PDA

View Full Version : IK chain twitchyness



DMarkwick
09-28-2004, 10:17 AM
What's the deal with IK chains? I got a 23 chain bone setup all set to IK, with the end bone having a goal object. For each scene that I need the tentacle to move I roughly pose it and move the goal object to get movement, but what happens is I get a twitchy odd movement like badly done stop-motion.

The tentacle is the only object in the scene.

toonafish
09-29-2004, 05:09 PM
You probably have to pre bend your bones on frame 0 to tell Layout what the preferred angle is you want the bones to bend. If the chain is completely straight Lightwave has no way of knowing what direction it should pick, so it picks both.



What's the deal with IK chains? I got a 23 chain bone setup all set to IK, with the end bone having a goal object. For each scene that I need the tentacle to move I roughly pose it and move the goal object to get movement, but what happens is I get a twitchy odd movement like badly done stop-motion.

The tentacle is the only object in the scene.

DMarkwick
09-29-2004, 05:43 PM
You probably have to pre bend your bones on frame 0 to tell Layout what the preferred angle is you want the bones to bend. If the chain is completely straight Lightwave has no way of knowing what direction it should pick, so it picks both.

Yeah I done that... I pose the chain roughly so all angles are non-zero, but still I get the twitching.

SplineGod
09-30-2004, 12:39 AM
Lightwaves native IK doesnt handle long IK chains well. You have to add multiple goals and it gets messy quick. If you have LW8 I would use IKBooster. If you dont I would use selection sets. I have a free rig on my site that uses selection sets to help animate a tentacle via FK. It works pretty well. :)

DMarkwick
09-30-2004, 04:42 AM
Lightwaves native IK doesnt handle long IK chains well. You have to add multiple goals and it gets messy quick. If you have LW8 I would use IKBooster. If you dont I would use selection sets. I have a free rig on my site that uses selection sets to help animate a tentacle via FK. It works pretty well. :)

Ah. IKBooster solved all my ails :D thanks very much. I really must fork out for the new printed manual, obviously I never found this in the v7 manual, being as it's not in v7. PDFs just don't do it for me.

IKBooster seems to be very, very nice but I can't believe that native IK is so poor. Anyhow, kudos to you :)

SplineGod
09-30-2004, 09:28 AM
LWs native IK isnt that poor actually. Its just not good for that. Also theres not any good material arouond on the proper use of IKBooster except for my video on Getting started with IKBooster available at www.kurvstudios.com. :)

DMarkwick
09-30-2004, 06:33 PM
LWs native IK isnt that poor actually. Its just not good for that. Also theres not any good material arouond on the proper use of IKBooster except for my video on Getting started with IKBooster available at www.kurvstudios.com. :)

Can you supply those vids as region 2 DVDs?

Librarian
09-30-2004, 06:56 PM
Can you supply those vids as region 2 DVDs?
Learning material should always be region code free.
Makes no sense to have a region code unless itīs published worldwide at different times. :D
I may be wrong but arenīt they quicktime videos :confused:
In my opinion quicktimes is a good choice since you can copy them on harddisc and you donīt need a dvd drive :)

SplineGod
09-30-2004, 10:47 PM
DMarkwick,
These arent "video" DVDs, theyre data DVD with the quicktime movies on them. As Librarian mentioned theres no region encoding on them so all is well :)
Viewing the LW interface on a TV is the worst way to view this stuff. The resolution of DVD is lower then the quicktime movies on the DVDs.
Thanks! :)

DMarkwick
10-01-2004, 02:45 AM
Coolness :)

I'l be sure to pick one up.

SplineGod
10-01-2004, 12:31 PM
Heres a review Aurora posted on the KURV forum if youre interested...
http://www.kurvstudios.com/forum/showthread.php?threadid=39