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Carmel
05-08-2010, 05:10 PM
Yesterday I tried converting some models of furniture from .dwg format to .lwo. I used 'Deep Exploration' to do the translation. They came through, but in pretty bad shape. Lot's of normals were flipped and the polygon tessellation was horrible. Have people found that .dwg models are difficult to convert? Is it the format, or was it actually the models? Thanks.

archijam
05-09-2010, 03:15 AM
depends how they were created.
A few points:
- Autocad ignores normals. Therefore many flipped polys were provalby just modelled that way.
- acad has 'regions', their version of n-gons, polys with any number of verticies. Many apps just ignore or triangulate these.
- a polyline with height in acad comes into 3ds as an extruded line, in all other apps as ignored or a line...
- there is little or no control over edge sharing, ie you will always have to merge your points.


Best to edit first in acad, or use a detriangulation, merge and align function in lw.

MicroMouse
05-09-2010, 02:09 PM
AutoCad does double sided rendering and there is no way for the technician to build the model without having flipped polygons.

All the drawing entities such as line, polyline, circle, etc. are independent of the other drawing entities so vertices always have to be merged.

Some software such as Sketchup and Chief Architect appear to have no flipped normals when converting a DWG file and this is because they save out double polygons with the surface normals flipped for every polygon in the model.

Wayne

Carmel
05-09-2010, 06:06 PM
All the drawing entities such as line, polyline, circle, etc. are independent of the other drawing entities so vertices always have to be merged.

"Merging" is an understatement. I also have to do welding, mending, and remodeling. It's a mess. Fortunately, it's not important that these models look nice. So I'm not going to spend much time fussing with them.

Thanks for the responses guys.

prometheus
05-10-2010, 01:37 AM
what format did you export out to?

I use deep exploration daily to import solidworks prt,sldasm files and then
export to lightwave, but I do not export out to lwo directly, Im using obj format wich keeps data more intact and have more options to choose from.

My suggestion would be to export to obj instead to see if that works better.
in deep exploration under tools/3d tools you can make poly doublesided or invert faces.

In lightwave you can use the Align command, Align might be a hidden tool, in that case, go to edit menus and search for align polygons and add it manually.

Michael

prometheus
05-10-2010, 01:39 AM
"Merging" is an understatement. I also have to do welding, mending, and remodeling. It's a mess. Fortunately, it's not important that these models look nice. So I'm not going to spend much time fussing with them.

Thanks for the responses guys.

yeah itīs a mess here to with doing welding, remodeling of sit cushions, resurfacing etc...some models are around 600 000 polys, not that easy to work with in lightwave open gl.

Michael

biliousfrog
05-10-2010, 04:09 AM
Download the Rhino demo and try that...I found the results much better when converting DWG models although they will still be messy. At least you can interactively adjust the tesselation of the nurbs surfaces before exporting. I did come up with a pipeline but it was a while ago now and I can't remember it...I seem to recall a lot of tweaking in ACAD before I even got the file, it wasn't a great workflow at all.

-EsHrA-
05-10-2010, 04:34 AM
http://lx-viewer.sourceforge.net/


mlon