Cloth & Newton Dynamics

[jason1025]

Hi Folks

 

 

I have been studying Cloth and Newton Dynamics. I have been very productive results and am amazed at the power behind both of them. I have a puzzle I am trying to solve. For a few short shots in my presentation I have a parachute carrying some cargo to the surface. I was thinking because the cargo is very heavy and large that instead of cables connecting the cargo to the parachute I would use chains. I have been practicing creating chains with Newton and its very easy and works great. You get a huge payoff for little effort. Another reason why I want to use chains is they are visually stimulating more so than newton driven cables. I am not apposed to cables or a combination of chains and cables. Maybe cables connected to the cloth but chains connected to the cargo so at some point cables and chains are connected.

 

My dilemma is that I cant figure out how to connect the two. The cloth to the chains.I would assume that a force of wind would be driving the cloth as well as the force of gravity and momentum of the adjoining chains. The chains would be constrained some how to the cloth and the newton dynamics would make the chain react to the cloth and cargo.

 

First problem I encountered is that you can run Newton and Cloth sim at the same time. Maybe that would be a good feature request. Lets say that is not a problem. You can get away with simulating cloth first and newton 2nd. I tried that but it didnt work. I constrained the links to the cloth with offsets but when I simulated newton the newton chains eject into outer space. So even though you give a newton object a translate constraint it does not seem to adhere.

 

 

Any ideas or thoughts. I may be going about this all wrong. I am open to suggestions or ideas.

[robcat2075]

An all cloth solution might be to make the lines to the parachute out of cloth. Long, thin cylinders. I'd been thinking of trying such a thing.

 

Possibly after you had that simulated you could use the new attaching constraint to attach chains to the mesh of the lines and then hide the lines. If you have to have chains.

[jason1025]

Thanks for the suggestion. I dont see where the "new attached constraint" is located

[robcat2075]

"Group"

 

I've never tried it. It attaches a bone to a group of CPs.

[HomeSlice]

I've never tried the "Group" constraint either, but here is the description:

"With the Group Constraint, it is possible to attach a Group from one model in a Choreography to a Bone from a different model. The constraint needs to be created from the bone of interest. Then, using the Target property, you can select the named group from another model which is to be constrained to this bone. "

 

 

Another possibility might be Custom Cloth Groups.

Custom Cloth Groups are covered in the Cloth Tutorial here:

http://www.hash.com/forums/index.php?showtopic=29731

Page 8, "Custom Cloth Groups"

[robcat2075]

I've never tried the "Group" constraint either, but here is the description:

"With the Group Constraint, it is possible to attach a Group from one model in a Choreography to a Bone from a different model. The constraint needs to be created from the bone of interest. Then, using the Target property, you can select the named group from another model which is to be constrained to this bone. "

 

Hmmm, that's different than I thought. I guess I can't use that for attaching a button to cloth.

[jason1025]

Still having trouble

[robcat2075]

Still having trouble

 

can you show a test?

[jason1025]

Here is a model.

 

I cant come up with a solution

Parachute021.mdl

[robcat2075]

The cloth material isn't part of the model so I can't really test it out.

 

But have you tried an all cloth model as a test? All cloth, no Newton. Not chains, cloth ropes.

[jason1025]

The cloth material isn't part of the model so I can't really test it out.

 

But have you tried an all cloth model as a test? All cloth, no Newton. Not chains, cloth ropes.

 

I tried an all cloth version. didnt work

 

 

cloth.mat

[robcat2075]

My Dharma donut keeps falling out of the parachute but this is the general concept of what I was thinking of.

 

DonutDropH.mov

 

ParachuteTest_03b_simmed.zip

 

 

Everything is cloth. Even the donut.

[jason1025]

Thats impressive. Did you use a force to give lift?

[robcat2075]

Thats impressive. Did you use a force to give lift?

 

no, "air drag" slows the parachute. I tried a force from the side to make it drift but I didn't get that to work.