Radial Fast Blur for Car Light Effect - Center Won't Move

[Team Castle]

Attempting to add a radial fast blur effect to a car to simulate car lights on the road.

 I have a small Ellipse path with a white fill (20px x 10px oval) as the layer under the car layer. I added a CC Radial Fast Blur to get a car light effect.

The Ellipse is parented to the car layer, which is running along a track path.

When I press play, the car moves, and the lights move with it, but the radial fast blur center does not move. Not following the same angle of the car, and positioned in one place.

I tried to parent the CC Radial Fast Blur center (which effects the source direction of the light) to the car but no effect.

I have attempted "Auto-Orientation" but it had no effect.

Does the radial fast blur not have a moveable center?

Photos shows light position starts in desirable position then about 2 seconds into play, the center of the radial fast blur hasn't moved and looks off compared to the car and road. The white circle and the actual effect are moving with the car, but the center won't budge.

Note in the "lights bad" photo, the anchor point as shifted down but the radial fast blur center is still at the finish line.

Thank you.

[Mylenium]

Effects use realtive intra-layer coordinates. Of course applying them directly while merely transforming the layer won't do much. Likewise, applying position-sensitive effects to adjustment layers may require to use expressions to convert the coordinates. At the very least in your example you would have to link the effects' point control to the position of the dots, but since they are already parented to the car you already arrive at this conundrum that will require you to use a toComp() expression to get correct positioning.

Mylenium

[Team Castle]

So I put "to Comp()" where and what in the quotes?

I attmped to put "toComp(effect("CC Radial Fast Blur")(1))" in the Radial Fast Blur Center but that did not work.

[Rick Gerard]

Instead of fiddling with expressions that calculate the angle between the layer just pre-compose the headlight layer, move the Anchor Point of the nested headlight comp to the center of the car, and then parent the headlight pre-comp to the car. All done. 

The expression is going to get complicated very quickly because you'll have to calculate the angle, the relative position, the rotation of the car layer... Dan Ebberts could probably do it in a minute but I wouldn't even go there. 

[Team Castle]

This is a perfect solution, thank you for the simple work around.

I was able to pre-compose the lights to the car and the center moved accordingly. 

Flawless effect thanks to you!