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hdace
08-25-2008, 12:30 AM
This feels like a dumb question for me because I've been successfully modeling humans and organic objects generally for several years without any agonizing over this sort of thing. I'm doing my first car and I don't think I'm very good at it yet. I've read the tutorial on this site carefully but newer cars seem to have issues.

I've created the round part of the fender that goes around the wheel and the headlamp separately to get their shapes perfect. All I want to do is put one or two polys between them but doing so always distorts the nice shapes of the previous geometry and no amount of jiggling around points gets the shapes back to where they should be.

I've tried adjusting the SubPatch Weights but that doesn't really help much either. Is there some trick I'm missing? I try using extend (e) and welding and just clicking on the original points and hitting p with virtually the same results.

Any advice appreciated. Thanks, Hal

meshpig
08-25-2008, 01:27 AM
Try not just one extend but 3 0r 4+, usually the curve you imagine is right but it needs more on either side to correct...

-Probably because you don't encounter hard edges in the human form?

m:)

hrgiger
08-25-2008, 07:05 AM
I've created the round part of the fender that goes around the wheel and the headlamp separately to get their shapes perfect. All I want to do is put one or two polys between them but doing so always distorts the nice shapes of the previous geometry and no amount of jiggling around points gets the shapes back to where they should be.

I've tried adjusting the SubPatch Weights but that doesn't really help much either. Is there some trick I'm missing? I try using extend (e) and welding and just clicking on the original points and hitting p with virtually the same results.

Any advice appreciated. Thanks, Hal

It sounds like you're not understanding how subpatch works. I assume you're using subpatches, correct? Also, it always helps to show a screenshot, preferably with a before and after adding the polygons.

Subpatching is subdividing your polygons and smoothing them at the same time. When you add geometry like you are, you're lessening the curvature(or smoothing) between your points which is having the effect of forming a tighter curve which is why it's distorting your original shape. You need to plan for the placement of your geometry when you are modeling to get the shapes you are after. When you add geometry to an existing mesh, the closer you add that to another edge, the more of a crease that you are going to get.

You can get some more information about subpatch modeling and the effect of adding geometry here: http://www.lightwiki.com/Fundamentals_of_Subpatch_Modeling_Part_Two
I would look at some different pages while you are there as well.

hdace
08-31-2008, 05:23 PM
Probably because you don't encounter hard edges in the human form?

Quite.

hdace
08-31-2008, 05:31 PM
When you add geometry to an existing mesh, the closer you add that to another edge, the more of a crease that you are going to get.

I'm glad you mentioned that. I intuitively knew it but sometimes it's really helpful to state an axiom clearly just to remind someone how to work.

But the rest of the stuff you mention I of course already knew from modeling organic objects.

No, the 'trick' I was looking for was something that I've very rarely used previously which is why I couldn't remember it. I knew there was something... and it was to use freeze and then build 'faces' geometry around it (instead of subpatch). Whenever I need something nice and curvy and smooth I use subpatch temporarily, freeze it when I'm done, then revert to unsubpatched face polys instead. If you keep the poly count a little higher and more detailed than one might do when using subpatches, one really can't tell the difference. The car's looking terrific now, BTW.

Cheers, Hal

Surrealist.
09-01-2008, 12:39 AM
You might want to also take a look at my tutorial. I go into some of these "axioms" if you will. Something that might help with your further understanding.