Help exporting topo info as a surface for 3D

[uagman]

I've been pulling my hair out, and just found this forum, so hopefully my hair will be saved...

I have a client-supplied AutoCAD file for 3D topography information. I am a 3D animator working in Maya and I need to create this ground surface from this file. I have the great translation software PolyTrans by Okino to import into Maya, but Maya unfortunately has no easy way to create a surface from this data.

How can I get this data into Maya as a 3D surface and not a million line segments? Can AutoCAD export as a surface? Or is there another program that can act as a go-between? I also have VizR2, but never learned to use it well. Viz, however, seems to crash when I try to import the dwg.

Any pointers would be greatly appreciated, as time is ticking on the deadline. Thanks!

[fuccaro]

Hello Uagman!
From AutoCAD you can export as 3DS and DXF. Can Maya import any of those formats?

[CADTutor]

It does depend on what type of height data you have. If you have contour data and those contours are AutoCAD polylines, you're in luck. You can use these in VIZ 2 to create a terrain model and then export that to Maya. This tutorial, http://www.cadtutor.net/dd/studio/terrain/terrain.html tells you how to create a terrain model in VIZ 2 using AutoCAD contour data.

[uagman]

Hello Uagman!
From AutoCAD you can export as 3DS and DXF. Can Maya import any of those formats?
Yes, both. Do you mean that AutoCAD can export a solid surface as those formats? I have been able to read their files, which included dxf, but since the file was not a surface, Maya was not able to create a surface from it. Maya - best animation software, worst CAD importer ever.


It does depend on what type of height data you have. If you have contour data and those contours are AutoCAD polylines, you're in luck. You can use these in VIZ 2 to create a terrain model and then export that to Maya. This tutorial, http://www.cadtutor.net/dd/studio/terrain/terrain.html tells you how to create a terrain model in VIZ 2 using AutoCAD contour data.

I will try the VIZ tutorial - thank you! Not sure if I have polylines, but I can find out. It also depends on VIZ reading the file in successfully without getting stuck at 98%...

Thank you both for the suggestions!

[fuccaro]

Uagman
I must admit that I am a bit confused. As I know, exporting a surface from AutoCAD you will got a surface in DXF format. Also in 3DS.
Do you start in AutoCAD from a surface? or are those just lines?
If you have the coords you can use them to (re-)create a 3dmesh (surface) in AutoCAD.

[uagman]

The AutoCAD file appears to be just lines in 3D space. What is the process for turning that into a 3D mesh in AutoCAD so it can be exported as a surface? (Please excuse my zero knowledge of AutoCAD)

[fuccaro]

Without seeing the drawing it is hard to tell you the best way.
If you have in AutoCAD a set of short lines arranged like a net, you may use EDGESURF to create a small surface. You will have to create small surfaces to cover all the net. For sure you can union together all those surfaces in Maya.
A better way: count the number of vertexes in booth of directions (let’s say your net is 50x40 in size). Set the OSNAP to ENDPOINT. Use the 3DMESH command, enter the number of vertexes and than click in order, line after line all the points. After clicking the last one the mesh will appear on the screen. If you are beginner you should practice first on a small net.
Also it is possible to write a Lisp routine to create the mesh starting from the drawing or from the file containing the co-ordinates

[uagman]

After looking at your suggestion, I realized that it would take much longer to familiarize myself with AutoCAD and try these suggestions than I had. So I got creative.

I determined that the original file was way to big to import into VIZ, as it kept crashing it. But the tutorial worked wonders with a smaller file. So, I went into AutoCAD, split the file physically down the middle and created two separate files, and successfully imported them into VIZ and created the terrain.

For those who may be interested in specifics, on the occasion that there is another Maya animator out there struggling with the same issue:

• Make sure the original CAD file is only around 10MB or less
• If it isn't, use AutoCAD or whatever software originated the file to save the file out in pieces
• Save the file as an AutoCAD .DWG R14
• Import into VIZ
• Use the Terrain function (as seen in the tutorial http://www.cadtutor.net/dd/studio/terrain/terrain.html )
• Export as a .STL file (works better than 3DS or DXF ultimately)
• Use Okino PolyTrans to import into Maya - regular Maya import sucks
• Ta-daaa! Save the file, do the same to the other pieces, and combine the files when done.

Hopefully that will save someone the tremendous time it took me to figure it all out. It really shouldn't be that hard, and maybe I missed something easy. But this workflow actually worked.

Thank you fuccaro and Mr. CAD Tutor for your help!

[gcp310]

i did read that if you saveas a DWG down to a DXF v12 or 13, it will convert solids to surfaces. Maybe worth a try, i know its not a solid.

G