More surface modeling questions

SW 2005

I have been trying to get up to speed on surface modeling the last couple of days. I'm making good progress thanks to the suggestions this group has offered.

Let me restate the problem and see if anyone has any ideas: I am importing a 'point cloud' iges file. It is a 3d scan of a surface of an automobile. It comes in as more than 500 faces that make up the surface. There are holes in the surface and jagged edges. I can delete these ragged faces and fill them in later. When the surface comes in, it is not associated with any coordinate system. I can move it around using Insert, Surface, Move/Copy. What I would like to do is take some of these faces and associate them coincident to the standard planes on which I could then draw sketches to set fill boundaries. Since this is just a part file, I can not use mates to associate the faces with planes. Is there an equivalent way to do this 'mating' in a part file? I realize I can create new refernce planes to sketch on but I would like to use the standared planes if I can.

Reply to
Mark
Loading thread data ...

Mark,

I will be interested to hear how your efforts turn out. My experience is that SolidWorks doesn't really handle this type situation (the import of scan data) very well. Nonetheless, you may know some things that I don't.

Unfortunately, you can't use mates within the context of a part to reposition the imported geometry relative to your standard coordinate system. You have apparently already used the move/copy functionality and been unhappy with the result. Have you considered putting your import part into an assembly, mating it as desired with the standard planes in the assembly, and then creating a copy in a new part file with standard planes that correspond with those of the assembly? This approach may seem a little complex, but it might accomplish your goal and result in an easily edited part file.

Reply to
John Eric Voltin

Mark,

Jeezis, you're doing it the hard way. I'd jump off a bridge before going through all that. Is there any real requirement or is this just your idea? I'd recommend you forget about the coordinate system and planes altogether. Don't make sketches on planes. Complete waste of time. Use 3D sketches to connect vertices with lines and do fills or lofts. Curve through reference points would be even faster if SW could use them for fills, but the curve entities can only be used by lofts.

Good luck.

Matt

"Mark" wrote in news:_Avee.512$ snipped-for-privacy@bignews3.bellsouth.net:

Reply to
matt

I posted an image of my progress on this part on my web site. Click on the Solidworks page:

formatting link
I know some of you are going to have a hoot when you see how many steps I went through to do this. I will take some of the posted advice to try streamline it. Mark

Reply to
Mark

I don't have access to that scanning equipment or the vehicle as I am still interviewing for the job. If I get the job, I will be learning to use the 3d scanning equipment, I think. The manager I am interviewing with told me the guy who supplied the iges data intentially moved the surfaces from the original coordinates to test the job applicant (me). It threw me off because I like to have everything pretty well locked down before I start messing with it. I'm learning that this surface modeling is more 'arts and crafts' than the familiar solid modeling. No liner edges to work from. Mark

Reply to
Mark

OT comment: Nice RV-4 project, Mark. Looks like you cornered the market on Cleco clamps :)

Reply to
Art Woodbury

Mark,

From this, and your last post, I'm assuming that moving the scanned point cloud and resulting surfs to a "normal" plane within SW is the "test". But it sure would be a lot easier for you to download a trial copy of Rhino, import the surfs, move to the desired location, and export to SW. I do this sometimes when I get an IGES file and/or a parasolid file that doesn't orient the way I visualize it. BTW, keep in mind that SW is a Y up modeler and Rhino is a Z up modeler. I'd be happy to do it in Rhino for you, but I would assume that that would not be part of your test.

HTH, Muggs

Reply to
Muggs

VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX VXVXVXVXVXVXVXVXVXVXVX

Reply to
dog peter gnat

Thanks Muggs, but I was able to accomplish my task by creating reference planes on a couple of flat surfaces, then deleting the jagged surface elements, then drawing 3d sketches coincident to the new planes and filling to those sketches. I then thickened the surface to make the part. I did pull the imported surface around a bit using Insert, Surface, Move but I still don't know if there is a way to hook it to the standard planes. One interesting thing about this exercise was how my computer choked on the part. The iges file was 19 MB and it created a SW part of 195 MB! My computer with 500 MB ram could not handle it. I used Rhino to whittle it down to a small chunk and pulled it back into Solidworks. One odd thing was that the surface would only thicken to 0.070". I wanted 0.080" but it would not go. I wonder how to diagnose this problem. The only thing I could figure was it must have encountered self intersecting geometry when I tried to go to 0.080". Any ideas on this? And another thing, in Rhino, how would you relocate the surfaces to a coordinate system? Is it just by eyeball, or what. Mark

Reply to
Mark

Mark,

I don't know how the iges files were created, but you had said that is was made from scan data. Some scanning packages create iges "surfaces" by basically taking an STL and putting a single surface between the three legs of each and every triangle. So needless to say that makes for a VERY large file and can typically become non-manifold. If it were done in Raindrop Geomagic then the surfaces could be as good or as bad as the person creating the surfaces in Geo. Which makes me think, when you say that there are "holes" in the surfaces, that not very much time was spent in Geo to do a nice job.

Jon, I have purposely stayed out of the c.c.soildworks VS Jon & Cliff debate, but if you think that you can use one and only one software package to do all that is needed to "get the job done" then you have once again shown your hand. And before you tag me. Yes I have downloaded VX and found it to be cumbersome. But maybe it's just me. One thing I think we all tend to forget is that some software packages just "fit" some peeps better that others. I have been using MasterCam since version 3 (It was called Clear-Cut then), but I have a very good friend that swears by Delcam. Go figure!

Anyway, my 2 cents, Muggs

Reply to
Muggs

formatting link

Reply to
Jeff Howard

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.