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# 1 24-05-2003 , 08:18 AM
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Birail Error Message ?

Hello friends !

Well, I´m testing the birail tool again - and I think it´s really wonderfull, cause there are sooo many possibilities.

But now I have again a little problem. If I want to use the birail 3+ tool, I get the follwoing error message:

// Error: mpBirailSrf3 (Mp Birail Srf Node): birail surface computation failed //
// Warning: You have an empty result since history is on. You may want to undo the last command. //
// Result: multiProfileBirailSurface3 mpBirailSrf3 //
// Error: mpBirailSrf3 (Mp Birail Srf Node): birail surface computation failed //

Hmm, I don´t know what I did wrong, or what I can do to avoid this error.


Here is a little image from my simply ep-curves:
user added image

and here is the maya file:
https://www.tophunter.at/3dproblems/spitfire.rar

Thx for every little help,
bernhard

# 2 24-05-2003 , 09:12 AM
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Hello Bernhard

At first when I saw your screenshot I thought that rail curve was one continous curve, but close inspection yields you have your two rails and the profiles, all connected.

I did notice all your curves where having diferent spans, I rebuild them all to cope with the pointers I told you in the other thread (Opossing curves need to have the same spans remember?) and yet again it did not compute the results.

So I think the only solution as of now for your predicament is to birail the surfaces one by one. That´s the way I obtained the surface you see in the screenshot. To achieve it instead of going around picking all the profiles, just pick two profile curves and then the rail ones, and on and on. You can also use Birail2 for this.

Resulting surface is not a very pretty one, but you could rebuild and stitch afterwards.

On a little side note: You wouldn´t even imagine how many resources that big ass grid of yours is eating mate. Stop fiddling with the preferences and viewports. Almost crashed my machine. user added image

Hope this helps,

Attached Images
# 3 24-05-2003 , 10:28 AM
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birail

Hello adldesigner and thank you very much for your help - that´s really fantastic.

My english isn´t really good, so sometimes there are many things I don´t really understand.

okay, below you can see a image, that describes some questions I have. I´m really not sure, if I understand definitly what the opossing curves are, and the spans ?

If this will fit in my little monkey brain, I hope I can build up the ep-curves as they should be --> consider your lections:

1. Opossing Curves should always have the same spans.
2. Opossing Curves should always have the same direction.

user added image

puuuhhh, it´s not really easy with me .... user added image


thank you soo much for your help,
bernhard

# 4 24-05-2003 , 02:33 PM
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(on ur image, top down)
a span is the distance between 2 CV's

yes theyre the two opposing curves, they shud contain the same number of CVs in roughly the same place

both profiles shud have the same number of CVs as well

the direction, you can reverse the direction of the curve in one of the nurbs menus, cant remember which, sorry

opposing curves are just like ur two rails, they shud have the same number of CVs, and ur profile curves, i wud just define them as the same type of curve


- Simon

My Website: www.Glass-Prison.com
# 5 24-05-2003 , 05:23 PM
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You're going to want to take the CVs into account rather then EPs.

# 6 24-05-2003 , 09:19 PM
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Hello Bernhard

The opposing curves in the image you supplied are exactly the ones you noted, same case would be the two rail ones.
Remember at the end, Nurbs surfaces are just four-sided patches so there´s not much point at which you can get lost with them.

As per your question regarding spans, it would mean it needs more points, yes. Since spans and editpoints actually converge in the same point in space you can pretty much predict where will the span fall by watching at Edit Points. To change the spans the best way of doing so would be, going into the Attribute Editor, noting the spans of the curves, go into Rebuild Curve and rebuild it keeping the ends, but specifying the new set of spans. That should take care of it quickly and without mess.

Direction can be noted in Nurbs curves by watching the litte U-icon in the curve and it´s relationship to the little cube one. Direction of the curve will go straight from the cube to the U to the end of the curve. It´s called U direction in curves.

On a little side note @Mike: Why should he take CVs into account for spans, since they don´t match up, and can be subject to confussion.
I mean it because if you didn´t have a way of checking the spans in the Attribute Editor, I could pretty easily trick you into thinking there are more or less spans by looking at CVs. -CV view does not show what degree the curve is, only the CVs, thus to know spans by looking at CVs you´d need the degree info of the curve right?-
That´s why I still believe he could look at EP info to know how many spans there are. (although truth to be told I would check in the Attribute Editor just like you)

Attached Images

Last edited by adldesigner; 24-05-2003 at 09:34 PM.
# 7 25-05-2003 , 10:17 AM
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Now I understand !!!

Hello adldesigner !

Thank you again for your wonderful support - that´s really fine, and also thanks to all other user in this forum for helping me, like mike. :banana:

Now I understand why it´s important to have the same spans from opossing curves, and how I can get it. And I also know how I can get the same direction.

I fulfilled your very important two lections in my example.
But now I was very surprised - why ?

1. I´ve created the first surface with birail 2. Very well, all okay. I´ve got the follwing UV SPANS 1/4

2. After that, I created the 2nd surface with birail 2.
And here I´ve got a surface with the follwoing UV SPANS 5/4.


Is that okay ? user added image


user added image



thx for helping me and best wishes,
Bernhard

# 8 25-05-2003 , 01:52 PM
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Wondering

Hello friends !

I thought I will post you the image of my result working with the birail 2.

Well, I´ve tested it and wanted to see if there are some distortions on the mesh. Hmm, I´ve attached surface by surface and this is the result.

user added image

I wonder, cause I think the mesh is really without any distortions or something else. I´ve converted the nurbs-->SubDiv

and than the SubDiv to a PolyObject - well, that´s the result.

hmm, so, I don´t know if the little example is modelled right with the birail 2 tool, because there are some strange things I don´t understand --> I mean the different UV Spans in the Surface by creating nurbs surface with the birail 2 tool.

thx,
bernhard

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