Position changes when size changes?

[DrewRothman]

I'm working on making a few objects "pop up" on my stage. I'm keyframing a scale change from 1x1 up to full size. I notice that when I go to the "Position and Size" on the Object panel and set the W and H to 1x1, it also changes the X and Y coordinates. When I'm dealing with smallish objects or quick scale-ups, this seems to result in a visible "jump" between the final frame of the tween and the ending keyframe. Anyone know why this happens?

[kglad · Accepted solution]

probably because of the location of the object's transform point.  you probably (but not necessarily) want this to be the object's upper left.  you can change the transform point by clicking the "free transform tool"* and moving the object's open circle**:

*

**

p.s. after learning how to control the transform point, you may find it easier to recreate your tween rather than edit your tween.

[DrewRothman]

No, the transform point isn't the issue... it's 'bottom-center'. I've made a video to show what I'm seeing.

1. I verify the transform point
2. I set an endpoint keyframe
3. I set a starting point keyframe
4. I scale the starting point to 1x1 and set the Y coordinate to the bottom of the stage.
5. I add a classic tween.

The resulting animation seems to slide to the left and then pop back to the right on the final frame.

[kglad]

i can't tell what you're doing, but it looks problematic and related to your transform point:

1. double click your object.

2. make it's reg point bottom center

3. add it to a keyframe in its own layer on the main timeline

4. check/move the transform point to bottom center

5. add another keyframe further down the main timeline layer

6. set the object's w x h to 1 x1 on the initial keyframe

7. add a classic tween

8. test

[DrewRothman]

Actually, you're right. It is the transform point. When I zoom all the way in on the first keyframe, I can tell that the transform point isn't center-bottom anymore. 

So that changes the question to "How can I lock the transform point so it doesn't move around when the object is scaled?" 🙂

[DrewRothman]

I think I've sorted it out now... the Transformation point was ok, but my Registration point was poorly chosen.

[kglad]

glad it's fixed.