ios - infinite scrolling background - how to make objects move with ground -

i have infinitely scrolling background , character 'walking' on ground plane.

i want drop objects above , have them land on ground - far good. objects don't move ground.

can't find examples taken care of.

my 'ground' edge @ correct height regard graphics background.

    let edge = sknode()     edge.physicsbody = skphysicsbody(edgefrompoint: cgpointzero, topoint: cgpointmake(self.frame.width + 1, 0))     edge.position = cgpointmake(0, bottomshelf_itemstartposition.y)     self.addchild(edge)  

i've tried giving ground sksritenode physical properties, didn't make difference.

what best approach this? must simple way make moving ground effect objects.

adding scroll routine:

    func backgroudscrollupdate1(){      back.position = cgpoint(x: back.position.x - scrollperframeamount, y: back.position.y)     back2.position = cgpoint(x: back2.position.x - scrollperframeamount, y: back2.position.y)      if (back.position.x < -(back.size.width / 2)) {         back.position = cgpointmake(back2.position.x + back.size.width, back.position.y)     }      if (back2.position.x < -(back.size.width / 2)) {         back2.position = cgpointmake(back.position.x + back2.size.width, back2.position.y)     } 

}

update - progress

i have set physics world, ground infinitely scrolling. i've got items fall out of 'sky' , land on ground. can move things around applying impulse directly or 1 thing hitting another.

but, expected scrolling ground 'pull' things along if on ground?

i have played around different friction levels of both ground @ items touching ground, doesn't seem matter.

one thing did sort of work if set phsyics body of item circle, ground influence item, turning around in opposite direction of scrolling - when hits edge stops, rather spinning @ edge.

if part working, why wouldn't rectangle dragged along ground ?

would love see example code of phsyics world have ground effecting other nodes..