How to scale one body part independent of others

[Gadget Girl]

So I think Poser is being very clever, and it's getting in my way. I'm trying to make a hybrid item for Harry. There is a waistband (for lack of a better term) that is conforming, so that it fits and stays with the morphs for the different Breeds. But then I have a drape attached to it, that is to be dynamic. I've added a special bone for the drape and that seems to be working fine.

But here's the issue. There is part of the drape that is closest to the waistband seems to be 'stuck' to the settings on the waistband. So when I try to scale the drape to make it fit the larger morph, that part doesn't scale at all.

So in the picture below, the waistband is the gold part and if you look at the drape you can see the bad stretching where the scaling doesn't take effect.

I've double checked the grouping, and everything is setup correctly. I tried editing the scale zones in the Joint Editor, but that seemed to make to so I couldn't scale anything at all. So what do I need to do so that I scale that body part independent of the rest?

(If your wondering, when I copy morphs, I get a similar distortion which is why I wanted to be able to start with some scaling and then adjust the morph from there).

 

[Gadget Girl]

I wish it never failed, but this time, right after posting the question, I figured out the answer. Of course, since I couldn't find the answer elsewhere when I searched online, I figured I'd keep this here for others. What I needed to adjust in the Joint Editor was the smooZ (not really sure what smooZ is, but it was the thing). I adjusted the HighEnd until it covered the whole area and it worked just fine.

 

[English Bob]

smooZ is joint smoothing, along the Z axis in this case (there's also smooX and smooY), which makes sense assuming that 'Arry's body is aligned along Z.

 

[Gadget Girl]

smooZ is joint smoothing, along the Z axis in this case (there's also smooX and smooY), which makes sense assuming that 'Arry's body is aligned along Z.

That makes sense. I didn't see a smooX and smooY but that's probably because of how it's laid out. I wasn't sure if it wasn't for smooth zone.

 

[Gadget Girl]

So not quite as figured out as I thought it was. It's true I was able to adjust things so that when I scaled the drape, the whole thing scaled, but in doing that, it starts scaling the other part on his Abdomen2, which I don't want.

In fact that's the whole reason I was trying to make this hybrid, so that I could break up the scaling between the two parts because the way Harry's girth changes with different morphs, doesn't quite equate to how his height changes.

It seems to be sort of all or nothing. If the front part of the drape scales, it scales the Abdomen2 with it. Any ideas?

 

[English Bob]

I'm having trouble envisaging what's going on here, not helped because I don't 'ave 'Arry the 'Orse. I'm assuming that his hierarchy goes something like hip - abdomen - abdomen2 - chest; is that correct? And which body part does your girth* conform to?

(*I know there isn't a saddle, but the equivalent part of heavy horse harness is also called a girth, so it seems like a reasonable name even if it's usually situated further forward.)

 

[Gadget Girl]

I'm having trouble envisaging what's going on here, not helped because I don't 'ave 'Arry the 'Orse. I'm assuming that his hierarchy goes something like hip - abdomen - abdomen2 - chest; is that correct? And which body part does your girth* conform to?

Yes, you've got the hierarchy correct. My girth is conformed to the abdomen2. The bone I created comes off the Abdomen2 and is called Drape.

I think part of the problem may be that I have an overlap in the geometry on purpose.

You can see that the drape covers the girth. So when I extend the smooZ is the joint editor so that the entire drape is included, it starts selecting the girth as well. I can't seem to find a way to select or unselect this except by using the dials for High End, High Start, etc. I can't seem to paint or select the vertices in any other way, or at least I haven't found it.

I've mostly been making changes in the Joint Editor with my customer Drape bone selected. When I try and make changes to the Abdomen2 in the Joint Editor, I always seem to end up being unable to scale the drape at all (meaning nothing happens when I turn the parameter dials).

 

[English Bob]

When you consider that I don't own the figure you're developing for, and that I have no experience of weight-mapped rigging, you should probably take what follows with a pinch of salt.

Harry's hierarchy extends along his Z axis starting from his hip forward to his chest. However the hierarchy of your caparison goes forward as far as abdomen2, and then doubles back on itself. I've not had success trying things like that in the past. That isn't the same as saying they're impossible, of course...

Having said that, the dynamic part of a hybrid should have no connection with the rest of the figure apart from the hierarchy definition and any welding that's needed. In other words, your abdomen2 actor should have no channels relating to the drape, and vice versa. I don't know of a way to achieve that in the setup room, which is not to say there isn't one, but I've chosen to do it by CR2 editing in the past.

Another possible problem I see is where the caparison doubles back over the girth, it looks as if the normals would have to change direction there, and that could cause artifacts when rendering.

If I was making something like this, my first approach would be to make it purely dynamic, with the girth being constrained. I may have missed something here.

Finally, if it is a caparison you're making (the covering that used to be worn by a knight's horse), Mrs. Bob says they don't work like that. They're effectively an extended saddle blanket, and there is no girth. The caparison extends under the saddle, and is held on by the saddle's girth.

Hope that helps more than it hinders!

 

[Gadget Girl]

Harry's hierarchy extends along his Z axis starting from his hip forward to his chest. However the hierarchy of your caparison goes forward as far as abdomen2, and then doubles back on itself. I've not had success trying things like that in the past. That isn't the same as saying they're impossible, of course...

Yes, I think that is exactly the problem. I may have found a way to fix it, although it will take some more experimenting to be sure. I was able to tell it to ignore scaling for the abdomen2, but scale with the chest. I seem to need scale smoothing with some part in order to be scaled at all, but since there is no geometry with the chest it seems to look fine.

Having said that, the dynamic part of a hybrid should have no connection with the rest of the figure apart from the hierarchy definition and any welding that's needed. In other words, your abdomen2 actor should have no channels relating to the drape, and vice versa. I don't know of a way to achieve that in the setup room, which is not to say there isn't one, but I've chosen to do it by CR2 editing in the past.

Interesting. I hadn't though to do that by hand CR2 editing. Yes, I agree, I want the dynamics to be independent. That's going to take some deeper learning of CR2s on my part, since I don't know much about the rigging side of a CR2.

If I was making something like this, my first approach would be to make it purely dynamic, with the girth being constrained. I may have missed something here.

Yes, that was my first thought too. The trouble I ran into, is that Harry has some extreme morphs like the Draft horse and the Beast, which seem to me are perfect options for this, but there's no easy way to adjust it to fit. See if I have it as one dynamic piece, when I start to scale in the Y to say match the height, the girth becomes so big it no longer touches Harry's stomach at all. I needed a way to scale them independently of each other.

Finally, if it is a caparison you're making (the covering that used to be worn by a knight's horse), Mrs. Bob says they don't work like that. They're effectively an extended saddle blanket, and there is no girth. The caparison extends under the saddle, and is held on by the saddle's girth.

Oh! Tell Mrs Bob thanks. It may be way easier to redesign slightly to build it that way. I was never able to find any reference images on how they are built, so I was doing my best to deconstruct for the images I could find. I do intend this to work with the Classic tack, and it does fit under the saddle. I know I could easily set up some constraints to hold it in place and get rid of the girth entirely. The front part of the caparison is fully dynamic and it wasn't to hard to make all the fitting morphs (all though I see I have some clean up to do).

 

[English Bob]

I hadn't though to do that by hand CR2 editing. Yes, I agree, I want the dynamics to be independent. That's going to take some deeper learning of CR2s on my part, since I don't know much about the rigging side of a CR2.

If you have an editor such as Dimension 3D's Poser File Editor, I can give you some pointers regarding what to look for. Let me know if you decide to take that route.

The trouble I ran into, is that Harry has some extreme morphs like the Draft horse and the Beast, which seem to me are perfect options for this, but there's no easy way to adjust it to fit. See if I have it as one dynamic piece, when I start to scale in the Y to say match the height, the girth becomes so big it no longer touches Harry's stomach at all. I needed a way to scale them independently of each other.

For a fully dynamic cloth, I'd start with something that fits the smallest morph you want to accomodate. Then you can apply each morph in turn, roughly scale the cloth so that it doesn't intersect, and re-drape it over an otherwise zero posed horse. Export each mesh to OBJ after you've draped it. Then your base mesh will be the one which fits the un-morphed Harry, and you can apply the other OBJs as morphs to that. Being fully dynamic, it should be fairly forgiving about fit anyway; you just want a starting point so the simulation doesn't have too much to cope with.

I was never able to find any reference images on how they are built, so I was doing my best to deconstruct for the images I could find.

I know what you mean: Mrs. Bob and I found plenty of pictures of horses in action wearing caparisons, but there's very little reference material. I was looking at a site last night, based in the UK, that made these things for the historical re-enactment market. Can I find it again? It's somehow avoided being in my history, and I can't seem to hit the exact search terms: I had to be creative to avoid lots of hits from Caparison Guitars. If I find it again I'll post here. I'll ask my daughter - she and her fiance do live action roleplay, as well as being horse people, and they might have contacts. Mrs Bob herself has contacts in the heavy horse world who might know where to look.

Meantime here are a couple of others that might be helpful if you haven't already seen them:
Making an adjustable caparison
Patterns

 

[Gadget Girl]

For a fully dynamic cloth, I'd start with something that fits the smallest morph you want to accomodate. Then you can apply each morph in turn, roughly scale the cloth so that it doesn't intersect, and re-drape it over an otherwise zero posed horse. Export each mesh to OBJ after you've draped it. Then your base mesh will be the one which fits the un-morphed Harry, and you can apply the other OBJs as morphs to that. Being fully dynamic, it should be fairly forgiving about fit anyway; you just want a starting point so the simulation doesn't have too much to cope with.

I've actually had bad luck trying to use a mesh that I exported out of Poser as the base, and the reapplying the original as a morph. The original mesh tends to break apart when I've tried that.

You're right though, for the most part dynamics are pretty forgiving of the fits. I'm only doing morphs for the extreme breeds, Draft, Beast, Shetland Pony, and Foal because all the others easily refit from Harry's base as soon as you run the cloth sim.

And thanks for the links. It didn't occur to me to look for an online pattern. Those are useful even though I've already struggled my way through most of the measurements. I did like the idea though of use tea balls to make guards for the eyes.