Axis parameter from a bone's direction

[beeemtee]

Hi everyone,

is there a straightforward way to convert a bone's rotations to an axis vector?

thanks in advance

Mate

[anim]

in which context? (python?,hscript?, VOPs?, CHOPs?)

but the idea is the same, just multiply desired axis with bone's global rotation matrix or inverted transposed global transform matrix

for python it would be something like

bone = hou.node("/obj/chain_bone1")
axis = hou.Vector3( (0,0,-1) )
boneDir = axis*bone.worldTransform().inverted().transposed()

above example can be easily done in hscript or VOP/VEX too

or just parent null to the bone, move tz to -1, then difference of null's and bone's global position is your direction vector

[beeemtee]

Thanks Tomas,

sorry for not beeing clear about the context. By the way, my intent was to do it with expressions,

but python seems to be much better suited for this.

The parenting idea is also very nice. Thanks for that too.

Mate

Edited March 14, 2011 by beeemtee