Modifiying Anchor Points

[Adolfo Rozenfeld]

[jkb242] “if I move the anchor point by moving the anchor point H and V sliders, the anchor point continues to remain in the center of the frame while the entire picture moves downward to allow the anchor point to be centered to the face.”

I don’t want to be too smart here, but I swear this is one of the cases where appearances are deceptive. Would you believe me if I told you that your clip is staying exactly in the same place?
Every spatial transform (scale, rotation, position) takes the anchor point as gravitional center, sort of speak. In the case of position, this means that if you offset the anchor point, it’s that point the one that will be located at the current XY position values. So PPro is doing the right thing, in a literal way. Which may not be what you expect.
In AE, you can have two different behaviors. One is the “literal” anchor point offset, which produces the results you know. The other one is using the Pan Behind tool, which visually produces something that looks like the clip stays in the same place and the anchor point moves to a new location (but in actuality, what it does is modify both position and anchor point values at the same time, so that the new position value neutralizes the anchor point offset).
Unfortunately, Premiere Pro doesn’t have a Pan Behind tool AFAIK. It would be a very useful addition.

[Jerry Black]

Thanks for you input Adolfo, I figured it out and got it to work just fine in PP CS3. The help files were of no HELP as usual, why do they even bother on such subjects?? If you are interested in the solution, let me know.

Unfortunately, everything seems doable in AE but that is not the place I usually begin. Fortunately the integration is very tight but there is still a bit of a learning curve for me with AE.

[Adolfo Rozenfeld]

Sure, I’d love to learn the solution that worked for you.

Regarding the help documents… There Adobe documentation team is conducting a survey about them right now.

https://livedocs.adobe.com/en_US/PremierePro/3.0/index.html

At the bottom of each page, you’ll see a button to “take a survey”.
It’s your opportunity to make yourself heard.

IMO, they have improved a lot recently. And also it’s worth noting that theor job is much tougher than people writing specialized books with with all the time you need after release. Many times they have to document features which are far from being finished, and then go back to fix it according to the final feature set. Not to mention simultanoeusly doing all the localizations and such things.

[Steven L. gotz]

I assume that you solved the problem by using ketframes to show the start position and scale, and then the end position and scale. Manually dragging the image in the Project Monitor helps a lot.

[Adolfo Rozenfeld]

There’s no “wrong” method and every one has a favorite way. But this approach has two well-known problems.
On one hand, you have two “competing” speed graphs instead of a collaborative relationship. You end up with something that scales faster than it moves, or viceversa.This conspires against the “silky smooth” feeling.

Second problem, because the nature of interpolation in computer graphics is to use the shorter route between two values, you may find that you’re satisfied with the start/end states, but experience unpredictable results in the middle of the animation. In a worst case, on given scale/position combos, you end up seeing the margins of the graphic.

Because of all this, the usually recommended method among animators is visually adjusting (not animating) the anchor point so that it adds “weight” to a particular zone. When you animate scale, the apparent location of the image will drift naturally towards that feature, with the same speed graph that affects scale.

While the ideal thing would be having a pan behind tool like AE has (to offset the anchor point visually while the clips seems to stay still), you can do it with just an extra step: relocate anchor point so that it is in the relative location of the clip you want, and then move the clip before animating so that its’ position is corrected. Then you can animate scale smoothly as was mentioned before.

[Jerry Black]

I used the anchor point for centering the zoom effect and that is what the procedure on which this is based:

Place CTI at the front of the image, anchor point will be fixed by default at center of image. At the point where the zoom begins set keyframe for the zoom first to get the zoom effect desired (amount of zoom). Next, while zoomed in, move the H and v postions of the anchor point so that the focus piont of the zoom (part of object to which zoom is centering) so that the anchor point is image is lined up correctly to center the zoom point. Now back out of the zoom to the first zoom keyframe and line up the first keyframe of the anchor point so that the anchor point is still centerd along the zoom axis. You can slightly move the picture inside the output window to center it in the frame when testing your setup.

Let me know if you have any difficulty with this.

[Jerry Black]

I did indeed.

[Jerry Black]

Adolfo,

I lost the note you emailed to me please resend.

[Adolfo Rozenfeld]

I don’t think I e-mailed anything 🙂
You probably received an e-mail notification of the reply I posted here.
In that case, the reply is available in this thread.