I have been thinking about this for about a week now. This actually made me take a brake from Construct but now I'm back at it again and still cant figure it out.
I have a scrolling background, which is basically set that if I move around it scrolls along with the movement. I can go faster and slower. So the player sprite is standing still only the background is moving.
Now I would like the randomly spawned items to move in relation to the background and to their position and still have their own movement. So if and sprite/item is moving let us say 10 pixels, when I scroll the background forward it moves less, and I can catch up to it, and when I move back it moves faster, as the combination of my speed is added to its speed. When I - the background is still, the item moves at its own speed only.
I am getting nowhere with this, I know I have set the bar high for myself, any nudge in the right direction would be greatly appreciated by me.
In using the custom movement behavior on the background as well as on the spawning sprites/items. I tried pinning them and then also giving them some speed but it doesn't seem that the 2 behaviors work together.