Complex Surface Model Editing

[rocksolid2]

Hi there

I'm looking for some help with a complex imported IGES model. It is basically a model of a bone in the finger of a human hand. It was imported as part of an assembly of a complete hand and each bone is separated into parts within the assembly.

Basically I want to 'shell' the bone leaving it hollow on the inside with a hole at each end of the bone to allow access into the hollowed area. Because it was imported as IGES it has approximately 300+ surfaces and I'm having difficulty in creating this shell effect. I've also tried to offset a surface from the original at 0mm and then subtract the imported surface away but there is a relationship between the two so this doesnt seem possible either.

Does anybody have any ideas with this one?

 

[SBaugh]

Make it a solid, then make another boss feature that is the shape you want the inside to look like (DO NOT Merge solids). Do a combine and subtract the second solid body from the first solid body.

Regards,

Scott Baugh, CSWP

http://www.3dvisiontech.com

http://www.scottjbaugh.com

faq731-376

 

[Luca83]

If im understanding your problem correctly...First i'd make it a solid, then id split the face on each end of the bone for your hole, then shell it, using the 2 split faces you created for your open ends.

 

[JNR]

I don't think that shell is what you are looking for if I understand your question correctly. I assume you want a SMALL hole in each end? This would be very difficult for the shell operation, particularly with the kind of surface topology you have in a bone. Shell requires that at least one face is open, so you would have to have a face the size of your hole. Thickness would probably have to be at least greater than 2X hole radius. The thickness/topology issues would probably give you error nightmares. I think the only way to do it with shelling would be to cut the bone in two with a planar cut (line sketch - through all for example). Then shell each half by using the flat face as the open face and merge the two halves back together. Then cut your two holes in the ends. Overall, I like Scott's method best.

If you bring it in as a surface model only, you might also get away with a surface thickening operation, but it also might fail depending again on surface complexity, radii, etc., as it would be thickened inwards.

Have you tried knitting surfaces, etc. to reduce the surface count?

Be naughty - save Santa a trip.

 

[Theophilus]

JNR,

Shell no longer requires an open face--check it out. Very useful feature sometimes. This allows the holes to be punched out after shelling.

However, depending on the original surfaces imported, shelling at a desired thickness may be a big problem. Often, thin shells are possible, while thicker shells omit faces and cause other computational problems. If this is the case, perhaps a simplification of the process can be done, such as making revolved cuts where the holes are needed where the holes open up inside the bone, but don't necessarily follow the outer surfaces precisely. Hard to tell what is ultimately required.

You may also be able to knit, offset, and cut with selected surfaces to obtain a mostly-shelled part.




Jeff Mowry
Industrial Designhaus, LLC

http://www.industrialdesignhaus.com

 

[JNR]

Ooooh..... I missed than one in 2004, thanks Theophilus. I'm only using it at home yet. We are not quite up on 2004 at work yet (SmarTeam compatibility! PDM is wonderful, but the more complex things get, the more problems arrise with revisions - oh well...)

Be naughty - save Santa a trip.