View Full Version : Rotoshapes Points Question

02 February 2007, 11:55 PM
Hey Everyone,

Lets say I have a roto shape keyframed throughout a sequence of 200 frames. Is there a way to delete the keyframes for a specific point (knot) only and not the whole rotoshape?

I've used the "delete keyframe" when I have a knot selected, but it deletes the keyframe for the whole shape at that particular keyframe. I tried to find info for the points on the curve editor but only find the keyframes for the Shapes Transform Control.

I just want to know if Shake lets us delete keyframes on a per point basis or does it only do it on a per shape basis. I've used roto specific applications before, like silhouette roto, which allow me to delete keyframes on the points as well as the transform node. Thank you for any help.

03 March 2007, 12:52 AM
select your roto node, go in the curve vue, click "selected", and edit your rotoshape from here it's more confortable, you can delete one point of your rotoshape directly on the shape, but it will interact on your whole shape, don't know what you really mean with your commotion example, if you delete only one knot at on a specific keyframe it will be deleted on every keyframes, no ?

03 March 2007, 01:42 AM
Thanks interference for your input. I did do that, but again I can only delete keyframes from the whole shape.

To clarify my question. I am rotoscoping a person's face for a span of 200 frames. I have a shape dedicated for the lower part of the mouth / chin area. I have set keyframes on that shape all throughout the 200 frames. Now let say starting from frame 150 till the end, there's one specific point on the rotoshape that I would like to delete it's keyframed position throughout that 150-200 framerange without affecting the position of the other points of the rotoshape. There seems to be no way to do that; I can't get information specific to that point in the curve editor. If I use the "delete keyframe" it deletes the keyframe for the whole shape at that particular frame, which is not what I want, I just want to delete the position of a point at that particular frame. Any suggestions would be helpful.

At the last place I worked, we used a roto program, which would let me select all any keyframes throughout the timeline and then highlight any point of the rotoshape and hit delete. It would delete just that point at the highlighted keyframes. Which is nice, because I can highlight all the keyframes say between frames 75-125 and select any point in the shape and hit delete. The keyframes for that point are now gone from 75-125, now I can go to the keyframe prior to 75 for that particular point and reposition it and setting new keyframes within that range.

Sorry for the long clarification. I know Shake's roto isn't the best, but if anybody has any suggestions, I would greatly appreciate it. Thanks.

03 March 2007, 11:43 PM
Sorry, your SOL. Only Combustion allows you to do that.

03 March 2007, 01:58 AM
Thanks beaker,

It became clearer to me that it couldn't be done.
Time to tweak some roto.

03 March 2007, 08:49 AM
if you're on 4.0 or later you can attach a tracker to that point and have control over the position through the tracker.

03 March 2007, 05:57 PM

That's a creative work around; I'll have to mess with that to see what results I get. If not, again, I'll just have to reKeyframe the shape, not the end of the world. Maybe Apple
shake/software developers can implement a feature such as this for new Apple compositing software that is in the works.

03 March 2007, 06:26 PM
Rather then going in and tweaking 1 point, just make another rotoshape to add or subtract from your current shape. Tweaking a single point after you have already refined it will only give you bouncy roto.

03 March 2007, 06:37 PM
but you have to match the new shape with the older one in animation so instead of animating 1 point you animate minimum 3.

03 March 2007, 06:44 PM
but if you already refined your roto down to 2's or 1's, you guaranteed to get bouncy roto if you go in and tweak that one point for every keyframe.

03 March 2007, 12:05 AM
Beaker and Adisan thank you again for your responses.

Beaker, I did have my roto refind down to 2's and in some places 1's, and what I did was went ahead and added another shape to add to the chin shape that was already there as you suggested. I had done a previous test just tweaking the one point, but as you mentioned it was jittering and really didn't make the overall roto any better.

Adisan, I tried adding another roto shape first before trying the tracking method. But thank you again for suggesting that.

03 March 2007, 06:29 AM
glad one of the methods work, solutions are always problem dependent. more solutions more chances to solve the shot.

03 March 2007, 11:34 PM
but you have to match the new shape with the older one in animation so instead of animating 1 point you animate minimum 3.Make the second shape by copying the first shape, so your curves will be in the same place to begin with. Delete the key you're trying to delete on the second shape (yes, all the knots on the frame). Make a third shape and KeyMix the first and second shapes using the third. That way your deleted key only has an effect where the KeyMix shape is. Yeah this will get heavy if you do it several times in one comp but it might give you a little more control.

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03 March 2007, 11:34 PM
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