Shape Tweening - I need help!

[PoisonshroomClock]

So basically I made a background, right? I had it pan across the screen. It was a static image, but I thought I might try and make it really swell and make it '3D' (for lack of a better word), to simulate the perspective changing as it moves across the screen.

Anyway, I've hit a little road bump. I found out that parts of it will have to be shape-tweened, the sidewalks. The one on the left worked out fine but for some reason the one on the right is giving me a lot of trouble.

I've assigned some motion guides (i think that's what they're called? the a, b, etc points?) and messed around with it quite a bit but for some fucking reason it always loses its shape and tweens really bad (look at it to see what I mean).
I've tried redrawing it several times so there's only ever four points of the shape, but I can't get it to turn out right.

It's really frustrating, so any help would be greatly appreciated.

http://files.myfrogbag.com/ppuoua/LL_LOX_bkgrnd_pan_test.swf

[AmberArachnidClock]

Is that where the animation ends or is there more to it? Because right now it looks like the shape at the end of the tween is a weird triangle

[AstronautClock]

just use a rectangular symbol and just skew it

[Slurpee]

it looks like whole segments of the street are disappearing in addition to the sidewalk fucking up. you're not doing more than one color/shape to a tween, right? if you are, keep them to separate tweens on separate layers, and see if that works.

[Loki Clock]

If there's a great disparity between the number of vertices from the start shape to the end shape there's bound to be problems. It's really hard to diagnose this sort of thing without an fla, or even being able to see the end of the tween. Could you post screenshots of the shape hints between the two frames? Also, the sky and leftmost and rightmost walls not moving is weird.

[CaramelAppleClock]

Loki is right with the leftmost and rightmost walls.
Also, try using a rectangle and skew it

[PoisonshroomClock]

To anyone who commented on anything but the sidewalk - I know it looks fucked up; it is a work in progress. The only thing of concern to me at the moment is the sidewalk.

Anyway fuck it - I cannot be arsed screwing around with this any longer. I managed to fix up that sidewalk, only to run in with more problems. I'd have to re-apply the motion suggestion points multiple times and more. It isn't worth the time.
It wasn't turning out as dazzling as I thought it would anyway.

Oh well.

I'll show you guys what I've so far anyway, the original, static background is in the second shot. With seeing that you guys should be able to pick up on what I was trying to accomplish by editing the original background.

http://files.myfrogbag.com/ppuoua/zombie%20LL.swf

If I made the background from the ground up with consideration that it was going to be tweened about it would have been a lot easier, but yeah.

[SpongeClock SquarePants]

dude that looks fucking sweet

[PropagandaClock]

The reason it looks stiff is because the street moves as if the camera moves sideways whilst the two walls closest to the screen to not morph with the perspective of sideways moving.

Still noone on newgrounds would see that if the scene would be as short as the loop.
It all looks great else but I've told you this already

[Loki Clock]

A more subtle perspective shift with the pan would still work well, but there's really no part of the perspective pan that can't be done just as well by motion tweening rectangular movie clips.

[BlitzballClock]

Wow, insane looking flash. Love it