[ODE] Implementing springs for ALife

[robert.leclerc at yale.edu]

REPOST: Forgot to put a subject line

My research is in ALife and I have used ODE and Vortex so I have * 
some * 
familiarity with physics engines. Although it has been about a year 
and a 
half since I used the API's so I will have to refamiliarize myself 
with 
ODE. Currently I am looking to move away from "hinge" driven creatures 
to 
"spring" driven creatures. An example of this is with the creatures of 
Sodayplay: http://www.sodaplay.com/. As well as Fluidiom: 
http://today.java.net/pub/a/today/2004/07/20/fluidiom.html

I am hoping someone might be able to give me some advice on this 
before I 
begin to tackle this problem. i.e. what do I need to know about 
implementing a "muscle" type system? how much custom work will need to 
go 
into this? Is it problematic that there are "cycles" in the overall 
morphology?

It seems to me that slider joints may be a decent start for a muscle. 
Essentially this will be somewhat like a spring-mass system used in 
cloth 
simulation but moving to 3-dimensions and adding in means to affect 
spring 
tension. I cant really remember, but I believe there are some 
parameters I 
can set so the attached bodies are not so firmly welded to the joint 
(?). 
ODE doesn't seem to have "multi-point tension spring" which seem to be 
what is used in Sodayplay 
(http://www.sodaplaycentral.com/articles/tension1.php). 


I would be *very* interested in hearing *anything* anyone would have 
to 
offer on this. 


Thanks, 

RDL



========================
Rob Leclerc
Yale University
email: leclerc at cpsc.ucalgary.ca
email: robert.leclerc at yale.edu
webpage: www.cpsc.ucalgary.ca/~leclerc
========================