Parent Matrix

[elcid]

Does anyone know how to hook into an objects parentMatrix, with out actually affecting the parent object? Since the inheritTransform flag will replace the parentMatrix with the identity matrix, I was hoping there would be a way to feed in a matrix of your own choosing instead.

Thanks,
-Cid

[joojaa]

youd need to create a custom transform node...

However the question seem a bit silly, since thats exactly what parentting is about. You coudl use contraints to circumvent this easily tough.

If i were you id just make a extra transform between your parent and the object you have and manipulate it instead (make it not inherit things)

But what do i know what you want to accomplish, since you didnt tell us what you were up to. And i must conffess i did once make a transform node that accepted its own matrix input instead of normal attributes, for a simpler mel coding experience.

[elcid]

I would like to create a node whose final transform would have an additional cached/animated matrix multiplied against it. Think constraint node, with an animated offset, but one that still leaves the translate/rotate attributes available to the user. I've done this already in the scripting language (using that additional transform in the hierarchy method), now I was looking for a more elegant way thru the API .

[joojaa]

And that would be possible wihout writing a nodw! Infact its kindof standard parctice to use empty parents tarnsforms for this kind of stuff.

Constrain a EMPTY transform, see you can animate the offset, ists not by defaulta keyable channel but select teh constarint and make it keyable with channel controll.

Then group your object under the empty constarimned transform! and you can now key the transformas while the contrain is still multiplied in (parenting woudl be exactly what you want).

OR

use 2 constraints if you wnat weighted mutiplys.

Any particular reason why you wish to bang your head to the wall?

But seems to me that your problem might be even more trivial as the same caneasily be accompleished in many other ways too.

Care to describe EXACTLY your problem... so that i dont advice something immersly stupid to you. (se doing how you think it shoudl work and how it works are two different things)

[joojaa]

And that would be possible wihout writing a node! Infact its kindof standard parctice to use empty parents tarnsforms for this kind of stuff.

Constrain a EMPTY transform, see you can animate the offset, ists not by defaulta keyable channel but select teh constarint and make it keyable with channel controll.

Then group your object under the empty constarimned transform! and you can now key the transformas while the contrain is still multiplied in.

Any particular reason why you wish to bang your head to the wall?

But seems to me that your problem might be even more trivial as the same caneasily be accompleished in many other ways too.

Care to describe EXACTLY your problem... so that i dont advice something immersly stupid to you. (se doing how you think it shoudl work and how it works are two different things)

[elcid]

I want to make the end effector for an appendage (more accurately , the locator it's constrained to) have the ability to go back and forth between inheriting world space or its parents space (maintaining its current offset), by simply switching an attribute. With the other method the empty transform has to move, and since it's the parent of the node, its object space doesn't remain constant (relative to the character). I did something like you suggested with Mel for 'Spy Kids 3' a year or so ago. It allowed you to pick any object whose space you wanted to be in at any time (helpful when characters are jumping from spining platform to spining platform) but it wasn't as easy to edit as I would have liked (with all of the counter animating 'under-the-hood' transform keys). I'd like to see if it can be done better/cleaner and easier to edit, thru the API.