A scene I'm working on calls for chains, to hang lighting globes from. The scene is the Stone of Tear, from the WOT book, "The Dragon Reborn", by Robert Jordan of course. Here's a quick prototype, I'm doing some architectural research so don't mind the garbage-looking arches. Those will be re-modeled... But I need to make chains hanging the lights which obviously don't exist in this scene. I want to make GOOD chains, links that can actually be used in Maya with collision detection and gravity on so that they fall into place properly, and I'm wondering if anyone knows how to do this? Of course, I'll be exporting the chains to Bryce (Maya not only uses the .obj format, it's parent company is the one that created the format!) Anyone know how to go about such a thing?

Where is it ???:P I mean, you said prototype, I tought you gonna post some kind of image :D

Message edited on: 01/14/2005 02:06

Ha! Good call, thanks my friend...

Looking good, must be a bitch to render :P Looks like you have couple hundreds of pillars there !!! :D

Scene? I don' see no stinkin' scene! ;) Are these chains gonna be animated? I mean, if not you can whip out miles and miles of chain in the W proggie in no time flat.

oh.... that's better. ;)

Hmm... I don't use Wings, I use Whino. (elitism!) But neither Wings NOR Whino use anything remotely like collision detection, much less gravity. Perhaps I'll just take this question to the Maya forum, but there's not many users that stop by there... Mostly, I was wondering if anyone knew how to do it in KnotPlot, or if there was a free app anyone knew about to do such a thing?

Well, create an elipsoid curve and pipe it. Position your chain in a straight line and then flow links along a curve for deformation. It's not like you need concatenation curve, which pakled posted here a while ago. Unless I misunderstand the way the globes will be hanging.

-- erlik

No, no... I suppose that I should have specified. I have no problem at all modeling chain links, or positioning them by hand. That's easy for me. What I'm looking for is a dynamic way to make the chains realistic. Keywords : gravity, collision detection. I guess I'll just dive into Maya and see what happens...

I dunno. Seems like a lot of hassle for something that's just gonna hang there. Gotta applaud your thirst for knowledge though. :)

Glad to see you have gone back to scenes from the WOT. Is this going to be with Callandor there, or after? I had a go at the Dome at Far Madding, but never finished it, wasn't happy with it. Can't help with the chains, if I tried modelling a cube I would probably end up with a weird blob!

The greatest part of wisdom is learning to develop  the ineffable genius of extracting the "neither here nor there" out of any situation...."

Aye, I started the scene simply as a background for my version of Rand from Poser. Then I figured, since I've seen a dozen or so takes on the Heart of the Stone, that I would model it better and cooler than any of the ones I'd seen so far. Lemonjim drove me to it, his last scene was very nice (the one he turned into a QTVR) Here's a quick shot from Rhino. In Rhino, you'd use "sweep1" to make a chain link. Takes seconds, really.

And the finished solid... (just under 2K polys)

Message edited on: 01/14/2005 02:55

LDS you looking for chain like in the image i just posted. they were made in bryce using the torus i believe. i found this on a site which i don't have the link(scuse the pun) to anymore.

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(laughs!) Aye, those were made with a torus and cylinder boolean combination. Too RAM intensive, for the amount of chains I need. I suppose I'm just too damn picky, on this scene. Robert Jordan may be the best writer, ever. I just want to do him justice! I've got my chain link from Rhino into Maya, now. Which is stupid. Maya and Rhino model almost identically, I should have just made it in Maya to start with. And I'm running the dynamics on both gravity and collision... should be done in a bit...

blender has collision detecting but i supose its not elitist for ya??? :P

for some free stuff i made
and for almost daily fotos

(smirks at ysvry!) I didn't know Blender had collisions... Hopefully they work better than Poser 5's so-called collisions. I guess it's a perfectionism thing, I really dont' mean to be elitist about things. There's just a big difference in the way hand-positioned chains look, versus the way chains look in real life. And I am NOT going to hand-position thousands of chain links, I'm really just lazy and looking for a fast way to do it... Think I found it...

Here's a shot of the difference between orthogonal chains, obviously NOT hand-placed to meet, and the one-click, non-linear dynamic chains. Maya, still.

The links meet each other and slide a bit, rotate around their multiple axes based off of their mass, friction, and of course gravity... I had to turn bounce up to .1 so that they would all fall differently, which is the point of this whole thread... No two chain links ever fall identically against each other, in real life. Well, not round links, anyway. Cubical or flat lnks might fall identically... Here's three quick Maya renders. Kinda OT, but these will all end up in Bryce for rendering... First one is software rendered, middle is Mental Ray (draft), and the last is MR with Global Illumination (photon rendering + raytracing).

Um, I don't see a reason why you couldn't have posed the links in Rhino and then just applied flow along curve to get that slightly-relaxed look. Absolutely no need for collision detection. As far as I can see, of course.

-- erlik

Good point, Erlik. I'm merely striving for perfectionism, here... It's all up in the air, anyway. Maya doesn't export objects without some kind of plug-in, which I don't have. So I'll just stick to the Rhino-to-Bryce solution... I'm not quite ready to do the whole scene in Maya, although that might be cool... I don't know how to use Poser characters in Maya, at all... Also, to do a chain the length that I need in Maya, with this rigid body /gravity technique, would drive any PC to it's knees, and take as long to calculate as the scene probably will to render. I tried the calculation on 12 links and had to close down Maya after waiting half an hour with no response. I must not be doing it right!

Doesn't Maya supposedly have a built in modeler? (post #15)I'm all confused now...

Wings works easy for chain links too. Cut a torus in half, move 'em apart some. Bridge back together. They can then be manually positioned using bounding box and vertice selections.

---

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Did someone say Chains? Here's my Rhino Tutorial.

oh..well, my work here is done..;) Not sure what collision detection in rendering is (in networks, it's CSMA/CD and such..;). I'd just take a torus, grab half, pull hard on the major axis. Duplicate along the axis, rotate the dupe on that axis 90 degrees, and wash, rinse, repeat to taste..but that's me..;)

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Aye, Pakled, but a torus is a circle. A chain link is not necessarily circular! Indeed, you'd be hard-pressed to find any chain, anywhere, that is circular. Collision detection is when the polygons do not overlap, just like in real life. Bryce has nothing even remotely like collision detection, alas. If you move an object up against another object, they don't "bump" into each other. They just overlap. In real life, if you move two solid objects together, they cannot occupy the same space at the same time. They actually stop. This happens every time you touch anything, for example. Electroglyph, that's totally the way to go. Thank you very much! Should be a piece of cake, now...

*"Bryce has nothing even remotely like collision detection, alas."*

(laughs!) Close, Xenic. But it's not even remotely like collision detection. I'm very familiar with "Land to". It's just a pale, fake imitation. Not trying to point out Bryce's flaws. But they DO exist. And I'm starting to need other options in my work. Bryce's "Land to" option is mathematical, based off of positions. It's not based off of polygons, and doesn't detect anything like that. Even with terrains, it's just a shadow of what other apps do. Which is why you can't roll a sphere down a terrain, for example. Hopefully they'll work on that for version Six. Now back to my architectural slavery!