Cineversity

I’m trying to rotate one object, based on a particular position of another object. If you open the attached project file, it makes a lot more sense. It’s just too difficult to explain with text haha.

Hi Matt,

Would this work for you?

Scene file:
https://www.amazon.com/clouddrive/share/wGVd9OfD6BTyHdnKI8rArD3fL257NT4YlR9Vg9mHBhG

I guess that the problem you had to set this up, was based on the Local R.P setting, which adds (!) only to the rotation that the Bar got from the Lever.
You need to have the Global R.P in order to have this rotation exclusively working on its own (well, Xpresso)

Let me know if there is anything else. I’m happy to look into it.

Cheers

Hey this is perfect Dr. Sassi! Looks like using the Spline feature in the Range Mapper was key. Is there a good tutorial on the range mapper that you can recommend? It seems like I can never fully understand it haha.

Hi Matt,

The spline is more like a curve in Photoshop. Values in from the bottom and values out to the right.

The spline itself is more the “fine” adjustment here. It helps to compensate for the movement, which is practically based on to axis located at pin1 and pin2. Which creates a slightly more complex movement.

The key here was to set the Global value, in your set up it was just the rotation, and with that the Local Rotation, this (!) is super important to understand, if you like to go deeper into such mechanic set ups.
The Lever rotates, and moves the bar with it, in a rotational way, then the same value is applied to the bar again, but limited to a certain range this time. So we see something that looks like un-predictable.
To over come this, the Global value for the bar ignores the parent influence and sets the bar rotation based on world coordinates.

Tutorials, well, since nothing has really changed, this would work:
https://www.cineversity.com/vidplaytut/xp_101_06_the_range-mapper
It is done with R9, an indicator that my English in it might be rusty. Sorry about that.

Let me know if that makes sense.

ENJOY.

Okay I think I can understand this. Since I was using a local rotation value, its parent was influencing the value. By using a global rotational value, it uses world coordinates only.

I must do more tutorials and read up on rotation vs global rotation as well as the range mapper :D

You got it, Matt, that is one of the most important keys in mechanical animation: The hierarchy and what the child objects will receive (or not).

With the rotation set in a Global way, the rotation value is absolute, but the position and scale can be inherited from the parent and changed on top of that with locals, or set global as well.

Since you like to dive a little bit deeper: To make this a tiny little bit more complicated, but complete – there are three options, Global, Local and Frozen. But that is all there is for PSR.

https://help.maxon.net/us/#OPOLYGON-ID_BASEOBJECT_GROUP1
Scroll down.

My best wishes