Transferring Object Positions for a Single Layer to Frame 0

[muffysb]

I'm animating an object around a complex series of obstacles over 1600 frames, and I need to have a dashed line follow the object as it moves -- the typical "boat charting a course across a map" effect.

The dashed line itself is created on frame 0 and it remains unchanged through the whole animation...as the object moves over it, I enlarge a "line mask" object which gradually reveals the line. So far so good.

My problem is this: As I develop the animation, I move the object to where I want it to be next, tweak it and apply all the secondary motion I want, then I go back to frame 0 and add another segment to the dashed line so it follows the object. But I have a heck of a time positioning the line's endpoints in frame 0 to where the object will eventually be in frame 1200.

To do this, I've created several "dummy layers" that are just large dots. At frame 1200, for example, I'll delete all the animation for a dummy layer, then position the dot where I've moved the object to. Then I need to drag the dot's keyframe all the way along the timeline back to frame 1. THEN I need to eyeball where the dot is in frame 1, flip back to frame 0 (which makes the dot move back to its origin point), add a line segment which ends where I think the dot was, flip back to frame 1 and compare the endpoint with the dot, flip back to 0 and move the endpoint slightly to where I think the dot was, and keep repeating this until I line them both up.

This seems overly complicated. If I could switch to frame 1200, move the dot layer to where my object is, then apply the dot's position back to frame 0 it would save a lot of work: I wouldn't need to delete its existing animation, drag the new keyframe, or flip back and forth between frames 0 and 1.

I can't just enter raw X and Y values for the endpoints because my object's origin is centered on the object itself (for rotation).

Can anybody suggest a better way of doing this? It will save me from a future of crippling tendonitis, or at least forestall it for a few months.

Cheers,
Muffy.

[lwaxana]

viewtopic.php?t=12947&highlight=stroke+path

This "write on" effect might help with a different approach to draw the line. I haven't tried it yet, but the video tutorial makes it look really useful for this sort of thing.

[muffysb]

Aha, sometimes just typing out a problem is enough to make you think of a better way!

I can't use the raw X,Y position for the OBJECT, but I CAN use the raw X,Y position for the DOT layer. I can move the dot to the object's position, view the dot's X & Y values, then go back to frame 0 and enter those values for the line's endpoint. Voila!

[muffysb]

Thanks, Lwaxana! That's even better!

I'd dismissed using the layer trails because of all the zooms and pans between frame 0 and frame xxxx, but after reading your link I remembered the View > Direction > Front trick and...yes! There are the trails in frame 0, showing a perfect series of trails I can simply trace!

Thanks again! This is the perfect solution.

Cheers,
Muffy.

[slowtiger]

In a case like this I use some way of trailing to produce a temporay image of the moving object, which I render and use as a guide in #0.

[muffysb]

In a case like this I use some way of trailing to produce a temporay image of the moving object, which I render and use as a guide in #0.

You use Motion Blur for a reference? Or you apply the effect in a third-party program?

[Genete]

But I have a heck of a time positioning the line's endpoints in frame 0 to where the object will eventually be in frame 1200.

Doesn't onion skin help? (You can make visible the key positions of the object by adding a onion skin mark at that 1200 frame)
-G

[muffysb]

Doesn't onion skin help? (You can make visible the key positions of the object by adding a onion skin mark at that 1200 frame)
-G

Yes, onion skin would work too (with the view changed from "Camera" to "Front")!

The good thing about viewing movement trails is that they show the slight ease in/out curves of an object that moves from point to point. The bad thing is that you need to select the object and choose the translate layer tool each time you want to view the trail, whereas onion skins remain onscreen.

Both methods are WAY better than what I was doing before! Thanks all!

[slowtiger]

And here's the stone age tool tip right from the veteran: if you use a flatscreen monitor, pin a piece of transparent paper or a cel onto it and trace the positions with a pencil ...

(Sometimes I mark certain positions on my screen with post-its. Very helpful and much faster than any software solution ...)