CGTalk - Need help with Physique envelopes

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valoukh

07-03-2005, 04:49 PM

Hi there! I could do with some advice. I am skinning my character Biped with Physique and I've encountered a problem. Please have a look at the following screenshot:

http://img214.imageshack.us/img214/1985/env6pw.jpg

Figure 1 shows the arm in its default pose. However, as I rotate the arm upwards (Figure 2), it is becoming deformed. Now, I have played around with the envelopes literally for hours on end, but I cannot seem to get the arm to work properly. I think the problem is that I can't get the envelopes in the right place to sit snugly with the shape of the arm. At first, I convined myself that I was having these problems because my model is a non-standard shape (i.e. the shoulders are rounded and the arm isn't where it would be on a human), but soon realised that this is a silly thing to think: lots of animated characters have very strange shaped bodies). So basically I am asking for some advice! Where should the envelope go? On Figure 3, the green line represents what I see as the start of the arm. The fact that it's at this angle worrys me, but human arms don't stop at the body - they join at the collar bones.

When I was using Softimage XSI, I could basically assign individual vertices to each bone. In this situation I could probably just set up a diagonal line, alike to that in Figure 3, so that the arm knew where to stop. I think, therefore, that my problem is with the envelope interface; it doesn't seem very versatile and can't work out how to position it right.

Any advice would be very welcome as it feels like I have come to a dead end.

Thanks,
-valoukh

marktsang

07-03-2005, 05:10 PM

simple use skin instead of physique - you can weight verts and paint verts you dont have to use envelopes but you can..... ect...

mark

valoukh

07-03-2005, 05:35 PM

Oh!

I tried using Skin but it looked exactly the same. From what you said, however, it seems that you don't have to use envelopes... sounds good to me.

Just to make sure, please have a look at the screenshot of my biped (below - I've changed a lot since the previous screenshots). If you (or anyone) can see any reason why it would cause problems please don't hesitate to tell me! If, in your opinion, it looks fine and should be okay for skinning, I'll go right ahead and use Skin.

http://img25.imageshack.us/img25/7654/env28iy.jpg

Thanks very much,
valoukh

valoukh

07-03-2005, 05:43 PM

One other thing: when using Skin, what bones would you add? Do you add all bones from the biped, or do you leave some out like, say, the COM?

Thank you!
valoukh

valoukh

07-04-2005, 09:45 AM

I think I'm getting the hang of this! I think it's going to take me a looong time, but it's going alright so far. The hip joint and shoulders are horrible to envelope, but I'm sure I'll get them done eventually.

Thanks a lot for the reccomendation marktsang, Skin truly is superior to Physique! It seems that Physique is only really good for very standard, uniform, human characters. You must have to be a genious to use envelopes on a non-standard character; to me they just don't seem to offer as much flexibility as Skin.

Thanks again,
valoukh

grury

07-04-2005, 05:14 PM

a easy fix for that would be to use skin weight verts and then apply a skin morph mod on top of that..it does a great job at creating bulges and fixing any overlapping mesh..

good luck

Bao2

07-04-2005, 05:59 PM

Also be sure to take a look on the Skin Morph Modifier to correct your mesh in very ample bone angles.

valoukh

07-04-2005, 08:02 PM

Am I anywhere near on target with these Envelopes? I know they are very uniform but I'm having trouble making them more 'organic'.

http://img301.imageshack.us/img301/4510/weights1xx.jpg

Thanks,
-valoukh

JHaywood

07-04-2005, 09:09 PM

There's a script called SkinOrDie that I've heard good things about, but haven't tried myself. It supposedly lets you change the shape of the envelopes, more like Physique. But by default, the envelopes in Skin will always be that pill shape. I've been able to work with it that way it is though, so never felt a need to try SkinOrDie, but look it up at scriptspot.com and see if it helps you.

Always, about your question regarding which bones to add, you only need the actuall bones you'll be weighting the verts to. You don't need the nubs, like with Physique, or the COM object.

grury

07-04-2005, 09:10 PM

I wouldnt worry so much about envelopes, would instead start playing with the vertice weights and get a nice blend between the two bones.

valoukh

07-13-2005, 10:42 AM

Well, when I wrote Envelopes I actually meant Vertex Weights...my mistake! My main problem is that I'm imagining one thing in my head, and something different is happening on screen. I.e. I'm doing exactly what I imagine should give me the results I desire:

1) Resizing/repositioning envelopes.
2) Assigning Vertex Weights to create an even blend between high-influence and no-influence areas, ensuring that some vital areas get a little bit of influence (such as the hips).
3) Adding Joint gizmos at relevant places like, for example, the knees.

However, these steps lead me to a point where, after keyframing my joints, I'm getting a lot of "crushing", at, for example, the area where the leg joins the body, and at the ankles, and so on. It's very frustrating, as it doesn't seem like it should be this difficult! I feel like a bit of an idiot really.

Where would you put your joint deformers? I assumed they just went in areas like the knees, elbows, and so on. Would you put them anywhere else, say, the upper or lower legs? I tried this just to see if worked (and was therefore likely as the next step), but it was twisted at an odd angle and deformed severely and was seemingly irreparable.

I'd much appreciate any more tips as I feel like I have a thousand questions regarding this field to which I am comparatively new and have had a lot of trouble finding good tutorials Thanks for your help so far!

-valoukh

grury

07-20-2005, 12:35 PM

Have you tried the skin Morph Mod on top of your Skin? Guess that would fix a lot of those issues, without having to bang your head trying to get the perfect blend.

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