animation is going forwards, but appears to be going backwards

[P...@adobeforums.com]

I have an animation of a car with the road moving under it. I animated texture on tires to simulate motion, but even though the animation is moving in the correct direction, the tires appear to be moving backwards. I've experimented with different speeds, but it still looks backwards. Any ideas?

[David_W...@adobeforums.com]

Kind of like helicopter blades?

[Aaron...@adobeforums.com]

Try putting some motion blur on the tires.

What you are seeing is a temporal sampling artifact. The wheels are spinning at a speed such that each frame captures them in a position that looks to the eye like it is, in fact, behind the previous position instead of in front of it. Our brains see this as backward motion. Motion blur should help by making AE pretend that it is sampling across a range of time instead of sampling just one instant.

If motion blur doesn't fit the look of your piece, then you'll have to go back to experimenting with speeds. There will be ranges of rotational speeds that will let AE catch the wheels just right and make it look like the wheels are rotating forward, though you might still not like the results, since the wheels will likely look like they are moving too slowly.

[P...@adobeforums.com]

I'll pursue the motion blur idea. Thanks!

[Aaron...@adobeforums.com]

Of course, when I had to do spinning car wheels for an animated intro, I didn't make them "spin" at all. If I recall correctly, I took the hand-drawn artwork and applied a displacement map that was basically some dancing fractal noise run through the Polar Coordinates filter. Or something like that. The idea was to make the highlights painted on the rim of the wheel shimmer in a concentric fashion, giving the impression of very fast rotation. I might have added some radial blur, too. It all depends on what sort of artwork you are starting with.