Modelling it "the right way"

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Modelling it "the right way"

Postby Torf » Tue Aug 23, 2005 10:37 pm

Hi guys!

After my bottle of coke, I want to advance to something more difficult, so I'm now trying to model a fork. I'm afraid I still didn't get the "way" you model using splines (opposed to the way you model with meshes). You can see how I started in the attachement "screen01.jpg". Problem with this approach: After extruding the model, I get all those orange-square-marked points, which are, according to the manual, usually a bad sign (screen02.jpg).

So how would one do this "the right way"?

Thanks for your help!
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Postby sascha » Tue Aug 23, 2005 11:34 pm

Orange squares are not necessarily a bad sign - it's just a warning; Patches most likely won't connect smoothly there (with a few exceptions). In case of a "polygon like" model, they're inevitable.

If you are happy with a poly-look of the fork then there's nothing wrong with the orange dots.
If you want a smooth fork with round spikes you could use the Lathe tool (4 segments!) to create the spikes and connect them to the "body" using 5-point patches:
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Postby Torf » Wed Aug 24, 2005 8:23 am

Ah, ok. Thanks for the explanation. Your model sure looks more like one would expect a patch model to look...

Just took another look at my fork (the real one :D), and I now think that the main problem with it is it's mixture of being straight and round. It's straight on the faces, but the edges are rounded. A mixture of your and my model, I guess. I'll take another try at it when I come home today.
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Postby sascha » Wed Aug 24, 2005 9:48 am

If your shape is mostly smooth, I would model it as if it was entirely smooth and set some points to "peak" afterwards. Note that you can toggle peak/round per curve segment (you can selet the segment using the TAB key).

I do not recommend modeling with the "peak" mode turned on as you won't be able to see how the splines are connected - and eventually end up with some weird mesh (you can witness the mess by making everything round again).

JPatch is not good at all for poly-style modeling - although it's possible, it's quite cumbersome. It is meant for modeling and animating "organic" shapes - all those kind of things that are virtually impossible to do with e.g. POV-SDL.

Note that it is still possible to use non-jpatch models in the Animator. All you need is a POV-Ray or RIB file of your model. Then make a JPatch model that roughly resembles your external model, but clear all patches (so nothing will be exported to the renderer - this model will just serve as a visual representation in the Animator). Load this "dummy" model into the Animator, select it and click on the Edit button. You can now enter arbitrary POV or RIB code, e.g. an "#include <mymodel.inc>" (POV) or a readArchive (RIB) directive.

Haven't really tried it, but this should work :wink: .
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Postby dcuny » Wed Aug 24, 2005 8:58 pm

Along those lines, here's an excellent tutorial on how to attach fingers to hands without a lot of creasing. Here's a comparison between the two:

Image

Here's what the final mesh looks like. The tutorial takes you step by step through the process.

Image

It's a bit more complex than "normal" spline modeling, but the results are cleaner. Of course, you won't really see the difference until you start doing animation with bones... :?
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Postby sascha » Thu Aug 25, 2005 6:38 am

Thanks David, the tutorial is truly excellent. A nice example of how to use hooks and five-point patches to prevent creases. Looks like it's written for Animation:Master, but it should be applicable to JPatch as well.
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Postby Torf » Thu Aug 25, 2005 7:38 am

Thanks for that link, I'll go throught it tonight. Didn't even think about searching for A:M tutorials. Only found some sPatch/Hamapatch ones. Good idea :)
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Postby kl » Thu Aug 25, 2005 5:54 pm

5 point patch is great, is it possible to have 6 points patch?
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Postby sascha » Fri Aug 26, 2005 8:08 am

5 point patch is great, is it possible to have 6 points patch?

Well, yes - it wouldn't be that much work to add support for it. On the other hand, I'm not sure if its really needed. Until now, I was able to create all topologies using 5-point patches.
The only topology I found that would require a 6-sided patch is shown below - but it can easily be approximated using two 5-sided patches (connected to the rest of the model with two hooks):
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Postby Torf » Sat Aug 27, 2005 2:21 pm

The tutorial is really great. Here's what I made of it and another one: It looks ugly like hell and nowhere near the one on my left arm, but hey: That's my first hand ever modeled :wink:
I focused on getting the splines and patches right (without creases). I think I did a fairly good job (pretty easy following those tutorials), but I'd like to hear what you got to say about it (especially about how the thumb is attached).

Have a nice weekend everybody, BTW!
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Postby sascha » Sat Aug 27, 2005 3:39 pm

Looks good, nice job! From what I can see it seems to be free of creases.

PS: I've found out that arms or legs can be modeled quite realistically using only 8-point loops (for toon style 4-point loops can be sufficient as well). You can use hooks to limit the boundary loop of the hand to 8 points (where it would connect to the lower arm).

PPS: Some excellent free A:M models can be found here (yes, I'll add this link to the Wiki ;-) )
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Postby kl » Sun Aug 28, 2005 3:06 am

sascha wrote:
5 point patch is great, is it possible to have 6 points patch?

Well, yes - it wouldn't be that much work to add support for it. On the other hand, I'm not sure if its really needed. Until now, I was able to create all topologies using 5-point patches.
The only topology I found that would require a 6-sided patch is shown below - but it can easily be approximated using two 5-sided patches (connected to the rest of the model with two hooks):


maybe my method was wrong, when I was modeling my hand, I somehow created four 6-sided patches between the fingers.
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