rotateHelper and decomposeMatrix plug-ins

[rentallmay]

...what are they good for? Neither can i find any info about them in the online docs nor can i figure it out myself.
How and when do you use them, what is their purpose?
Can anyone enlighten me?

thanks in advance

RentaLLMay

[rentallmay]

seems nobody knows the answer. Maybe i asked in the wrong board. Maybe i should have put the question in the Maya Developers/MEL section

thanx anyway

RentaLLMay

[rentallmay]

bump bump

still groping in the dark

[scifiwasabi]

Unfortunately A|W doesn't provide documentation for those nodes.

Anyway, rotateHelper is a node that basically takes two orthogonal vectors (an up vector and a forward vector) and calculates an euler rotation...effectively similar to an orient constraint.

decomposeMatrix is a node that extracts ("decomposes") the translate, rotate, scale, and shear components of a transformation matrix.

[rentallmay]

thanks scifiwasabi

at least someone who could shed a light.
Although i still don

[campbell]

enable the plugin, and then type:
ceateNode "dependencyNode" (eg, rotateHelper)
...then you've got a node to play w like any other! open it in conexn editor to see what plugs you've got ... or list its attributes. hope this helps!

[rentallmay]

oh, now i see.
thanks very much.

But i must confess that i

[nonquad]

I was rigging something today that could have used a rotationHelper. Didn't know about rotationHelpers at the time, so I just stole angles from an aim constraint instead... no big deal. But a rotationHelper would have done the job more cleanly. Seems like a nice tool to have in a pinch.

[rentallmay]

would it be asked to much if i ask you to explain for what and in which way you would have used rotateHelper?
just to give me a little example and inspiration in what situation it can be useful.

[tim-c]

I've used rotateHelper quite a bit in conjunction with pointOnCurveInfo/pointOnSurfaceInfo. Mainly for fur projects. On Cats & Dogs I used a pointOnSurfaceInfo node to "stick" a guide hair(simple curve) to a location on the kitten's NURBS surface geometry.

At that point, the guide hair just sticks(think point constraint) and does not orient with the character. Using the rotateHelper node, you then take the "Normal" and "TangentU" of the pointOnSurfaceInfo to the rotateHelper's "Up" and "Forward". From there you plug the rotateHelpers rotation to your guide curve/hair's rotation. The result, the rotateHelper does the rotational math to keep your guide curve oriented "normal to the surface", even as the surface deforms. Much faster than expressions in calculation and interactive update.

Tim Coleman
tim@escfx.com -- MATRIX 2/3