Vertical parallax scrolling

I'm trying to achieve vertical parallax scrolling for my space shootemup but it's driving me crazy! I know you can change the parallax scrolling per layer but then the layers go out of sync.

This is what I'm trying to achieve (from my GM game StarForce):

, but whatever I try doesn't seem to go right!

I'm using a tall screen and constantly moving object which the view follows so I don't know if that's screwing up the parallax scrolling.

I know there is a parallax scrolling example but that's for platforms. Does anyone have a vertical parallax scrolling demo I could take a look at?

Also, if you set Parallax in editor to "yes", that layer moves way out of sync and you can only highlight objects where they used to be (with Parallax in editor set to "no")

Here's the CAPX, try highlighting the gray tiles to see what I mean.

I want the gray tiles to start near the start (bottom) of the level, like this:

<img src="http://img840.imageshack.us/img840/292/starforcescreen.jpg" border="0" />

But when I turn parallax on they are suddenly whisked away towards the end (top) of the level!

Does anyone have any ideas on this as I'm still struggling with it.

Yeah, unless I'm totally looking at this wrong it seems like something IS going a bit wonky. I just don't know what. <img src="smileys/smiley5.gif" border="0" align="middle" />

If no one can get you a good answer, I'd suggest faking parallax in the mean time. Manually scroll the sprites and have the different levels of background move faster/slower than each other to give the same look.

Hey Nicky, hows this?

db.tt/Kr9RvwD5

Working with parallax over a long stage can get tricky. The trick is to have the parallax set to "visible" in the editor, then start arranging your pieces into position while the "view" is set to 100 percent.

100 percent view is what you will see when you play the game, the origins of the objects on the parallax layer go out of sync because when you zoom out you see more of the screen and it seems to throw the position out but really doesnt.

Thanks, I think I'm getting the hang of it <img src="smileys/smiley4.gif" border="0" align="middle">

Starforce - Cursor keys to move, CTRL or left mouse button to fire.

No worries, lookin good too!

Love the sound of that gun gire.