It occurred to me, looking at Maveris' body chains in the RDNA store, that dynamic cloth ought to work to make flexible chains. Any of the cloth masters given any thought to that? I'm not terribly persuaded by the EasyPose chains I've seen, but when I think about dynamic chains, the first thing that comes to mind is a growing list of challenges. How to make the links solid and only the junctions flexible, for example. Has anyone seen chains used this way? M

Hmmm... Dynamic chains would be interesting to see. Perhaps a dynamic chains/ropes system. Don't know if it would be easy though, and I kind of doubt you could "piggyback" it onto dynamic cloth. The physics involved is too different (soft body dynamics for cloth vs. rigid bodies with many collisions to detect for chains.) Seems like it would need its own "engine" along the lines of the dynamic cloth or dynamic hair engines that was dedicated to this type of simulation. - Jimdoria ~@>@

Problem with dynamic chains is that the minks go thru each other. If one object breaks the "plain" of another object then collision doesn't work in the cloth room. The objects in quetion just slide thru each other. A dynamic ROPE might work and be textured to look something like a chain tho. mike

This was discussed on another forum, but not put into practice as far as I know. It was supposed that you might be able to apply transparency and displacement maps to a long thin strip of "cloth", and simulate that; but it wouldn't be good for big links since they'd be visibly deformed. Might be usable for fine, jewellery type chains though. The Poser Physics add-on might be able to do this.

I downloaded a dynamic string of pearls from freestuff recently which works extremely well, but I have not looked at its structure to see how it is done.

Attached Link: http://forum.daz3d.com/viewtopic.php?t=31921

Just checked, the item is "Dynamic pearl necklaces" by Stegy

Just loaded the necklace and had a look at it in the cloth room. It is a narrow strip of dynamic cloth with beads strung onto it,and the beads are set as a soft decorated group.

It MIGHT be possible to do a similar thing for chains (I've been toying with the idea myself, but havn't got round to it yet..)
A thin strip of cloth (made totally transparent) + a set of chain links made "rigid decorated" set into it.

Would be rather poly-heavy, though.

Cheers,
Diolma
Edited to add: Trav: the problem with doing rope in the cloth room is that a tube (to carry the texture) collapses into something flat (like an empty fire-hose). I've tried it, and couldn't get it to work convincingly. Of course that may well be due to my own deficiencies.. Cheers, Diolma

Message edited on: 03/14/2006 15:49

How to make a tube keep its shape in dynamic cloth simulations? - Make a small one-sided strip, this will be the dynamic group; - Surround the small strip by a tube with approximately the same polygon size. This will be the soft decorated group. Should work! By the way, chains and PoserPhysics can do some very nice things. PoserPhysics will do the rigid body dynamics. Hmm. How would PoserPhysics and dynamic cloth play together? Time for some experiments, I guess.

Oooh! Please do experiment, Steven!

Trying to get a catenary curve on a chain (even one with "smart-pose") is a real PITA!

Cheers,
Diolma
Edited to add: The best I ever achieved was to use the cloth room to calculate the curve; used a long strip of cloth attached at each end to a cube, moved the cubes towards each other at frame 20 and calculated. Then I exported the strip as .obj, and attached the chain-links manually in a modelling app, using the strip as a guide... Tedious..

Message edited on: 03/15/2006 15:29

Been trying out some ideas but the big problem is how to select the correct polygons in the cloth room for the different groups. Poser is really bad in this respect.

dadt: I think you can select and assign material groups when using the cloth-room grouping tool. Try assigning different materials to the various bits, then selecting those materials in the cloth room?? The Pose-room grouping tool is easier to use than the cloth-room's one (IMHO). Or do the applying in a modelling app or UVMapper... Cheers, Diolma

I had different materials applied when modelling but the cloth room doesn't recognise them.

Drat!! Now I've got to try to work out how I did it before! ('cos I did..) dadt: Are you using P5 or P6 (there may be a difference there..)? Are the materials "groups" within a single object? Just trying to narrow down the possibilities... And, I regret, I can't reply further tonight, it's WAAY past my bedtime! Cheers, Diolma (It CAN be done, but I forget how)...

Using P6 and the materials are applied in Wings 3D.

When you have the group editor up, click on the Add Material... button. Then select your predetermined material, and that will be added to the current group - in this case, the soft decorated group.

Why didn't I notice that button before? Thanks EnglishBob.

Wow, that's a better result than I might have hoped for. This opens up all kinds of possibilities - must find the time to experiment with it.

Now, I find that impressive, dadt! Which did you use for the links? Soft or Rigid decorated? (and a note of gratitude to EnglishBob for reminding me about the "Add Material" button - I couldn't remember what that button was called when I was typing my post...) Cheers, Diolma

The links are in the soft decorated group, other settings are:- fold resistance 1 shear resistance 1000 stretch resistance 1000 cloth density .015

Thx, dadt. Are you going to try a version using Rigid Decorated? Might help with the distortion at the more extreme bends.. Or have you already tried that and found it doesn't work? Just curious... Cheers, Diolma

Tried it with wierd results

Not too surprising, but maybe if you increased the fold resistance it would increase the bend radius to the point where the links would stay together? I've seen weird stuff happening in the cloth room preview while simulating clothes, but it generally seems to sort itself out at the end.

Errm.. dadt, are you using the latest SRs for Poser 6? I used to get that wierd stuff in the cloth room too, but after installing SR2(?) it seemed to go away. Of course, it may have been something else that I did right without realising it.. All-in-all, I think I'd personally prefer to go with the rigid-decorated method. Easier to fix using post-work:-)) I also agree with E-Bob, fold resistance might work... I'm so glad you're working with this! I haven't had the chance to get to grips with it, been a little tied up (or should that be chained up?) lately.. Cheers, Diolma

Cool stuff, dadt... I'll have to have another look at my dynamic whip and play a little with your settings as a starting point. Maybe it will behave more like a whip during a real animation :D

The problem with increasing fold resistance is that when the chain hangs over the chair arm it curves out before dropping vertical and looks completely wrong. I don't usually have the problems with the cloth room and I just tried a different chain model which did not show the odd distortions during the draping.

Nice work, dadt. You've progressed further than I did. If you'd like some low-poly chains for further experiments, mine are only 18 polys per link. They look surprisingly good in close-ups, with a nice reflection map and some P6 polygon-smoothing.

Thanks, but I just make them as required in W1ngs 3D,only takes a couple of minutes,

That looks awesome, dadt! :)

Quote - This was discussed on another forum, but not put into practice as far as I know. It was supposed that you might be able to apply transparency and displacement maps to a long thin strip of "cloth", and simulate that; but it wouldn't be good for big links since they'd be visibly deformed. Might be usable for fine, jewellery type chains though. The Poser Physics add-on might be able to do this.

Hmm.. it occurs to me that taking your chain object and laying it right on top a cloth plane would be the way to go here.  Export the result to an obj file with the figure names checked and then reimport to a blank scene.

In the cloth room, specify the cloth plane as regular old dynamic cloth, put the chain portion into the soft decorated group and then drape.

Might take some adjusting to get the parameters right, but that would probably do the trick.

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