motion keyframes misbehaving

[stanatou]

I'm using PE4. I've got an image on the screen and under the motion/position properties I've got the coordinates set and keyframed at (234, 240)...so it's to the left horizontally and centered vertically. I want it to sit there for a few seconds and move back to the center of the screen. At the point where it should start moving again I have another keyframe set with the (234,240) coordinates and shortly after that another keyframe that centers the image. In the image below you can see the CTI between the 2 (234,240) keyframe markers and at that point the image has moved farther left (218.3 vs 234). It then gradually moves back to the (234,240) position. I've deleted and reset the markers, saved, closed, and re-opened the project but it made no difference. I also put another (234,240) keyframe at the CTI position which fixed the problem to the left of the new marker but not to the right. Has anyone seen this behavior before?

Stan

keyframes.jpg

[Bobby]

Stan, I am concerned that you have a lot of other keyframes for swivel, tilt, scale, etc. also going on and they may be interacting in some way. Normally I have no problem doing what you want - I do a lot of keyframing and never a similar problem.

Try cleaning off all the other keyframes and just concentrate on the x,y coordinates.

[Steve Grisetti]

If the keyframes its between represent identical positions, it could be that you may have accidentally adding some spatial interpolation between them.

To fix this, right-click on each keyframe point and ensure that any spatial interpolation is turned off.

[Bob]

Step through your position keyframes using the arrow keys next to the position values in the properties panel and check that the position values at the keyframe are what you think they should be and that you don't have any extra keyframes. It does sound like there is a keyframe to the right of the cti that doesn't have the same values as the one to the left. If the position values are not equal on either side of the cti, you will get motion. Your keyframe symbol is a diamond so you are using the default linear interpolation.

[stanatou]

I set the interpolation to 'Hold' on the first (234,240) keyframe and that seems to be working.
Thanks guys,

Stan

[Steve Grisetti]

Great news, Stan!

Sometimes if you nudge a clip a bit between keyframes, you can trigger the spatial interpolation. (Spatial interpolation lets you, for instance, create a curved or round motion path rather than a straight line.) And, even between keyframes for identical settings, that can cause some movement.