Controlling an f-curve animation speed based on a path's Evaluation Time curve?


I have a camera following a path, and I have the camera rotation animated by f-curves the traditional way. What I want to do is whenever I make whatever changes on the path speed on the Evaluation Time curve, I want to somehow sync the rest of the camera animation with it. This way I could have the camera rotation animation take place always at the same points along a path.

Is this possible?


Ok, so I made some progress with this, but not exactly the way I wanted to.

I discovered that I can make an animation evaluation curve, similar to the path speed one, if I convert my animation to an Action (simply by switching to the NLA editor view), then selecting my animation strip, then activating the “Animated Strip Time” selection from the properties panel. Now, if you enter edit mode with ‘tab’ in the NLA and switch to the Graph editor view, an extra curve will be available for controlling Strip time. HOWEVER, there doesn’t seem to be a way to control the values with a Driver (since the values are by default, like, keyframed and you can’t remove the green and you can’t have both keyframes and drivers at the same time on a property). A workaround is simply copying-pasting the Path Evaluation curve into the object animation Strip Time curve.

I will report back if I find a better way to do this.

If I understand you correctly you have parented the camera to the path using follow path to move the camera along the path. When you do this the evaluation time has modifier automatically added and so you cannot add keys to the f-curve. If you want to control the speed by modifying the f-curve you first have to remove the modifier in the graph editor (press n to see the modifier panel if you can’t already); then you can add keys where you want by control-left clicking in the graph editor.

Another way of controlling speed along a curve would be to add a follow-path constraint to the camera and animate the offset.

No it’s not that. As I explain, I want to control other kind of animation belonging to other objects, based on my path speed evaluation curve. I also posted a follow-up reply above which explains my current work-around.