NURBS in minutes that you will have a **** to replicate with SDS.

ColinSmith
10-12-2006, 01:17 PM
Coming from the CAD world I find that modeling in Rhino just fits with the way I think about doing stuff.
I am trying to do more modeling in LW, but I find I need to think a lot more, and get used to a different way of working.

Ideally I'd go with a Rhino that worked as a poly modeler, with all the snaps and cad modeling tools. I hope v4 will be more like that.

I understand there is a nice translator plugin for Rhino and Max, that seems to import native Rhino models as a SDS model (more or less), where you work with it as a lower poly proxy and set your required poly detail at render time

celmar
10-12-2006, 03:12 PM
well, I think that the only render engine using nurbs AS nurbs is realsoft 3d... as it is a rather "ghost" program, of course, it's rather unknown... all other tran,slate in poly, and the nurbs of C4d, have nothging to do with nurbs like rhino... but I don't know if it's a real advantage to render native nurbs, without translation in poly... the realsoft gallery is not very clear, about that, not the "ultimate" render engine for nurbs... but I should want to keep nurbs in my workflow, it's so fast to model in rhino!...

Sensei
10-12-2006, 04:01 PM
Imagine how nice it would be if Lightwave supported NURBS.:D

It does support.. You can have them in EasySpline by using TrueArt's Bezier splines which can work in B-Spline mode (if you have more than 4 control points per curve)..

lesterfoster
10-12-2006, 07:40 PM
What a fascinating discussion. But I do have a question. What are the differences and similarities in modeling with splines with LightWAVE compared to modeling with Nurbs in a program like Rhino or Solid Works.

celmar
10-13-2006, 02:17 AM
another question: at the import of the rhino object, in .LWO, there are strange appearance, due probably to the necessity to flip the normals... I though it was done by clicking "f", but it doesn't work... what's the good way?

Ztreem
10-13-2006, 02:23 AM
It does support.. You can have them in EasySpline by using TrueArt's Bezier splines which can work in B-Spline mode (if you have more than 4 control points per curve)..

Ok, What I'm looking for is NURBS surfaces and .wire, .step, .iges import support. This you can't do with easy spline, but maybe you can write a plugin for handling NURBS surfaces in LW.:thumbsup:

Ztreem
10-13-2006, 02:39 AM
another question: at the import of the rhino object, in .LWO, there are strange appearance, due probably to the necessity to flip the normals... I though it was done by clicking "f", but it doesn't work... what's the good way?

Flip should do it, but you have to be in modeler for it to work. I usually just tick the 'double side' in surface editor.

Ztreem
10-13-2006, 02:42 AM
What a fascinating discussion. But I do have a question. What are the differences and similarities in modeling with splines with LightWAVE compared to modeling with Nurbs in a program like Rhino or Solid Works.

The biggest difference is that you can project curves and trim surfaces without losing control over the surface. I can do some screenshots if you want a deeper explanation.

celmar
10-13-2006, 03:17 AM
I have always problem, setting up a workflow from nurbs, (rhino4) to lightwave; as you see in the picture joined, in 1, it's a simple but rather "typical" object imported in LW; there are a lot of problems, in the translation of the joined surface... in2: the same object in carrara5, wich is, like in rhino, perfectly joined... what would be the set up, in LW, to optimize the objects from nurbs?

Ztreem
10-13-2006, 03:33 AM
Hmm, Never had any problems like that. Then I don't use Rhino that much anymore. I usually use Studiotools at the moment when doing NURBS and it usually works perfect when freezed to a mesh.
Maybe you should try to merge points in modeler and see if it helps.

celmar
10-13-2006, 04:08 AM
effectively, thank you, it helps!.. not solving totally, but a better look...

ColinSmith
10-13-2006, 07:09 AM
I'm not sure of how you are working, but if you join all the surfaces into one object in Rhino and export from that then the polymesh should have no edge/join problems in LW.
If the Rhino sufaces are not joined then there is no guarentee that the poly meshes generated will share points. This becomes more work when you want 2 different LW surfaces to join smoothly......

celmar
10-13-2006, 08:31 AM
well Colin, the surfaces was joined, in rhino, before... in other words, it was a single object... it seems that I have another problem, probably due to the normals: as You can see, the fur is on the wrong side of the geometry, "inside" the head... also, with 6 or 7 objects having different furs, I get crashed a couple of times...

SaturnX
10-14-2006, 12:22 PM
Imagine how nice it would be if Lightwave supported NURBS.:D

Yup.
Converting nurbs into polys... makes life painfully slow.
Especially when working with stupidly heavy geometry.
That old modeler speed boost would be nice.

Exception
10-14-2006, 03:34 PM
well Colin, the surfaces was joined, in rhino, before... in other words, it was a single object... it seems that I have another problem, probably due to the normals: as You can see, the fur is on the wrong side of the geometry, "inside" the head... also, with 6 or 7 objects having different furs, I get crashed a couple of times...

Your polygons are flipped.

Take the model into lw modeler, press 'f' on the keyboard or 'Flip' in Detail -> Polygons. Save the model.
You can also turn off double sided now, which creates longer render times and can cause errors in rendering.
What kind of crash are you getting? during rendering or during working? Layout or modeler, or? What module is creating the crash?

Also, to get rid of those seams do the following in modeler:
press 'm' to merge points automatically. Make sure you are in polygon selection mode. Press 'w' for the statistics panel. press the '+' in front of 1 and 2 point polygons. Delete. Make sure the surface is set to smoothing with a high enough angle (more than 60 or so). if there are still lines, marge again, but this time not automatic but give it a range that you think will close the gap. Repeat the rest. LW is very powerful at cleaning up geometry if you get to know it a little.