Artwork > Finished Works and Works in Progress

Playing with IK

<< < (2/2)

johnar:
Cheers ENSONIQ5


--- Quote ---there's a few places where objects intersect (leg bones into ribs, for example) which is probably due to the model being anatomically incorrect.
--- End quote ---

 I'm noticing something which became totally apparent to me when i was working out some joint limits for froyd.
 This is not directed at you, ENSONIQ5, you'll be aware of this anyway. It's just something i've noticed as a point of interest.
 An IK characters joint movements can do some 'unexpected things', even though each joints individual limits are set to a sensible, satisfactorily restrictive number. But so can ours. If i was a skeleton, i'd still be banging my bones into each other. Our joint restrictions don't stop us from passing our forearm through our body. Our body does that.
 And so, also, with computer generated characters, even when 'suitable' limits are set, arms, (etc), can still disappear into the body.
 I suppose thats where some type of 'collision detection' might be used in the likes of 'Maya'.?
 
 Meanwhile, i suppose the lesson here is, just because the characters rig has strict joint angle limits, once you're dealing with 2 or more bones, angles can still become unpredictable, and tweaking along the chain will always sometimes be necessary.

quote from ENSONIQ5

--- Quote --- I may need to bring Eraser Man out of retirement
--- End quote ---
Nice one.

ENSONIQ5:
Spot on johnar.  Bone rotation limits will not stop unwanted object intersections, collision detection would be required for that.  Obviously CD would be required as part of a physics engine but for IK I think it will always be necessary, at times, to tweak some of the joints as you say.  And that's cool, part of the learning curve is knowing when to use IK and when FK would be better.  For example, in another thread I mentioned that arms should be IK terminating at the wrist, and fingers should be FK but in rigging the T-Rex it became immediately apparent that an IK chain down the toes (effectively 'fingers' from a joints point of view) was a far better idea.  It made the process of ensuring the toes were in contact with the ground when they were supposed to be SO much easier!

I haven't yet played with effector locking which sounds amazing and is something lacking in Carrara.  The possibilities of this are astounding!

Navigation

[0] Message Index

[*] Previous page