Trying to loft a terrain: Fail.

# 1 12-12-2010 , 05:26 AM

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Hi all,

I'm trying to model a terrain from a series of topo lines I drew in CAD. I elevated them properly, I rebuild the curves to that they have the same amount of points, but some sections of the topo are giving me a hard time. They are folded on themselves, I guess because the CV's are not aligned (checked the curve direction, it's good.) I'm attaching a screenshot, anyone has ideas on how to fix this?

Thanks!

The problematic loft is the third one from the top...

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# 2 12-12-2010 , 06:30 AM

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I have had the same problem going from ACAD to Maya....I THINK (cant remember) in the newer ACAD you can triangulate a mesh.....I will do a check later for you. I too tried lofting from polylines but got the same result as you did. Will get back to you mate

cheers bullPS if you are trying to loft dont do all of the curves at once either...one at a time I found but it is painful if you have a lot of contours

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Last edited by bullet1968; 12-12-2010 at 06:31 AM. Reason: addenda

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# 3 13-12-2010 , 02:47 AM

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Hi mate,

well I exported a DXF from my Survey package of a project I am currently on...no pipe work (it is in another model). Maya didnt like the big file. I have it triangulated BEFORE I import...so if your CAD can create or interpolate a mesh it should come in just fine...the only thing I had to do was change the up direction to 'z' and not 'y' as Survey orientation is different.

So depending on which CAD program you use its possible. ACAD Im not sure if it can create meshes from points?? I know ACAD Land Desktop could map terrain and then export a mesh. Let me know what CAD program you used??

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bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

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# 4 13-12-2010 , 03:00 AM

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And you are selecting them in the correct order?

Environment Artist @ Plastic Piranha
www.joopson.com

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# 5 13-12-2010 , 04:08 AM

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Good point Joopson,

I couldnt find a triangulate points in ACAD...it can build surfaces etc but I couldnt get it to build correctly. Im sure there would be a way as the data I get for setout in the field is ususally done in ACAD.

sorry mate

bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

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# 6 14-12-2010 , 08:04 PM

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Here I have made 5 cv curves.

Notice:
1. all the start cv's (the boxes) are aligned.
2. all the curves have the same direction vector (the line from the box to the U shape)
3. all the curves have the same number of cv's
4. all the cv's are spaced uniformly

Before lofting each curve must be selected in order. Drag selecting will give unpredictable results.

and here is the loft:

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

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# 7 14-12-2010 , 09:30 PM

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Thanks ct...that is a help. I will point out however, that a complex terrain similar to what I do at work (see above) with multiple contours would take forever!! That image I posted is a small one and I could have cleaned it a little in civilcad (delete points (vertices)) but lose a little accuracy (depends what you want) has a total of 14 000 points....and thats just the contours! So linework would be intense and it would take you ages to loft all of that.

Here is the same image with contours only...the roads have 0.1 and 0.25m contours...the rest have 0.25 and 0.5m contours...and ALL of the polylines run in different directions (vectors) as when they design it, they dont care which way the lines go! so you can see doing something like an estate by lofting would be a right royal pain in the coight.

cheers bullet

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bullet1968

"A Darkness at Sethanon", a book I aspire to model some of the charcters and scenes

Last edited by bullet1968; 14-12-2010 at 09:36 PM. Reason: spelling

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# 8 17-12-2010 , 12:29 PM

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Short of writing a mel script or python data converter to organize large data sets there is no way to just dump huge amounts of curve data into maya and magically loft it. It has to meet all the conditions I listed and be selected in a specific order. This can be done, it just would require a way to logically parse the complex cad data and feed it to maya the way maya wants to see it.

You might want to check out creativecrash.com and see if there is a converter that exists.

"If I have seen further it is by standing on the shoulders of giants." Sir Isaac Newton, 1675

Last edited by ctbram; 17-12-2010 at 12:31 PM.

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