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Animating A Swinging Chain?

PostPosted: Fri Dec 14, 2012 10:34 pm
by Epifire
Well simply put guys I am trying to make a animated chain with some ambient swinging going on. Thing is when I experimented with getting bones setup they were restricted to a one way axis and could not swing freely like a ball socket would in say, Hammer. Since I have not done any animations in XSI yet this is all new to me.

Basically I want to be able to move the bottom link in any direction I want and have the links above it since they would be linked together. Otherwise I see no other correct way of doing that.

Re: Animating A Swinging Chain?

PostPosted: Sun Dec 16, 2012 4:03 am
by kraid
A ragdoll chain maybe?

Re: Animating A Swinging Chain?

PostPosted: Sun Dec 16, 2012 5:41 am
by Epifire
kraid wrote:A ragdoll chain maybe?


Wait that totally makes moar sense, I think the whole idea of a rag doll chain just flew over my head on that one. Now how to make a rag doll chain.

Re: Animating A Swinging Chain?

PostPosted: Sun Dec 16, 2012 12:11 pm
by Mehis
You could use jigglebone to create the swinging effect. You wouldn't even have to animate the swinging, it's all controlled in the QC.

Re: Animating A Swinging Chain?

PostPosted: Sun Dec 16, 2012 4:46 pm
by Epifire
Mehis wrote:You could use jigglebone to create the swinging effect. You wouldn't even have to animate the swinging, it's all controlled in the QC.


A very light physics explosion could do the same in Hammer could it not? I am just wondering how to get that setup in XSI at the moment. Not sure how to make something a ragdoll prop.

Re: Animating A Swinging Chain?

PostPosted: Mon Dec 17, 2012 11:25 pm
by nub
I don't know if a jigglebone would simulate accurate movement from a chain. You'd probably get better results via a ragdoll chain. That would probably be much harder to do than a simple jigglebone. You should definitely try both methods if you can figure out how to do them. Unfortunately, I have basically no knowledge regarding rigging and weighing vertices and shit, so I can't help you with that.

Another possible alternative that's even easier (requires no models at all) is that you could try using rope entities and a custom chain texture, then do the classic "Source rope physics" setup in Hammer. The thing is, I don't know if the rope shader can support transparency, so a decent looking chain texture might not work out. Plus, it won't look as pretty as a ragdoll chain.

Are you trying to have players collide with the chains? Or is it purely for eye candy?

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 12:50 am
by Epifire
nub wrote:I don't know if a jigglebone would simulate accurate movement from a chain. You'd probably get better results via a ragdoll chain. That would probably be much harder to do than a simple jigglebone. You should definitely try both methods if you can figure out how to do them. Unfortunately, I have basically no knowledge regarding rigging and weighing vertices and shit, so I can't help you with that.

Another possible alternative that's even easier (requires no models at all) is that you could try using rope entities and a custom chain texture, then do the classic "Source rope physics" setup in Hammer. The thing is, I don't know if the rope shader can support transparency, so a decent looking chain texture might not work out. Plus, it won't look as pretty as a ragdoll chain.

Are you trying to have players collide with the chains? Or is it purely for eye candy?


Mostly eye candy but the player would have the chance to throw stuff at it and a rag doll would do well for that. Would kinda break the immersion to toss a box or fairly heavy object just to see it collide into a completely static chain. I think the only way I could see a static chain working well was if it was used for an area the player could not reach or if it was used to hoist something (like a old elevator or a very heavy object).

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 2:13 am
by nub
Ah, if you want players to interact with it, then the ragdoll method is the only one that will work. Ropes don't collide with props, nor do jiggle bones if I recall.

I imagine that the rigging and physics model will resemble that if a human spine. You could probably make a bone for every 2 or 3 chain links and it should look decent. I imagine that having each individual link move as a ragdoll would be very expensive to render.

Or maybe if you got really technical with how you weighed the vertices, you could make the chain sway realistically with only a few bones.


PS: Do you have Dishonored on PC? If you do, I'd recommend extracting the chain models from that game and looking at them in 3DS Max to see how Arkane Studios did it. It's an UE3 game so Umodel should be able to extract the files, then you can use ActorXImporter to get the models in to 3DS Max. I'm not sure if they used some feature exclusive to UE3 or if it's just basic ragdoll physics.

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 3:54 am
by Epifire
nub wrote:PS: Do you have Dishonored on PC? If you do, I'd recommend extracting the chain models from that game and looking at them in 3DS Max to see how Arkane Studios did it. It's an UE3 game so Umodel should be able to extract the files, then you can use ActorXImporter to get the models in to 3DS Max. I'm not sure if they used some feature exclusive to UE3 or if it's just basic ragdoll physics.


I got Dishonored, which is actually the game that made me want to make a dynamic chain so badly. Not sure about the whole decompiling thing though since I only use XSI and I am highly unfamiliar with Unreal Tools (although I do have them installed). I was getting the basics of bone chains when I tried bending them I noticed they would only bend on a single axis/plane in my test which led me to believe that may not be the correct method, or that I didn't have it enabled for that.

Still totally new to the idea of making a prop that uses movable parts.

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 3:58 am
by Gary
jigglebones only sway when their parent moves. They have some physics when it comes to momentum and gravity, but can not collide.

Cheapest and fastest solution is a rope with custom chain texture(the shader supports transparency), have it going from its start point to a small invisible physicsbox brush that is held by a phys ball socket. So if it's short enough the invisible box will get hit when you throw stuff/walk in to the chain. And it will move.

More expensive / more difficul / cooler(and better IMO) solution is the ragdoll one. Depending on the length/size and amount chain links, you should probably only rig every two or so links. And I'm pretty sure there is a way you could bound both ends of the chains to allow shit to be chained together(can't remember how I thought of doing it before).

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 4:03 pm
by Gary
You could decompile the wire/plug things in HL2EP2. Models are probably in "episode two content.gcf" and are under the name/directory "props_lab/power_cable* ".

Phys coll/hit boxes/bone weights/bones;
Image

It's just a ragdoll rope. You could just reskin it if you are feeling lazy :P

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 6:59 pm
by Dr. Delta
I think it would be similar in XSI, this is how you would do it in 3ds max:


Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 7:14 pm
by MayheM
I am sorry, I can not help it...

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 8:00 pm
by Mehis
Gary wrote:jigglebones only sway when their parent moves.


Weird, I got my own custom rope moving without the parent moving at all.

Re: Animating A Swinging Chain?

PostPosted: Tue Dec 18, 2012 11:02 pm
by Gary
Mehis wrote:
Gary wrote:jigglebones only sway when their parent moves.


Weird, I got my own custom rope moving without the parent moving at all.


You have no non-jigglebone bones? Huh. That was assumption, I guess it was a wrong one! Thanks for the correction.