In Blender 2.9, on adding location drivers to the origin of a Curve, there is no animation even though the location values are generated by baking sound to fcurves.

Also using a Hook driver to drive the curves creates no animation. Even trying with a Cube, gives no result.

Also, there is an Error - "Invalid python expression". Since the location values are derived from sound, there is no option to link the driver "var" to this value. I tried using "self", but no result.

How to resolve this?

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2 Answers 2


Original audio fcurves were created in the Driver tab (after adding driver to the object property and baking sound).
Eventhough this creates fcurves in the driver tab, the animation just doesn't play.

Solved the issue by baking audio fcurves from the GraphEditor instead(after setting keyframes for the object property).


In the 3D window go to the menu Object - Animation - Bake action, so to bake the sound created animation into an editable curve.

  • $\begingroup$ On baking audio fcurve to action , only 2 keyframes get created (first and last) .The inbetween keyframes are missing. $\endgroup$
    – starzar
    Nov 9, 2020 at 10:22
  • $\begingroup$ Could you upload your file? $\endgroup$ Nov 9, 2020 at 11:21

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