- In the previous movie,
we moved the pivot point of an object
so that the transforms will be calculated relative
to some position of our choice.
Now we'll see how to rotate the pivot point
so that we can choose how it's aligned.
And that's important for animation.
We can see that in the front view port
if I select this shoulder right object,
and go to the rotate tool in local coordinate space.
I see the orientation of the pivot point indicated
by the rotate gizmo, as long as we are in local space
the gizmo shows us the orientation of the pivot
and it is not aligned with the object.
We can go back to the perspective view,
right click in that view port and rotate around the X-axis
and we'll see that we're not actually rotating relative
to the object itself,
but rather rotating around the world's X-axis.
Okay, I'll undo that with control Z.
There's an easy fix for this,
we can just rotate the pivot point.
Back in the hierarchy panel,
we'll enable affect pivot only
and to make it a little bit easier on myself
I can enable angle snaps up here on the main toolbar.
Turn that on and that will constrain angular rotations
to five degree increments.
And again, I'm rotating in local space.
So right click in that front view port
so we don't lose our selection and rotate just 10 degrees
around the local Y-axis, click and drag the rotate Gizmo.
And you can look down at the bottom of your screen
and you'll see some numbers in the transform typing area.
And you want to just rotate 10 degrees in Y.
Release the mouse.
And now that pivot point is perfectly aligned
with the geometry and we can test it.
Disable affect pivot only and rotate in local space.
Once again, we'll go back to our perspective view.
Right click in there and rotate around the X-axis.
And now we see that we are rotating relative
to the orientation of the object,
rather than the world X-axis.
Okay, I'll undo that with control Z.
I need to repeat that process
for every object in my hierarchy
including this other shoulder over here, shoulder left.
But I want to do something just a little bit clever here.
It would be convenient for my animation to
simultaneously rotate the two arms together.
Because they're on opposite sides of the body,
I would actually need to rotate the two arms
in opposite directions.
To accomplish that, I'm going to orient this object's
pivot point differently than the other one.
Once again, with the rotate tool active,
and local coordinate mode, and with angle snaps enabled,
I'll turn affect pivot only back on again.
And I want to rotate 100 degrees around the local X-axis.
I'll orbit around in the perspective view
and we've got the X-axis here.
And again, we're going to watch the numbers
in our transform type in area in the X-axis
and just rotate that 180 degrees.
And we see 180 down there, release the mouse.
We also want to rotate 10 degrees around the Y-axis.
We can do that in the front view port.
Right click in there and rotate that 10 degrees.
Again, we can watch the numbers at the bottom of the screen.
And when that's aligned with this left shoulder object
we can exit out of affect pivot only.
Now we can test it.
Let's select both of the shoulder objects
hold down control and select the shoulder right object.
And very importantly
we need to change our transform coordinate center
because when we make a multiple object selection,
by default the transform center
is going to be the selection center.
But in this case, we want it to be the pivot point.
And that is the first button on this flyout.
So click and hold that button and choose the first button
which is use pivot point center.
And then the rotate gizmo actually snaps
to the pivot point of the last selected object.
And then we can rotate around the local access here.
And if we rotate around Y,
we see that the two arms are moving in opposite directions.
I'll undo that, control Z.
In the perspective view, if we rotate around X,
right click in that view and rotate around the red X axis
we see that those two arms are rotating
in the same direction and that's all because
of the way we oriented the pivot points on the two objects.
Okay. I'll undo that with control Z.
That is the process of rotating pivot points
in preparation for building a hierarchy.
It's always a best practice to move and rotate the pivots
for all of the objects in the hierarchy
before creating any parent-child links.