Real-Time Physics Simulation Forum

Re: [SOLVED] Position Based Elastic Rods implementation

2016-07-18T11:26:49+00:00

Mobeen, are you interested in doing the same?

Hi korzen303,
No I am a bit busy these days I have replied on your main thread.

Statistics: Posted by mobeen — Mon Jul 18, 2016 11:26 am

Re: [SOLVED] Position Based Elastic Rods implementation

2016-07-17T14:56:59+00:00

I am experiencing some problems when implementing the model mentioned above.
Here is a dedicated thread:
http://bulletphysics.org/Bullet/phpBB3/ ... =4&t=11242

Statistics: Posted by korzen303 — Sun Jul 17, 2016 2:56 pm

Re: [SOLVED] Position Based Elastic Rods implementation

2016-07-17T07:37:30+00:00

Hi Guys,

there is a new paper on this entitled "Position and Orientation Based Cosserat Rods". It is very similar to PBER but x10 faster.

http://www.cg.informatik.uni-mainz.de/p ... erat-rods/

Will give it a go and try to implement it this week.

Mobeen, are you interested in doing the same?

Statistics: Posted by korzen303 — Sun Jul 17, 2016 7:37 am

Re: [SOLVED] Position Based Elastic Rods implementation

2016-02-04T15:46:08+00:00

Glad I was of some minor help!

I look forward to checking out the implementation (someday, at least - it's not pertinent to my current project but I'd like to fiddle around with it in the near future).

Statistics: Posted by bone — Thu Feb 04, 2016 3:46 pm

Re: [SOLVED] Position Based Elastic Rods implementation

2016-02-02T15:03:25+00:00

Hi Bone,
Thanks for your reply. No i did not follow the interleaving order for solving the constraints. let me try that and revert. Thanks for the pointers.

EDIT: Thanks bone that was the problem I added the interleaving order and the elastic rod is very stable no more wiggles

Now I will be on triangle attachments and then rigid body attachments to finish this up.
After all these are done, I will be adding this to my github repository soon for others to try.

Statistics: Posted by mobeen — Tue Feb 02, 2016 3:03 pm

Re: [SOLVED] Position Based Elastic Rods implementation

2016-02-01T16:05:22+00:00

I had tried out Korzen's original demo and also experienced that wiggle exactly once. I couldn't figure out how to reproduce it so I never mentioned it. IIRC, the paper detailed a specific order of solving the constraints ... did you follow that?

Statistics: Posted by bone — Mon Feb 01, 2016 4:05 pm

Re: [SOLVED] Position Based Elastic Rods implementation

2016-01-31T15:02:36+00:00

I am now onto frame attachment constraint for orienting the tip of rod. I provide the frame attachment's initial frame such that the local z axis is pointing in the direction of world X axis. This way I would expect the rod's tip to be oriented in the direction of the world x axis. I get the desired result as shown below.

This works fine but as soon as I move the tip around such that it orients in the opposite direction of initial frame, the rod starts to wiggle around unstably and does not converge. The behavior is like someone has added life to the rod and it wiggles like a snake hard to show in a snapshot but I will try below

Anyone got any clues on what might be causing this. Is there a corner case I need to care about? Note that I store the initial frame which is always oriented such that the local X of initial frame is oriented to the world X axis.

Statistics: Posted by mobeen — Sun Jan 31, 2016 3:02 pm

Re: [SOLVED] Position Based Elastic Rods implementation

2016-01-30T08:03:07+00:00

Hi Korzen,
I have finally got my own implementation of position based elastic rods. Attached is the snapshot from my demo.

Statistics: Posted by mobeen — Sat Jan 30, 2016 8:03 am

Re: [SOLVED] Position Based Elastic Rods implementation

2016-01-14T16:41:11+00:00

Thanks Mobeen, will merge it together with the OpenMP fix

Statistics: Posted by korzen303 — Thu Jan 14, 2016 4:41 pm

Re: [SOLVED] Position Based Elastic Rods implementation

2016-01-13T08:24:08+00:00

Korzen, I have forked your repo here https://github.com/mmmovania/PositionBa ... ElasticRod
I have just removed all possible division by zeros from your fork.

Statistics: Posted by mobeen — Wed Jan 13, 2016 8:24 am