Polygons to shelled solid

inspired by old memory of bird bone to try something. went amazingly well. actual time spent was maybe an hour.

(only thing there)

Excellent. Are any othere IDers using polys for modeling now that you can convert to nurbs? I am interested in poly/sub divs for modelling organic surfaces

dont know anyone. but this has been discussed before. earlier i didnt understand subD that well. probably the reason my early conversion efforts failed. i’ve read up and think i understand it now. helps both the conversion and controlling the form it yields.

i’m seeing this as a fast concept method. maybe.i made another part. vaselike. shelled it too. did a draft check which was pretty good. went to “0” and "negative only on the p/l. CNC would ignore and cut to plane. also went and modified the NURBs surfaces and it still imported to Pro/E cleanly.

theres some awesome polygon/subD modelers out there. low cost. dont know about convertors tho. Maya’s does a really nice job. i was thinking of tiles. could make a graphic. map that as displacement to a NURBs plane. convert it all to polygons. then go back to NURBs with the graphic as 3D. into Pro as a cut surface and i’m golden.

too many cool things out there.

I was discussing this with a computer artist and a graphics computer programmer today. The answer I received is that actually going from polygons to surfaces doesn’t mathmatically work. Meshes, though they look right a mere aproximations of where the surface would be. Surfaces (at least CAD surfaces) are a much more precise form of math and graphics computation. That is why it is easy to go from surfaces to polygons, but not the other way.

I am sure that I over simplified what I heard, but 3D graphical math is not exactly my expertise.

i fully understand the mathematical issues. not everything requires y=x+1 precision. most surfacing operations dont - splines arent precise. they’re excellent approximations. just like an stl tooling file.

updated the site with a new part. picture worth a thousand words.

little update. hoping to get back to the “holes” version. didnt. have posted a couple shots. one proe no big deal. was pretty happy with the “gore” shot tho! no subsurface scattering (ie no Mental Ray). just regular shader/renderer. didnt post the “hole” version. will do that in a moment. at least can see what the form is.

agree with ykh -hull based curves are approximations anyway- you tweak till it looks correct visually. If you use Alias in any free form manner whatso ever then poly to subdiv is a very viable solution

came across a nice site other day. really nice overview of the math. shows the hulls and explains the approximations. i hated math during engineering. all i thought about was ID. now i enjoy it more.

plus just found a Formula script for Maya (the resources for that program are amazing - highend3d.com is always full of updates). that and my Super-Ellipsoid plug-in should give me some wild forms. will have to do a polygon test using those.

on that subject, I saw a job posting recently of a toy diecasting(model cars) company looking for modelers for sub-d model some cars and I guess export them to *.stl after.
I guess that sub-d modeling saves a lot on time and some companies are catching on.

my recomendation for a sub-d program, a very nice little tool called SILO (www.silo3d.com) for under a 100$ and a very small learning curve (master it in 2weeks probably) check it out.

Anyone checked out Rhino’s new tools (i think it’s a plug-in) that converts mesh to nurbs?