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Participating Frequently
October 6, 2021
Question

Camera position moves on x axis at different speeds between keyframes although it's linear

  • October 6, 2021
  • 2 replies
  • 266 views

I've got an issue, I have 3 keyframes for the position of the camera. The camera moves across the first 2 keyframes easing in and easing out. The camera should move between the next 2 frames at a steady, continuous speed. There

The problem is that, even when I switch the keyframes to linear, the camera speeds up then slows down between the 2 keyframes on the x axis.

 

How can I get the camera to move at a constant speed between the 2 last keyframes?

 

Here's a screen recording of the problem:

 

http://www.giphy.com/gifs/rgvq73xJPUxZ5mZgEu

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2 replies

Mylenium
Legend
October 6, 2021

Well, maybe you need to fix the rotation of the globe? It seems to me you are not really accounting for the fact that this would by itself cause non-linear motion and I stupidly overlooked it as well. So rather than perfectly linear keys you likely need actual "curved" keyframes which in mathematical terms would be the inverse cosine of the rotation transform multiplied with the lens curvature, but eyeballing it should get you there as well. 😉

 

Mylenium

Participating Frequently
October 7, 2021

I appreciate your insight Mylenium! Thanks for helping with this. It seems there is no where else I can go, I've asked several people about this problem.

 

There is no rotation or movement of the object. The object is a flat map with the 3d checked.

I've just hidden the map, created a flat red square and checked 3d for that layer. I've also turned on split screen preview so you can see the camera's behavior. All movement is done with the camera. You can see how the camera wireframe is moving slow, then fast, then slow between the 2 linear interpolation keyframes. 

https://media2.giphy.com/media/zZJEkKlFhMzw0gSGSm/giphy.gif?cid=790b7611ae1d175f42c342699ffe536d5e6b8b9cedeb6550&rid=giphy.gif&ct=g

 

How is the camera moving at different speeds (slow fast slow) between two linear time and linear space keyframes?

Participating Frequently
October 7, 2021

Ah! I've discovered the problem. Easing was turned on for the camera control. Turning this off makes everything work how I would expect it works. 


Mylenium
Legend
October 6, 2021

Check the speed graph. AE treats spatial and temporal interpolation separately. You may want to read the online help on these basics.

 

Mylenium

Participating Frequently
October 6, 2021

Here's the speed graph. The speed looks constant between these last two points.