rotation script controller Help

The reason

($DummyB.rotation - $DummyC.rotation) * 0.5

does not work properly is because the script controller uses quat values as opposed to the euler angles. Quaternion math a bit harder to grasp and sadly not so simple.

So you said wiring them seems to work for you. Why go with the script controller then? Why do you need another controller with wiring? I'm having trouble understanding what your having an issue with.

First of all thanks a lot for answering!
This is what Ive done untill now and what I need... it will be probably easier to understand:
I have objectA and objectB (yellow dots in attached file)
both are looking at eachother (look at constraint) but have position constraints with different objects. (this is something that i do to get only the x rotation when i calculate the difference between A and B)
Both have different upnodes in the orientation constraint
I have three test objects (red points in the attached files)
and i want them to rotate 25 50 and 75 percent of that rotation difference
i also want them to rotate averaging even when the objectB rotates more than 360 degrees

the max has some animation... of course this is a simplified version of what i want to do but it has the same issue and you can see why i cant use a wire

hope it helps

what i found until now is something like this (script controller over the transform of my test points)

dependson $objectA $objectB
r1 = $objectA.transform.rotationpart
r2 = $objectB.transform.rotationpart
r = slerp (normalize r1) (normalize r2) 0.5
--(or 0.25 or 0.75)

t = $TestObjectParent.transform.translationpart
--($TestObjectParent is the object which i will use to control the position of the test objects)

s = $TestObjectParent.transform.scalepart

Is this correct? if so... how do i put the matrix back together with all this values... will this work when the rotation goes above 360 degrees?

Thanks for reading!

(r as matrix3) * (scaleMatrix s) * (transMatrix t)

this would make a new transform matrix for the rotation position and scale but it would not rotate the way you want it.

Slerp uses the shortest distance to achieve the rotation. This might help you understand it a little better of why it wouldn't work.

eulerToQuat (eulerAngles -90 0 0) --result will be (quat 0.707107 0 0 0.707107)
eulerToQuat (eulerAngles 270 0 0) --result will be (quat 0.707107 0 0 0.707107)
(eulerAngles -90 0 0) == (eulerAngles 270 0 0) --this will equal false
eulerToQuat (eulerAngles -90 0 0) == eulerToQuat (eulerAngles 270 0 0) -- this will equal true
quatToEuler (quat 0.707107 0 0 0.707107) -- will always be (eulerAngles -90 0 0)

The rotation property of a node or in other words

$.rotation

return a quat value. A 50% from (eulerAngles 0 0 0) to (eulerAngles 270 0 0) would be (eulerAngles 135 0 0). Slerp calculates Quat values and not Euler so it would treat(eulerAngles 270 0 0) as (eulerAngles -90 0 0) thus making the 50% a (eulerAngles -45 0 0).

I am starting to understand how quat values work (just a bit) but then what should I do? if i can´t wire or use orientation constraints and I want to have the same result as when i use wire on objects with the same parent.
Is there any way to extract that rotation as if the parent is the same of the test objects parent?
Again thanks for taking the time to answer

To get node’s rotation relatively to its parent u can use

$.rotInParent  --you will recive point3 value as result

can I get the rotation relatively to another object which is not the parent?

Are you try

-- let say you have two objects stored in variables "curObj" and "otherObj"
rot = in coordsys otherObj curObj.rotation

Or you can use ExposeTm helper object, align to other object and pick curObject.
You can see then all infos that you need

I didn´t know about the ExposeTm helper... super tool! I just tried using it but if y try to wire it and apply a *0.5 it will jump as expected when i pass the 180 degrees... what a shame!
When I tried using $.rotInParent i got values even when i rotated over 360 degrees...
Basically if I find a way to get values over 360 degrees in the same way (respectively to another object which is not the parent) as using ExposeTm helper I would be able to finish my rig
besides all that... I really apreciate your help, hope I can help with something some day

If you want to have rotations not flip while when it goes over 180 then your gonna have to depend on the Euler Values from the Euler rotation controller from your reference node.

Here is a copy of your current file with a float script on the x rotation controller with in the Rotation controller. If this is what your looking for or if it works as expected let me know.

Im using Max 2011 so i hope you can open it.

it is what i was looking for in terms of how the values work but I´m still taking the value from the absolute x euler of the control... since the control is not parented and free from the rest of the system y created the extra point ($objectB which you hided) but that point has an orientation constraint on it so i don´t have that track to select... that´s why in the beginning I tried to extract that value getting the difference between two point.
As you can see in this file when you move the control spline around even if you rotate it to look at the system the other bones will stop working which makes sense because the euler of the value that You´re taking is a world value and it´s not referenced to the system coordsystem.
Now Im starting to think that the difference between those two rotations will never give me a value over 360...
The system is a very complex rig of a tentacle arm with stretchy bones and controls for every joint... right now I´m using the control for the position of the IK and the extra control for the rotation. I´t can´t be impossible to keep the last bone of that rig aligned to the control and the rest averaging to that rotation
If i ask for $.rotInParent i get a value in degrees and if i rotate $ over 360 I get that value like 854 degrees. Now if I ask for the rotation like barigazy said:
"rot = in coordsys otherObj curObj.rotation"
I´m getting different values (quat i think)... any ideas?
I´m learning more in this conversations than what I´ve learned in weeks Thanks again.

Look at this topic in MXS HELP http://docs.autodesk.com/3DSMAX/15/ENU/MAXScript-Help/index.html?url=fil…
U can use for quat conversations theses functions

quatToEuler2
--example
rot = quatToEuler2 (in coordsys otherObj curObj.rotation)
--or
quatToEuler order:

Guys... thanks for your time...Im away from my PC till wednesday but if I solve the rig Ill share the files here next week... Will keep you up to date!

barigazy: with those methods i always get values under 360 degrees... am i doing something wrong or there is just no way of getting the same values as the ones you get using the method "$.rotInParent"?

I discovered that if I ask for rotinparent on any object it will give me the absolute value but if i apply an orientation constraint to it then i get valuez under 180°
Even after deleting the constraint the value was under 180° so I guess that when you apply a list controller something changes....

I saw a few tutorials and also riggs for characters which have the same problem with the forearm... --i also saw very complex Riggs using an extra control for the rotation of the hand and and one control for the position of the ik solver.
I suppose that what i was looking for is either impossible or very difficult to achieve but anyways... with the learned stuff i am developping an autorig for arms and legs.... probably not the shortest way for the code regarding my script acknowledge but it´s working and it wires a huge amount of stretchy bones automatically... will post the code here when Im done... Thanks Again for your help with this Guys!

"it is what i was looking for in terms of how the values work but I´m still taking the value from the absolute x euler of the control... "

The values in a controller will always be in parent space if that help.

" I´t can´t be impossible to keep the last bone of that rig aligned to the control and the rest averaging to that rotation"

True but you need to depend on euler angles if this is what you want to achieve (there for you need to pull information from an object using a EulerXYZ for its rotation controller). So look at and orientation constraints wont help in this matter since they calculate using quat. 90% of the rotation in 3ds max depend and work with quat. Your gonna have to get creative in some way.

The program has no way of knowing your object rotated past 180 or -180 when using quat rotation. There for you need a Euler reference in this case. Wish i could help more but your gonna have to do something similar to what I showed you in the file to achieve what you want.

when i try to use slerp on objects outside of this system it works but it jumps to other rotations when I move the master over 180 degrees

Basically I want to know if I can do with script controllers the same I do with wire parameters when I ask that one object´s rotation is another object rotation multiplied by 0.x. Making it work with angles above 180 and 360