ctk111

I wasn't sure if I should be posting this in the VIZ or AutoCAD forum, but I figured I would get more hits here.

When I am importing a model with numerous curves I always seem to get a number of flipped normals. In CAD I model the general shape in 2d then I make it a region and finally extrude. In VIZ I try to unify the normals but that doesn't seem to work. I am doing this by selecting the object and then in the modifiers panel I selct normals then unify normals. I guess my questions are:

1. Should I be modelling differently in CAD so my normals are unified?

2. Are my steps to unify the normals in VIZ done incorrectly?

Thanks

JHalton

Yeah I had the same probs with Viz, in time I moved onto Max6 which now makes dxf's look like a 3 year old has drawn them. Not been able to correct this problem I now use exported Illustrator docs which look lovely. Illustrator has known problems not been able to open large dxf files so my solution to this was http://www.dwgconverter.com/ off on a tangent I know.

I know you are importing models. though this may be a useful piece of info for people.

Phew. I love the world of dxf dwg....to be continued, no doubt.

J

__________________
Just ask. You never know!

Tim Nelson

I model in autocad and file link to viz all the time without many problems. I think you can run into trouble when you start flipping faces, but it sounds like you are mostly solids modeling. Another thing to remember with faces though, is to always make them in a counter-clockwise order.

BUT, I wouldn't really worry about it that much, because in your material options in VIZ, all you have to do is check the box that says '2 sided material'. That will make all objects appear no matter which way your normals are facing. All your problems will disappear!

ctk111

Thanks for the posts.

Timmatron:
I'd forgotten about the check 2-sided material box. I can't look at my file to see if that's the problem until I get home. Hopefully that's it. What's up with making faces in a counter-clockwise order? I've never heard about this and is this in AutoCAD or VIZ?

If anyone can think of another possible solution I've overlooked to the flipped faces issue I would appreciate it.

Thanks

Tim Nelson

Here. In autocad, open up the help file. Go to the search tab and paste this in..."Draw Outward-Facing Surfaces and Remove Hidden Surfaces" then hit enter and should bring you to the topic that will explain the counterclockwise thing a little better.

Hope that helps

Mark Bolin

If you are using solid modeling in acad, make sure to UNCHECK unify normals when importing. You would think this should be on to unify normals, but the normals are already correct and this will only screw them up.

Good luck!

mark

illyrianeye

I have trouble with importing cad models into viz as well. I always get weird shadowy impressions on models for some reason.