NURBS. They can't hurt you anymore!!! [Archive]

mrys

06-28-2006, 5:43 PM

Few last days I was trying to model something in Max using Low Poly-Meshsmooth method. As you know I'am rather Rhino gay, so it is mean that curves and NURBS can't fear me. But I have impression, that most of us using poly modelling rather then NURBS. And most tutorials are for Polys rather.

Each of method has strong and weak sides. At last what we fight for is final image - The way to this stage is less important.

After this too long introduction lets go to the core:
My proposition is to start thread about NURBS modelling (Rhino, XSI, Maya anything) to show some methods, to help each others by own skills and discoveries. My post about wing-fuselage fillets was a trial for me to write something useful for others and some of you find it useful. I learned many things form your posts and posts on other forums.

What do you think about?

Pablo_nemesis

06-28-2006, 8:47 PM

I would like to see some of that, i almost have no idea how to use nurbs, exept some basics, tryed some tuts but cant understand them ..

mrys

06-28-2006, 9:27 PM

And it is an idea: no theoretical problems, but real, unique solutions. We would no talking how to build another sport car, but how tu build fuselage of airplanes, turret of tank etc etc. How to get correct wingtips, how to divide our model for aother applications for rendering. It can be something like collections of usefull tips and tricks for NURBS.

I think, that NURBS modelling is so different then polymodelling, that it would be good to have this "medical kit".

kevjon

06-28-2006, 10:44 PM

myrs

This is a great idea and I am all for it. If you have the time to put together something, I think a lot of people here will get something out of it.....including me. I've done enough sub-d poly modelling to know this is time consuming and sometimes frustrating way to model aircraft....and I am always thinking there has got to be an easier way.

I have tried out 3 nurbs packages so far and they all seem to contain the same tools so if you teach how to use rhino nurbs any of the other nurbs packages will likely have similar tools.

BTW All the nurbs packages I've tried so far have the same problem. They are good at creating nurbs surfaces but have very poor meshing utilities, which at the end of the day you need to uv map and texture your aircraft. Only powernurbs (which is a plugin for 3DS Max) has good meshing tools. Rhino's mesher is aweful and I've just tried out solidThinking and that mesher is better than Rhino but once again won't mesh over the joints between nurbs surfaces.

I'd be interested to know from XSI users if the nurbs tools in that package are any good and if you can get a good mesh from the nurbs surfaces you create. If you can then they will find a new customer.

mrys

06-28-2006, 11:05 PM

So the TEAM is born;)!

I'am still testing powernurbs plugin, and get very promising results. There is no ideal, sometimes few surfaces are lost in importing, but result is much, much better then by using native Rhino mesher or Polytrans. This last crashed all time I was trying to import Rhino files directly. I had to use "around" way by IGES for Polytrans format.
Hmmm... maybe show sometning?

kevjon

06-28-2006, 11:57 PM

So far I've never had a crash importing Rhino files in max via the powernurbs plugin but I have only ever imported parts of the model at a time rather than the whole model in one go.

Anyway, I think the meshing issue is a very important part of nurbs modelling and something that needs to be resolved before spending a lot of time creating a nice nurbs aircraft only to find it wont render well or be very difficult to uv map due to a poor mesh.

For max users the cheapest option is to buy powernurbs as it gives really powerful nurbs tools which are parametric in nature and a good mesher. It also allows you to import Rhino models should you wish to model in that application.

Still be interested in hearing from anyone who as used XSI's nurbs tools and whether they are any good. Will do some research on it and see if I can download a demo to test out.

mrys

06-29-2006, 12:36 AM

So far I've never had a crash importing Rhino files in max via the powernurbs plugin but I have only ever imported parts of the model at a time rather than the whole model in one go.
It was no Power Nurbs but Polytrans (Okino) - Standalone application, very good 3D translator. Power nurbs working almost perfectly.

But let see how it is working.

Here we have fuselage of Reggiane Re-2005 straight from Rhino

433

I signed by red lines critical points of model (small arches)

And after export/import

by native Rhino mesher into 3Ds format: 434
by Polytrans (via IGES into 3Ds): 435
by PowerNurbs plugin: 436

As you see Polytrans gives smalest count of polygons, but lost many details. Native mesher with medium settings gives to many polygons with to many errors. And almost ideal - Power Nurbs. Mesh need some tweeking, but not much.

Just for comparison: 437

kevjon

06-29-2006, 2:04 AM

Thanks for posting this information mrys....it illustrates very well the problems faced by nurbs modellers.

Well..... powernurbs get my vote ! That mesh looks good and having tried it I can say it is pretty good and with more tweaking the polycount could be lowered even more if you needed to create a mesh for a game engine for example. 15,000 polys for a whole fuselage is pretty efficient for a high poly render that can stand up to very close renders.

I am quite surprised by polytrans poor meshing qualities. Many Rhino users have recommended this software as the best way to convert the nurbs surfaces to a mesh. It looks very ordinary....glad I never bothered wasting my time trying it...let alone purchasing it.

One possible way to overcome some of these problems is to split up your nurb aircraft into individual panels so that the mesher can deal with less complex shapes.

mrys

06-29-2006, 4:54 AM

One possible way to overcome some of these problems is to split up your nurb aircraft into individual panels so that the mesher can deal with less complex shapes.

And in case of using IGES for Okino and Polytrans model is exploding into single surfaces. Effect: many "leaks" between surfaces.

kevjon

06-29-2006, 5:15 AM

So what do you think is the best way forward for people who might want to model with Rhino but use other applications for rendering and uv mapping but don't have 3DS Max and Powernurbs ?

zarroun

06-29-2006, 5:59 AM

I've never really worked with NURBS myself, but I used to work with someone who started his models in Rhino and then took them into Lightwave. He almost always split up his models, like you said kevjon.

I think it's a great idea to start a seperate NURBS section. I sure would like to know more about them, so my support is in.

mrys

06-29-2006, 6:24 AM

So what do you think is the best way forward for people who might want to model with Rhino but use other applications for rendering and uv mapping but don't have 3DS Max and Powernurbs ?
As I read in few posts cooperation between Rhino and XSI is promising. Never tried it by myself. Probably Maya will be good also (I've read somewhere, that in base Maya and Rhino lays the same rules of NURBS description).

And about splitting into separate surfaces - it is generally good idea. There is no problem in Rhino with splitting or not splitting, but meshing. If it will be improved in next version problem will disappear.

I think that the best in this moment is when you can export model from Rhino WITHOUT meshing it as NURBS. No matter then, if your model is splitted or not* , cause meshing is done by mesher native for apps when you will be texturing or/and rendering.

In case of "simple" shapes, as fuselage without holes for guns, cockpit etc, (just "shell") native Rhino mesher maybe is not as bad. Unfortunatelly no matter whitch method we use (native, Polytrans, PowerNurbs) it gives us always triangles, not quads.:(

* - IMO non splitted multisurfaces are more smoothly after export.

kevjon

06-29-2006, 7:17 AM

I find it strange that programmers cant design a max meshsmooth type modifier for nurbs surfaces. It must be something that is in the too hard basket.

I think that the best in this moment is when you can export model from Rhino WITHOUT meshing it as NURBS

I think your suggestion is a good one but I know in max it creates a kind of low poly mesh when converting nurbs to polygons and then you have to go around a weld all the vertices of your mesh where the joints in the nurbs surfaces are. This process negates the speed benefits of modelling with nurbs in the first place. Also makes triangle meshes.

I have been reading about Rhino 4 but as far as I have been able to tell, it doesn't look like the mesher will be improved. Strange really, not sure what most Rhino users do with their models....it can't be uv mapping and texturing.

roshent

06-29-2006, 9:20 AM

Most use UVmapper, http://www.uvmapper.com/ , and I'm not sure if we're on the same page here, but 4 does have new mesh tools. In basic terms they said they would give you the same present NURBS tools for meshes. I haven't got a recent beta, but the one I saw only had limited new mesh tools. Maybe a current beta has, but I'm a bit too busy to check it out now. If your a registered owner of Rhino you can always download the current beta, a link is provided on the McNeel homepage.
They change the beta everything 2 months or so.

About that calculation method Mrys was talking about with regard to Maya NURBS that's not too far fetched, just dont know if it's real. McNeel is made up of (disgruntled) Autodesk/Discreet employees who started McNeel Rhino, a selection of those programmers went to Alias Maya and are now since the take-over of Maya by Discreet again part of Discreet MAX. I wouldn't be surprised if the mext MAX release has better Nurb tools.... but then again, don't count on it since there is hardly any rumour about what the maya and max programmers are doing right now...

kevjon

06-29-2006, 10:47 AM

Posted by Roshent
I'm not sure if we're on the same page here, but 4 does have new mesh tools.
My understanding about the new mesh tools (from what I have read) are new tools for manipulating the mesh but not for creating it in the first place. As I have only ever used a downloadable demo version I'd be interested to hear if my understanding about the mesher in the new version is incorrect. Let us know when you have time.

Just had a look at uvmapper. Looks really good and the price is excellent. Only problem is that the program is for uv mapping polygons. As you can see from mrys previous post, Rhino produces polygon meshes that really aren't up to scratch. Lots of holes, bad joints and smoothing errors that would take a long time to fix manually. Is uv mapper somehow able to fix those mesh problems/errors in a more automatic way? If it can then it would definitely be the solution to the mesh problems.

roshent

06-29-2006, 11:46 AM

Personally I never used UVmapper, so can't comment on that one... It's just that I think it's the most used in the Rhino community.

Okay, I downloaded Rhino Beta4 666 (6 june 06), and some of the options still don't function, the buttons are there, but the tool is not. I off course have not played long with it, and just used some of the meshtools on a project plane of mine. That one is (flightsim) low-poly'ish I can see some added tools to the mesh menu like Mesh trim and mesh split together with the ones from Rhino3 Match mesh edges, Boolean and Intersect meshes.
The options that is not working right now and might fancy you is "Mesh from closed polyline" (at least I haven't got it working in the short space I tried it). Off course being a beta it's not sure if these tools shown now in this beta stay in or are just as they call it "prototype commands" for new tools...
Other tools that came across as new to me :
Extract Mesh from NURBS control polygon.
Convert quad meshes to triangles ( not seen the reverse though)
Mesh from points
Mesh from height field

kevjon

06-29-2006, 1:23 PM

All sounds good roshent. Not sure what some of the new mesh tools really mean.

Keep us posted if you discover or find out more as the beta program progresses....if there is anything to get excited about ?

Here is a couple of commands in the new version which look promising and I look forward to downloading a trial version for testing of these things when it is released.

Mesh (Render Mesh): Both the Jagged & Faster and Smooth & Slower settings have been changed to use the new Density control. Our experience is that smoother meshes with fewer polygons are generated faster than with the old settings.
Mesh command: A new meshing parameter, Density, gives a scale-independent control of mesh density. This setting is available in the Mesh command and in the Mesh tab of Document Properties.
Mesh command: The Simple Controls slider has been changed to use the new Density parameter availabe in the Detailed controls.
Mesh: The mesher will now put edges of quads along curvature discontinuities (like the ones you get when you extrude a G1 curve made from planes and arcs).
QuadrangulateMesh command: Changing options incorrectly deselected the mesh. This is fixed.Anyway mrys and roshent...not much we can do ATM but wait for the V4 to be released.
Back to the original topic. I think it would be great if you could do a tutorial or pass on tips of modelling with nurbs. Anybody who has software with a nurbs component can trial some of your techniques out.

One area I am really keen to see is how to model vents and openings in cowlings, wings etc. For example the ones on F4U4 corsair cowling or F4F Wildcat cowling. How to model them and get them to blend into the cowling. Seems to me they would have to made up from a series of surfaces but you might have some good techniques to deal with them.

mrys

06-29-2006, 5:38 PM

One area I am really keen to see is how to model vents and openings in cowlings, wings etc. For example the ones on F4U4 corsair cowling or F4F Wildcat cowling. How to model them and get them to blend into the cowling. Seems to me they would have to made up from a series of surfaces but you might have some good techniques to deal with them.

You mean that: 443

I had to do something similar in La 11. It is a little trick, but sometimes works.
444

kevjon

06-30-2006, 12:11 AM

Yep, those sorts of openings, they look very difficult to do with nurbs. the La 11 looks good though.

mrys

06-30-2006, 12:38 AM

Here you have explanation of my method. It is not the best that would be done, but after long strugle with this shape I chose this one, cause in this case it is enough good (I think).

I supose, that image should be clear for you. The key is thin, front surface, build on three curves: intake edges and front cooling edge.

kevjon

06-30-2006, 2:07 AM

Thanks mrys, your method is clear for intake that are flush with cowling front and works well.

I guess some of the tougher shapes (http://www.aircraftresourcecenter.com/AWA1/101-200/walk136_Corsair/images/Mvc-056s.jpg) that are not flush with the cowling front I will need to experiment.

mrys

06-30-2006, 4:54 AM

Yuo have right. It is a little bit harder to model this properly. Good luck:).

Few hours later....

I was thinking about and have some ideas...

mrys

06-30-2006, 9:01 PM

I was trying to build sample cooling with vents, similar to that on your attached image. I think, that good way should be divide whole cooling into two parts: front with vents and rear. The rear part will be easy to get - just make some crossections and lines.

The front, main part is more difficult. As you see it is created by three surfaces: main front, vent outside and vent inside. All are joinned into one multisurface. Border lines, where vent intersect cooling can be filleted. Or after exporting into the Max vertices could be moved to get smooth effect.

Other method could be blend surface - need to prepare biger holes, sweep2 rails ect. It is good to "cut" cooling part exactly as on blueprints

I attached files in zip format. It is only provisional version, so don't wait for wonderful result - it is only one way to final results.

kevjon

06-30-2006, 10:47 PM

Thanks mrys. Looks like a good solution for all sorts of aircraft problems. Another one similar to this is the intakes on jet aircraft which could be done in similar fashion (depending on subject). Will give it a try.

Bigtodd

07-01-2006, 3:09 PM

Marek,

Thanks for posting the curve files. I will try out what you suggested today.

Todd

mrys

07-06-2006, 6:08 AM

Working with models in Rhino I usually made glass for windows and canopy as oneside surface. But if you want to get "true" glass and use such effect as caustic you need "real", two sided mesh with "solid" spece between sides.

Here is my method to get this.

1. At first we have nose, glass part of Mosquito Mk IVB.
I always working with layers, so here are three: exterior (frames), glass and interior (frames). Our nose is now on exteriors. I made fourth, additional layer for helpers. I made it invisible and put there copy of "nose". On this layer I keep everything - lines, cuted surfaces, helpers - what is not use fo object, buy could be useful to get back, if I something will go wrong.

2. Next step is to make "interior" part. I make it by offset surface. I chosed 0.2 value, but it depend on unique model. Non used part I cut off by the line, to get flat back side.

500

3. And now we need to cut off glass parts. Making this by projecting lines onto surfaces, cutting them where necessary and the same doing on "interior". After that we have almost whole frame for glass.

501

4. Now I join "naked" edges by blend surfaces. Unhide "glass" from exterior and offset it by small amount: 0.05. Old surfaces we moved to helpers layer and new offset again by 0.1. As result we got two sides of the glass. And again joining inner and outer surfaces by blend or loft edges. Now we have "solid" glass panels...

502

...with solid frames

503

kevjon

07-06-2006, 6:32 AM

Very neat solution and very simple.
I would probably give everything thickness in max with the shell modifier after converting the nurbs to a mesh to reduce the amount of cleanup of the mesh.

mrys

07-06-2006, 6:51 AM

Yes, shell modifier in Max works very good and fast, so if you imported object from Rhino it is very good option. But, what about fillet edges of "shell"? I like to have rounded ednes of frame to get some extra reflections here.

kevjon

07-06-2006, 7:10 AM

I personally dont worry about filleting edges of canopy frames as I make my glass flush with the outside of the canopy frame. I think this is how it is in real life on most aircraft ?

If you do want or need that small fillet then definitely it is the best solution to model the thickness in Rhino.

Spinner

07-06-2006, 9:56 AM

Not WW2 era aircraft.
A pic of a Vultee Veangence dive-bomber cockpit (http://community.webshots.com/photo/252490586/1252545484053545322SMiEqg).

kevjon

07-06-2006, 10:45 AM

I guess you just have to study your subject to detemine which is applicable, flush or slightly raised canopy framing.

Spinner

07-06-2006, 11:52 AM

Your's certainly dont seem to lack research and carefull study.

mrys

07-17-2006, 12:16 AM

I was experimented with Rhino mesher (Power Nurbs are good but expensive:() and found this:

620

Quads... in native Rhino 3 Mesher... Hmmm... And only 4350 polys....

kevjon

07-17-2006, 12:36 AM

With enough tweaking of the settings you can get reasonably good mesh in Rhino 3 on some sections of the aircraft. Where Rhino's mesher really struggles is on the leading and trailing edges of wings, tailplanes etc and the other area it is really poor is the joints between nurbs surfaces. Cleaning up the joints so it renders nicely and trying to break the mesh down into chunks for uv mapping is a time consuming process due to the messy mesher.

I guess it really comes down to what you consider good enough ! I'm a bit of a perfectionist when it comes to the final mesh. I like the aircraft to render nicely from all angles.

mrys

07-17-2006, 12:40 AM

I'm a bit of a perfectionist when it comes to the final mesh. I like the aircraft to render nicely from all angles.

So we are the same:D. Just discovered, that Rhino mesher screwed up my wings... Again, PowerNurbs are better at last. I will doubt no more:lol:

kevjon

07-17-2006, 1:46 AM

mrys

07-17-2006, 8:49 AM

We can only hope a great nurbs mesher comes along that will do a good as job as 3ds max's meshsmooth does with subd's.

Rhino is a great tool for aircraft & cars and definitely a quicker and more precise way to model mechanical objects than with subd's.

Agreed. I hope that possibility of mesher tool in Rhino will be improved. It understand quads - it is good news. But still after export mesh needs tweaking, sometimes as time consumed as making mesh from the beginning. So PowerNurbs rulez. Not perfect but the best understend Rhino surfaces. If only could do quads tweaking would be easier and maybe even we could join two methods: NURBS and Subdiv.

In my opinion decision about migrating with models from Rhino to Max for rendering has some consequences. Modellind process (in my case) have to be changed in some areas. Some elements I have to build another way then until now, to get best results after import to Max. But still it is quickest and most precise method for someone who is skilled in work with NURBS.

kevjon

07-17-2006, 10:50 AM

Full version of Powernurbs allows you to import *.3dm file straight into max and then convert to mesh. Is this how you are doing it ?

roshent

07-17-2006, 10:51 AM

Hmm... after reading these last posts I'm getting a feeling that you guys don't use the meshtool with the added options. And one other thing, Rhino has been able to make quad mesh since release 2, never owned v1 so can't comment on that. However wether it makes quads or tri's depends on the curvature angle that you build your surface with. Default is a 3° angle (I believe) if you change that to a lower degree you get not only a more detailed surface but also a better resulting mesh. This doesn't mean that the mesh tool can do wonders with regard to quads, as I'll hope 4 can, but it makes more quads as a result. One other little snag with those quads though. If you change the mesh Mrys showed above and use the polygon reduction tool, just give a number one polygon less then the actual the entire mesh will go into tri's. Since I used to use Rhino to make low poly meshes this was not always bad since most game-engines can't handle quad meshes. Therefore I don't have much experience to keep the mesh in a quad way, tri's were the goal I've strived for.

EDIT: forgot to mention that when you cut something out like in Mrys pic, you obviously get the same problem as with polygonmodellers, boolean hell tri's all over the place.

kevjon

07-17-2006, 11:09 AM

Posted by roshent
Hmm... after reading these last posts I'm getting a feeling that you guys don't use the meshtool with the added options.
What do you mean, the detail controls ? Of course I've used it and actually spent at least 16 hours trying every tutorial and every setting to get a good mesh from my Gloster Meteor. No luck I'm afraid !

Probably the best solution with Rhinos internal mesher is mesh each individual surface one at a time. Export to max and then try and weld it all together. Tedious stuff though that will quickly erode away the time saved by modelling with nurbs in the first place.

mrys

07-17-2006, 11:18 AM

Full version of Powernurbs allows you to import *.3dm file straight into max and then convert to mesh. Is this how you are doing it ?
Exactly. I'am in this happy situation, that my good friend has "Dtp and Advertisement Agency" and they working on Rhino and Max, so he had to buy many additional soft - Power Nurbs also. And I'am sitting sometimes in his office and trying before I decide to buy some by myself.

Roshent: It is a shame that I've discovered this just now, but I always tried to get not to much polys in my meshes but enough to get smooth results, and always get only tris. This time I decided to set all values to 0.00 and only one (has no Rhino in sight, so I dont remember exactly) to 0.05. I was sure, that I will get mesh with more polys then normal, but no - Rhino's behaviour was intelligent. My friend, when he looked this said: so, what? everyone knows that:cry:.

But still Result from PowerNurbs, even with tris is better.

Skyraider3D

07-17-2006, 11:36 AM

Great topic!
Note on the image with the three fuselage comparissons, how the PowerNURBS variant doesn't create smoothing errors around openings.

kevjon

07-17-2006, 11:47 AM

mrys

I have tried powernurbs to model with instead of Rhino but didn't find it as good. It is a very complicated piece of software. If enough time were devoted to it...most likely excellent results could be achieved. It does have plenty of great features though. One of them is the ability to go back and tweak your original curves and the nurbs surface updates to reflect the change. In Rhino you have to resurface and cut out all the booleans again or tweak knots on the surface.

giant551

07-17-2006, 11:58 AM

mrys

07-17-2006, 11:59 AM

mrys
I have tried powernurbs to model with instead of Rhino but didn't find it as good.

Oh no, I always model in Rhino and importing to max. Max has problems with its own NURBS, so I even did not try to do anything with imported NURBS;). I use max only for meshing and rest of process (rendering, texturing, lightning etc).

I admire peoples as Kiwi, Ronnie or Gareth, who are able to get such impressive results with subdiv., but for me NURBS are more friendly. Personally I'am not fan of Max as modeler, but think, that in some areas it is more effective then Rhino (in tanks I think).

BTW. Kevin, did you have any problems with PowerFillets in Rhino? I have:err:...

giant551

07-17-2006, 11:59 AM

mrys

07-17-2006, 12:02 PM

Well i'm still convinced that if you use Rhino Max is not the renderer to go for. I have had success with IGES with XSI. How does Max handle IGES could you not bring it in as IGES them mesh it in Max ??? I did this Export in literally 2 mins all i have to do if flip a couple of normals. Max seems alot of work for no gain for rhino:D

Unfortunatelly IGES in Max sux:lol:. Very poor results. Even with dedicated IGES export. Better results was with *.dwgexport, but in max are two kind of DWG importer. I don't remember good which, but one of them is useless.

kevjon

07-17-2006, 2:52 PM

Guys, I have never had problems getting my Rhino model into max either via the iges route or by using powernurbs to import the Rhino *.3dm model direct. Getting the Rhino nurbs model into max is the easy part for me and not really the issue.

It is converting the nurbs model to a good mesh that is the problem. Max's ability to convert a nurbs model to mesh is very poor particularily around the leading edges of cowlings, wings, fins and tailplanes. The mesh also ends up very low poly around curved surfaces and the joints in the nurbs surfaces don't weld. I don't think max can uvmap a nurbs model but if it can, I don't know how.

Giant, I'm glad to hear that it is easy for you to get your Rhino model into XSI. That is really great news for your old Rhino models and future work. I guess what I am interested in with regard to XSI is how good is XSI at converting a nurbs model to mesh ? Can you get a good clean mesh that renders flawlessly from all angles and is still easy enough to work with for breaking the mesh apart for uv mapping. When you have time I would be most interested to hear your results with XSI's mesher. Perhaps XSI can uv map a nurbs model so it doesn't have to be converted to a mesh ? I know you use uvmapper...but you still need to convert the nurbs model to a mesh so you can export to *.obj for that program.

mrys. I'm surprised your having a hard time with your Rhino models into max. Maybe your using a older or newer version than me which is causing you problems. I'm using max 7 and seems to work fine importing the two Rhino models I've tried. Sometimes it is best to import chunks of the model at a time rather than the whole lot in one go.

mrys

07-17-2006, 7:00 PM

Guys, I have never had problems getting my Rhino model into max either via the iges route or by using powernurbs to import the Rhino *.3dm model direct. Getting the Rhino nurbs model into max is the easy part for me and not really the issue.

It is converting the nurbs model to a good mesh that is the problem. Max's ability to convert a nurbs model to mesh is very poor particularily around the leading edges of cowlings, wings, fins and tailplanes. The mesh also ends up very low poly around curved surfaces and the joints in the nurbs surfaces don't weld. I don't think max can uvmap a nurbs model but if it can, I don't know how.
And here is the weakest part, I think. Max understanding of Rhino meshes is very poor. What is perfect in PovRay - smooth surfaces, ideal wing's and cowling's leading edges - becomes bad in Max. Unwelded points, duplicated edges, leaks. Maybe biger bug is in Max then in Rhino. I was noticed some cases, when even max could not read own *.3ds files! I had to resave them in other soft. But sometimes only max read it...

mrys. I'm surprised your having a hard time with your Rhino models into max. Maybe your using a older or newer version than me which is causing you problems. I'm using max 7 and seems to work fine importing the two Rhino models I've tried. Sometimes it is best to import chunks of the model at a time rather than the whole lot in one go.
Yes, I had some problems, but not to big. I think, that it could be fault of too complex surfaces build in rhino. I prefere import whole logical parts of plane (bottom part of wing for example) then whole planes. But also don't like parts exploded to smaller surfaces - in this cases tweaking was hard work. My last problem (solved now:D) was with it:

624

Big parts of wing just disappeared.

PS: we still talking about work with PowerNurbs of course

roshent

07-17-2006, 9:14 PM

It looks like flipped normals ?? Was that the case?, I never had anything not really there going into other programs...

mrys

07-17-2006, 10:41 PM

It looks like flipped normals ?? Was that the case?, I never had anything not really there going into other programs...

No, there were no flipped normals. The missing parts just dissapeared. They gone to the five dimensional universe, I suppose;).

Really don't know why this happened. I solved problem exploding wings into single surfaces before importing into the Max and untrimming some holes. But still it is a mystery. And sign, that even PowerNurbs are not perfect.

kevjon

07-17-2006, 10:58 PM

Posted by mrys
What is perfect in PovRay - smooth surfaces, ideal wing's and cowling's leading edges - becomes bad in Max. Unwelded points, duplicated edges, leaks. Maybe biger bug is in Max then in Rhino. I was noticed some cases, when even max could not read own *.3ds files! I had to resave them in other soft. But sometimes only max read it...
mrys, thanks for the update on your problems. I understand what you mean now. Frustrating stuff for sure. I haven't experienced dissappearing surfaces but certainly the other problems you describe I've come across.

Perhaps Rhino/XSI is the best combination of software rather than Rhino/Max ?

Or as Giant previously suggested Rhino/Brazil/Vray. Must look into this more , how much it costs and whether is will solve the uv mapping/mesh problems.

mrys

07-17-2006, 11:05 PM

I've noticed another strange Rhino behaviour. When surface is splitted or "booleaned" sometimes (not always) a copy of the surface is produced. Few times I was not able even to select this duplicated surface and delete it. After import by Max added surface appeared as part of its "parent". I suppose, that maybe that was reason of my problems...

kevjon

07-17-2006, 11:09 PM

Sounds like a Rhino bug.

giant551

07-18-2006, 12:12 PM

Well guys, forgive my ignorance but why do you need such a tidy mesh ??? It seems such alot of work for little gain ?? I do sort of understand that UV mapping a rhino mesh in Max can be a pain due to the fact you have to select poly's for mapping. That is the reason that most rhino users use UV mapper as there is no selecting of facets required (mostly) it will automatically split the mesh down the required plane you have selected:D

I have never had any problem with rendering out the rhino converted meshes i have mapped which would have most Max users diving for the valium !!!! And i have used this technique extensively not just for aircraft but for a lot of rhino models i have produced for work. These models have had reflective finishes and transparency's etc....and have had quite high resolution prints done from my flamingo renders. and more recently XSI:D

Its not perfect but it seems to work for me if i have to go back and use Rhino:D. This is my D520 i did a while ago using this method the mesh is far from pretty but it renders OK:D

http://i6.photobucket.com/albums/y248/giant551/uv4.jpg

http://i6.photobucket.com/albums/y248/giant551/uv1.jpg

http://i6.photobucket.com/albums/y248/giant551/uv3.jpg

http://i6.photobucket.com/albums/y248/giant551/uv2.jpg

I know i'm far from expert at 3D but this is (was) my work flow when using Rhino. :D I still use uv mapper for my XSI produced models as well. I hope it helps ???? Try and render a messy rhino mesh in Max and see what it looks like maybe ????

kevjon

07-19-2006, 12:42 AM

Posted by Giant
Well guys, forgive my ignorance but why do you need such a tidy mesh

As you can see breaking that mesh apart for uv mapping in max is a nightmare, so many little polys to select. Also I found that the rhino mesh does a poor job of the joints. eg between wing and wingtip which results in visible seams when rendering.

I'll look into uvmapper and how it might work for Rhino to max workflow.

What would be the workflow from Rhino to XSI or max ?
- Model in Rhino
- Convert nurbs to mesh in Rhino.
- Export mesh to uvmapper from Rhino via *.3ds ?
- Import uvmapped mesh into XSI or max via *.3ds.

Or is there a better way.

jiverson

07-19-2006, 4:19 AM

Hey Giant, I am also wondering about the uv mapper. Can you wrap it around the top or bottom of the fuselage or is it a straight on planar map? Just wondering if you get stretching in these areas.
thanks,
Jamie

mrys

07-19-2006, 5:05 AM

What would be the workflow from Rhino to XSI or max ?
- Model in Rhino
- Convert nurbs to mesh in Rhino.
- Export mesh to uvmapper from Rhino via *.3ds ?
- Import uvmapped mesh into XSI or max via *.3ds.

Or is there a better way.
Unfortunately UVMapper read and write only *.obj format, not *.3ds.
And I'am thinking, that (in case of max) it is better to:

- import into max by PowerNurbs,
- convert to mesh,
- export as *.obj,
- open in UVMapper,
- mapping,
- save model,
- open model in max.

kevjon

07-19-2006, 6:10 AM

Sounds good mrys.

I'll have to download uvmapper and give it a go. See how it works with a Rhino mesh and a max mesh. For $59US it sounds like good value provided the foreign file formats work ok with max.

mrys

07-19-2006, 8:14 AM

Yeah, I bought it month ago and I'am impressed with its possibility. Of course it can't do miracles, but solving overlaped polygons problem is worth of pay 60$.

Probably it is fault of set up, but after importing *.obj files back to max from uvmapper it lost smoothing. Fortunately auto smooth options in Max make good job here.:D

giant551

07-19-2006, 8:26 AM

There is a OBj importer plug in for Max i don't know if its any good ?? That could be an option ?? I export out of Rhino as obj into UV mapper then into XSI or back into Rhino.

This method is not perfect the main problem i have found with Rhino meshes is there very heavy in file size and can be a pain when imported into other applications. The viewport becomes really laggy:D

Jamie UV mapper can do cylindrical mapping also to get rid of the stretching. I have also mapped the facets from the top and bottom as seperate planar items before which works kinda well.

Anyway keep us informed Kev:D

giant551

07-19-2006, 8:30 AM

mrys

07-19-2006, 8:35 AM

kevjon

07-19-2006, 8:37 AM

I have just downloaded the trial version so, I'll give it a go both with one of my max sub'd models and my one and only Rhino model. It looks like a really good program.

mrys
There is a free plugin out there called max2obj. Might be worth exploring as it might do a better job than max's converter. I think it might be written for older versions of max but might still work with newer versions.

Skyraider3D

07-19-2006, 9:24 AM

What's wrong with MAX's unwrapping tools? :)

mrys

07-19-2006, 9:54 AM

What's wrong with MAX's unwrapping tools? :)

It is too easy way for really tough guys as me and Kevin:lol:.

But seriously, max unwrapping tools are very good, but personally I never feelt enough patient to use them. Now I'am in the moment, when I have to choose what soft will be using in next works. So I trying many different options.

giant551

07-19-2006, 12:19 PM

What I really hate in UVMapper is interactive rotating and moving gizmo. Small rottion and I have to wait for refresh, small rottion and I have to wait for refresh, small rottion and I have to wait for refresh, small rottion and I have to wait for refresh...

nd wht I REALLY HTE is my A key on my keybord. :err: It isn't work as should..

Thats one of the disadvantages of rhino meshes with UV mapper it makes the viewport really slow. It doesn't happen with polymodelled OBJ files:D

kevjon

07-19-2006, 12:20 PM

Posted by Skyraider
What's wrong with MAX's unwrapping tools?

Nothing is wrong with them but if I have to unwrap a really messy rhino mesh seems to me uv mapper is a far better option. Also looks like uvmapper has some good mesh relax utilities to help remove stretching and some other cool utilities that are not included in max. Currently it takes me about 5 hours to unwrap a aircraft in max. From what Giant has said uvmapper is far quicker than that. Thought it is worth a try.

Have you already tried this program and dislike it ?

kevjon

07-21-2006, 7:02 AM

mrys

I've never been able to figure out in Rhino how to set the construction plane to the z height that I want and and the angle I want and also have the setting applicable in all viewports. Is there a way ?
I find construction planes very hard to manipulate in Rhino but they are the best way to get things modelled where they need to be.

Do you use them much ? The help files are not very good and never been able to find tutorials about it.

Skyraider3D

07-21-2006, 8:56 AM

Until this thread I hadn't even heard of this program :D
I assume you've seen my animated mesh approach to UVmapping in MAX? That bypasses all slow updating problems you may have with dense meshes in the unwrapper. It's very fast too, give it a go.

pccdtk

08-14-2006, 11:50 PM

Unfortunately UVMapper read and write only *.obj format, not *.3ds.
And I'am thinking, that (in case of max) it is better to:

- import into max by PowerNurbs,
- convert to mesh,
- export as *.obj,
- open in UVMapper,
- mapping,
- save model,
- open model in max.

....I make a quick test with Power Nurbs and :

http://img162.imageshack.us/img162/4471/fouselagepf0.jpg

.....grey - Fiat CR32 fouselage export rhino to max as *.3ds ( best compromise between smothness and no.of polygons ) - ~ 11000 polygons
.....orange - Fiat CR32 fouselage export rhino to max with Power Nurbs ~ 6000 polygons

http://img226.imageshack.us/img226/8894/wingkv8.jpg

.....grey - Fiat CR32 wing export rhino to max as *.3ds ~ 3000 polygons ( best result using rhino mesh tools targeting 3000 polygons ) ...and orange - Fiat CR32 wing export rhino to max with Power Nurbs ~ 3000 polygons

Conclusion : Power Nurbs best software ( for that specific job , at least ) till now ....

kevjon

08-15-2006, 12:03 AM

Thats some nice nurbs modelling there pccdtk. Skyraider put me onto PN...glad its working out for you guys as well. Cant see much difference in the fuselage mesh but the wing looks much better as PN.

pccdtk

08-15-2006, 12:05 AM

For fouselage , I'm happy to obtain ~ same smothness with less polygons...

kevjon

08-15-2006, 12:36 AM

Yes that is one thing you images don't show and that is Powernurbs creates much cleaner nicer meshes that are easier to uvmap than Rhino's native meshes.

Skyraider3D

08-15-2006, 1:04 AM

Can we see some wires please?

How you guys getting on with the Quads option? It seems you can't get enough detail with it on... Odd...

pccdtk

08-15-2006, 1:36 AM

Can we see some wires please?

...of course:

http://img206.imageshack.us/img206/9779/snap1zh5.jpg

kevjon

08-15-2006, 1:53 AM

I don't think quads in PN is possible. The designers didn't think anybody would use this option so you always end up with tris.

Future versions may include it.

Nice mesh pccdtk..much improved over Rhinos.

pccdtk

08-15-2006, 1:56 AM

Skyraider3D

08-15-2006, 11:09 AM

There's a quads checkbox but it doesn't allow for much tweaking. I found collapsing to a patch and then poly creates nice quads, but with annoying double faces and mismatches here and there. Nothing that can's be easily fixed and it leaves a much nicer mesh.

kevjon

08-15-2006, 2:38 PM

Will give that a try....cause I don't like tri's.

Skyraider3D

08-15-2006, 3:00 PM

Me neither... chaotic mess :)

kiwi123

08-15-2006, 3:01 PM

Don't you have anything in Max that can turn Tris into Quads ?

kevjon

08-15-2006, 9:47 PM

Don't you have anything in Max that can turn Tris into Quads ?

Not that I know of.
XSI does have this feature though called quadrangulate which turns your tri mesh to nice quads.

Skyraider3D

08-15-2006, 9:51 PM

Now that would be a nice feature...

You can do auto-edge in MAX, which hides edges depending on the angle and usign small angles you can attempt to make quads. But that sucks a bit, really... Either way with these kind of NURBS tri-models you are never gonna become a nice quad mesh afterwards...

kiwi123

08-15-2006, 9:52 PM

LW has a nice script for it. Are you sure there isn't a script available ?

pccdtk

08-16-2006, 12:07 AM

I found this :

http://www.scriptspot.com/scripts/web_upload/Gene Crucean/quadrangulate.mzp

....litlle improvement...but is a start

vingrjoe

08-17-2006, 8:48 PM

This is an interesting thread for me because I'm using 3DMax7 and Rhino3.0 .
I model 3D ships for a hobby, and also use them to make animations for the Civ3 videogame. I use Rhino mainly for making hulls, then transform it into a mesh in Rhino, then export it to 3DS. I usually have to make the extreme bow seperately from the rest of the ship, and sometimes make it with two pieces. I use the "surface from a network of curves" function in Rhino from the hull station lines. A problem I come up with, is getting edges to match up smoothly. I have tried using the "match surface" command and to some success the "analyze surface" command to try to get better results. Here is an example of what I'm talking about. Any help or ideas would be much appreciated.

kevjon

08-17-2006, 10:39 PM

There is a command in Rhino called "join two naked edges" That is the best way I have found to stitch two surfaces together.
Analyze->Edge Tools -> Join 2 naked edges.

mrys

08-18-2006, 12:04 AM

Will give that a try....cause I don't like tri's.

For some (no all) surfaces exporting as *.dwg from Rhino and importing into Max could be useful. In most cases PowerNurbs give much better results, but *.dwg export is worth to try. In "Polygon Mesh Detailed Options" I give all values on 0, only "Maximum distance, edge to surface" on 0.01 or next best.

In this method you get meshes made of quads and tris.

kevjon

08-18-2006, 12:33 AM

It's interesting you had some success with *.dwg export. I had no luck on past attempts but will give it another go with the detailed options you've specified.

Skyraider3D

11-08-2006, 8:37 AM

A nice selection of NURBS tutorials:
http://www.maxforums.org/thread.aspx?tid=411318

Spinner

11-08-2006, 9:48 PM

MoI is getting better at nurbs export in obj form.
The latest beta has focussed on n-gons and quads.
If I understand things correctly, Michael is useing the same geometry libary as PowerNurbs, PowerBoolean etc in MoI.
I'm getting good meshes from MoI nurb creations in modo and max with his nov release. Only vertex requiring welding still an issue.
Since the beta is free I thought it worth mentioning.