Converting frames with curves animation to text?

Report · Dec 04, 2024

I made a simple animation in AE with curves, which have position (and it could have other parameters such as position and scale) if i select the keyframes, and press Ctrl + C and then i press Ctrl + V on a supported text app, it copies the information such as this:

Adobe After Effects 9.0 Keyframe Data

Units Per Second 30

Source Width 4320

Source Height 4320

Source Pixel Aspect Ratio 1

Comp Pixel Aspect Ratio 1

Layer

Transform Position

Frame X pixels Y pixels Z pixels

0 865 3615 0

20 3340 525 0

End of Keyframe Data

But as you can see, there isnt any 'information' about the curve itself, or is it?

What i want is to have enough information about the curve (complex or not) in order to be able to perfectly replicate it in more softwares, such as 3D ones like Blender.

Is there any way to export this information in a way more complex way just than coordinates?

Thanks in regards.

Sebastián.

Report · Dec 04, 2024

I don't believe that what you're asking is available in After Effects.

Report · Dec 04, 2024

Here is what I get with three keyframes on a curved path:

Adobe After Effects 9.0 Keyframe Data

Units Per Second29.97

Source Width1

Source Height1

Source Pixel Aspect Ratio1

Comp Pixel Aspect Ratio1

Layer

Transform Position

FrameX pixelsY pixelsZ pixels

02002000

17649608000

365416002000

End of Keyframe Data

The first keyframe on the 2D layer is 200, 200. The keyframe data shows 02002000.

The second keyframe value is 900,800. The data shows 17649608000.

The third keyframe is 1600, 200. The data shows 365416002000.

If I change the path from a curve to straight lines between the points, the data changes to these figures:

Adobe After Effects 9.0 Keyframe Data

Units Per Second 29.97
Source Width 1
Source Height 1
Source Pixel Aspect Ratio 1
Comp Pixel Aspect Ratio 1

Layer
Transform Position
Frame X pixels Y pixels Z pixels
0 200 200 0
1764 960 800 0
3654 1600 200 0

End of Keyframe Data

Do you notice the difference? The string of numbers now has spaces just like your example because the path is a straight line. The first digit looks like it is the frame number, the second and third digits indicate position (200, 200), and the last set of digits may indicate the curve. Straight lines would be a zero.

There must be some formula for curves in the last numbers. If I change the curves using the pen tool, the new data changes the last digits. The frame number and the position properties stay the same. I don't know if anything has been published about how to interpret these number strings as curves plotted on a graph, but it's clear to me that if there are spaces between the frame numbers and position properties, the last set of numbers defines the curve.

Here's the last set of keyframe data and an animated GIF showing the curve changes that generated the different values.

Adobe After Effects 9.0 Keyframe Data

Units Per Second29.97

Source Width1

Source Height1

Source Pixel Aspect Ratio1

Comp Pixel Aspect Ratio1

Layer

Transform Position

FrameX pixelsY pixelsZ pixels

02002000

17649608000

365416002000

End of Keyframe Data

The keyframe data will be impossible to convert to a motion path in Blender or another 3D app unless you can find the formula or they use the same formula. Maybe you could export a curved shape layer that matches a motion path or even the path of an animated 3D layer in After Effects to a C4D file and extract the path that way. I did not open the graph editor and make a bunch of different speed changes to see how that affects the data.

Report · Dec 07, 2024

What you are seeing in the text for each frame is four values: the frame number followed by the XYZ coordinates. The tangent values are lost when the copied keyframe data is encoded to text. There is only information there to reconstruct a linear spline based on the original keyframe values.

It wouldn't be super hard to write a script to copy all this data to the clipboard (or to display it in a dialog to be copied). Bercause my exposure to Blender is limited to only very basic modeling, the part I don't know is how best to get this infrormation into blender. Is there a way to paste this into a dope sheet or soemething for a cubic spline, and if so, what format does it need to be in?

If you don't want to figure all that out and would like to bake the position value on each frame and copy those values over instead, an alternative would be to apply a "value" expression to the animated properties, do a "Convert Expression to Keyframes" operation, and then copy the data. Then you can copy the position for each frame as a linear spline without needing the tangents.