View Full Version : motion mapping from nulls to bones?

10-31-2004, 06:12 PM

here's a heavy question!

if i export a character studio biped out of 3dsmax via fbx and load it into lightwave via the fbx importer i get a bunch of nulls where the biped used to be...

so the motion is intact from 3dsmax but they're now on a load of nulls...

so i've been trying to map/link that motion to a character with bones...

i've sort of got a result but i'd like a hand on what i really shold do as i've yet to get the walk to transfer as i'd hoped....

so what i have at the moment is i find the channel that is say used to rotate the null that was the left hip joint and note that it's the pitch channel...

i go over to my character and the hip bone and add a channel follower modifier to it and point toward the hip null pitch channel...

now then i also see there's a set driven key modifier as well...

so what's the best way to re map rotations from one null to a bone?

or should i be looking at an expression here?

...anyone done this already??

steve g

10-31-2004, 09:00 PM
What youre doing is more or less how its done. :)
Once you use channel follower you can then hit the b key in the GE to bake the motion and remove the modifier. You can use expressions or even just copy/paste the rotational channels from one to the other. You could also try using Colin Cohens free motion mapper plugin. :)

10-31-2004, 09:51 PM
CHEERS! so folower is what i should be using ..okay cool...

i've tried motion mapper but it won't work with nulls to bones...or if it does i'd like to know how you do it!...not any details on how to with th plugin........

i'm still to get a result that would actually be useful...i get loads of quirks like the start position of the bone is whacky when follower is applied...

i have been trying this plugin as well but it's not ideal for lightwave 7 or lw 8...i wish there was an uptodate version as this nearly works and i like the drag n drop approach of it...


attatch motion:

well...i need some sleep!

10-31-2004, 09:58 PM
here's my test scene....

the nulls were from a fbx import via 3dsmax/character studio

and i'm trying to map that motion onto the basic rig/character

maybe my rig is the problem...it was really rushed.

steve g

10-31-2004, 10:26 PM
You need to create a rig where each bone that corresponds to one of those nulls is at 0,0,0 for HPB. Your data doesnt have a rest pose in the fbx file. You need something like that for reference to know what rest position your character should be in. Anyways, the rotational bones should be at zero when you have them follow the rotations of the nulls. Have a pose on frame -1 as a rest for your character.