Orienting Faces in MAX

[Jeff Mottle]

I'll be the first to admit I am no MAX expert, but can anybody fill be in on the tricks to speeding up face orientation? Unify normals works about 5% of the time and picking each face manually is downright painfull. I guess I have been spoiled with Lightscape's Auto-Orient and Orientation blocks. I am doing a proof of concept report for some people in the company on implementing Ilustrate into our workflow for catalog illustrations, but the models are coming from our parent company. Apparently their modelers have never heard of the word "face normal" I have thousands of faces to flip on a very organic chair. Normals are all ove the place and there is no way to pick them easily. Ie. symetrically etc.

 

Thanks guys,

Jeff

[kid]

I know very little of how Illustrate handles a scene, but does it not recognise a 2-sided material? Making your materials 2-sided should help the rendering (but the model will still be a mess )

[Jeff Mottle]

I wish! Illustrate uses correct normals and smoothing to determine how it shades.

[TAKA]

Hey jeff. What i'm gonna say might sound stupid to u (i haven't really understood what u're after - ie, just flipping normals or something else). But u could do ur face orientation in LS and import it back in MAX.

 

:???: hope my idea wasn't that stupid (although it feels stupid)

[Jeff Mottle]

Thanks TAKA. No it doesn't sound stupid, but now I feel stupid. LOL! Why I didn't think of this, I'm not sure. Man I need to stop rendering furniture. It's killing brain cells. However I would still like to know what everyone else's approach to face orientation is MAX. Is there another alternative to manually flipping each face. I'm sure other Lightscape users will agree that MAX's face orientation is horrible.

 

Thanks TAKA, I'll do this when the real project comes in. I just spent most of my afternoon flipping faces and assigning smoothing groups. Sometimes when your face is so close ot the work, you need to stop, take a step back and look at the whole picture.

[nisus]

Hi Jeff,

 

I've hardly had any problems with normals in max as I don't import from any other applications. (Maybe I know why... ;-p) If some probs arised flipping normals/unify normals worked about 95% of the times.

 

I think I'm just lucky

 

rgds

 

nisus

[kid]

stuff I import from Rhino sometimes has normals errors. If a polysurface isn't water-tight (ie has an open seam or point) then the whole object goes haywire. I sometimes get it with ACIS solids exported from ACAD as dwg, it can be a perfect error free ACIS solid, but in the translation half the polygons can get flipped. It's not much fun.

[mbr]

I've had a few problems importing from Form-Z, but usually it works. I don't know Rhino or Lightscape, but in Form-Z you can triangulate the faces (adds polygons, of course) that helps sometimes. You can also export DXF files with the option to triangulate the faces. If that doesn't work it's on to the 2 sided approach, which has yet to fail.

[quizzy]

I only import polylines from Autocad, and have never had any problems with normals. If importing dxf-files be sure to weld on import and NOT to unify face normals on import. Strange thing however is that when a dxf is imported you should again weld all vertices... and adding a smooth modifier also could help.

[Jeff Mottle]

Thanks Quizzy,

 

Yeah I tried all of that, but this model is CRAP!! Seriously. Different resolution meshes all over the place, faces and edges that do not line up, you name it. If it could be done wrong this guy did it. As a result all of the "normal" things you would expect to work, don't. ;( The model was done in AutoCAD originally using meshes and face modeling. From about 20 feet away it looks awesome. Trying to use it in production is a nightmare. I have a ton more of these models coming in, and I'm starting to wonder if I will have to redo then all from scratch. I swear I have yet to see decent modeling from any other furniture manufacturer out there. It's so frustrating. Pay attention to normals people! Normals!!

[RomeoWill]

Hi Jeff, a little late I realize, but Autocad and 3d studio Max/Viz handle face normals completely different internally. To be frank-Autocad doesn't really place high priority on them (normals), while Max/Viz does. As such, whenever you model something in Autocad you must be careful not to mirror any part of the model as this will almost always guarantee flipped face normals, etc. Hope this helps.....

 

Regards,

[Jeff Mottle]

Hey RomeoWill,

 

Yeah I know the pitfalls of AutoCAD modeling VERY well. I've been modeling everything in AutoCAD for over 6 years. However the guy who actually modelled the chair had no idea what he/she was doing. I also posted to the MAX forum (Discreet) and it has become apparent that MAX/VIZ is no where neat the capabilities of Lightscape when it comes to face normal orientation. Such a shame.

[Ken Walton]

Is this furniture that you're modeling?

[Ken Walton]

Ok - after reading a little more thouroughly, I'm assuming that it is furniture you're having the probs with. First of all, lemme say welcome to the club. I've been on a huge project for the past three months, and made the mistake of trying to tackle it all alone. The problem now is the furniture - I need stuff that's as "up to par" as the building and unit detail. My production process has been: A) Try to get the models I need from various vendors and collections B) Purchase a few to discover that if you use them as is, they work fine - but if you need to change anything (even mats), you're stuck in the position you're in now. C) After reviewing "available" furniture, decide to model it myself D) Start modeling furniture in MAX before realizing that modeling this stuff in RHINO would be ten times easier because of their drawing tools E) Model good furniture, export to max F) End up with a billion (exaggerated...)polys from the IGES to get it clean, or a million from the 3ds export and run into the normals problem G) Decide not to kill myself or leave the country H) Give it one more final shot in MAX.

 

To summarize, I've found that if I'm doing the final production in MAX, it's best to have MAX models from the beginning - especially if you need to change materials or make slight geometry modifications. To keep my scenes neat and matlib open, I'll XREF the furniture and keep all of my deformers "alive" on the original scene - updating textures according to the scheme I'm using for my entire combined scene. I know that if you're new to max modeling, it can be different than what you're used to and appear to be an irrational solution - BUT - in my case, I've spent the extra time trying to fix other people's shit so I know that brushing up on max is the quicker of the two. ESPECIALLY if you're a perfectionist and desire the same quality of work filling the work you've done so far.

 

Ken Walton

[Jeff Mottle]

Honestly I consider double siding faces to be a very sloppy practice and avoid it if at all possible. There are some cases to use it but in 99.9% of my work I never doubl side a surface.

Also as this model is to be used with the Illustrate renderer the normals must be facing the right way as it needs the edges to be correctly oriented to properly generate correct outlines.

 

Originally posted by MrCAD:

well if you plan to render it in max or lightscape the best/fastest solution is to use 2-sided material to the objects u are facing problems of normals. It'll take to alot of time to change the orientations in max especially if its a complex model. The only problem I see here would be is when you export the file as .lp from max..Lightscape will not bounce of light from double sided faced objects..but there are work arounds.

 

hope this helps

 

MrCAD

[Jeff Mottle]

This is an very intesting idea. A couple of probelms ouside of those you mention. If there was a way to select normals that were not facing the camera this technique would be great as I could deleted them. I would however be left with a model that no longer contain whole elements so there would need to be some more cleanup. A great ide though that I may tery to explore further. I posted this same thread to the MAX forum and asked if it were possible to script a tool to flip normals based upon direction to the camera, but it seems that it is a fairly large task. If it was done in Lightscape, I wonder why is was not done in MAX. I can only guess that most do not import outside geometry so the masses do not need such a tool.

 

Originally posted by George:

Jeff, you've been on this project for a while now.

Here's a suggestion you could try.

Clone the model so you have two models with the same position co-ordinates. Select all the faces of the second model and flip them. Between the two models you now have all face normals outward. You should be able to keep your material single sided.

There are two draw backs to doing the models this way.

1.Your poly count will double.

2.Depending on the models your smoothing groups may not render properly, but I think it would be worth a try.

[Jeff Mottle]

Exactly, this is why I assume nobody else complains about this. Most must be re-creating the model in MAX or never dealing with outside models. For a tool that had been around for so long, it still amazes me that the normal orientation tools are so weak. This has been a beef of mine for a very long time.

 

Originally posted by Ken Walton:

 

To summarize, I've found that if I'm doing the final production in MAX, it's best to have MAX models from the beginning

[MrCAD]

well if you plan to render it in max or lightscape the best/fastest solution is to use 2-sided material to the objects u are facing problems of normals. It'll take to alot of time to change the orientations in max especially if its a complex model. The only problem I see here would be is when you export the file as .lp from max..Lightscape will not bounce of light from double sided faced objects..but there are work arounds.

 

hope this helps

 

MrCAD

[Spongebob]

Jeff,

 

I feel your pain.

 

When I first started using VIZ/MAX I modeled everything in AutoCAD seeing as it was all that I knew. Flipping all of the incorrect normals took as long to do as it did to model. Eventually I started using 2-sided materials until I could model more effectively in VIZ.

 

The only shortcut I found along the way was a 'flip normals' mode in the quad menu.

 

I know you're a smart guy and have probably already found this, but it was never mentioned so I thought it better to be safe than sorry.

 

Spongebob

Detroit, MI

[Jeff Mottle]

Thanks Spongebob,

 

Yeah I new about that, but it is very tedious and damn ner impossible when you have a very poor model with many small incorrectyl oriented faces. I was referred to a plugin at the ScriptSpot that performs face selection based upon camera angle, but of course does not discriminate againt the normal direction like Lightscape. My seach continues....r

[kid]

Most must be re-creating the model in MAX or never dealing with outside models

I got a simple looking dining chair from a company to do a visualisation render for them, the chair came to about 45,000 polygons. I was dumbfounded, for the life of me I could not see how 45,000 polygons could have been used. The model was a mess. They modelled it in rhino and a lot of the fillets were not properly done so there were many wrong faces, and double faces. I remodelled it in Max with just under 3000 polygons, using their chair as a guide.

 

I think where any real Max dedicated features are going to be used on the model, it is best to work with a model built in Max from scratch. That's just my little experience.

 

[ October 09, 2002, 08:35 AM: Message edited by: kid ]

[Dave Buchhofer]

Thinking on this real quick.. you can most likely use the tools in standard max editable poly to do this..

 

I'm thinking you can check the 'Ignore Backfacing' and then select all of the faces in your view.. then simply hide those.. switch to look from the other side.. and there is your faces that need to be flipped..

 

Might take a few passes, as i'm sure theres still some insanity that wont get caught, but it should at least simplify the process some..

[William Alexander]

Thinking on this real quick.. you can most likely use the tools in standard max editable poly to do this..

 

I'm thinking you can check the 'Ignore Backfacing' and then select all of the faces in your view.. then simply hide those.. switch to look from the other side.. and there is your faces that need to be flipped..

 

YUP!!!!!!!

 

Learned that one ADT to Viz3-AEC and frequently, extruded polys (crown molding). VIZ4 is practically flawless in this regard. No proplems with Max6 (no file linking) that I have seen. Max5, have never used, but may have similar problems to Viz3.

 

Hey did'nt I see a tutorial somewhere about this?

 

rgrds

WDA