Issue transition.to for a display group

Solar2D General Questions/Discussion
#1

So I want to run a transition effect for a display group.

For example:

I have 3 rectangle and they all move to the same point.

Here is where it starts:

Here is where they all SHOULD transition to

But here is where they all transitioned to:

Here is my code:

local rectangle\_group = display.newGroup() local rect1 = display.newRect(50,100,50,50) rect1:setFillColor(0,1,0) local rect2 = display.newRect(rectangle\_group,50,200,50,50) rect2:setFillColor(1,1,0) local rect3 = display.newRect(rectangle\_group,50,300,50,50) rect3:setFillColor(0,1,1) transition.to(rect1,{time=1000,x=250,y=100}) transition.to(rectangle\_group,{time=1000,x=250,y=100})

It works when I change the transition code to transition each object individually:

transition.to(rect1,{time=1000,x=250,y=100}) transition.to(rect2,{time=1000,x=250,y=100}) transition.to(rect3,{time=1000,x=250,y=100})

But for the project I am working on, this is obviously not going to work.

Anybody know how to fix this?

#2

when objects are inserted into a displaygroup, they retain their relative position to eachother.

so when you move the group, you do just that, you move the group as a single object.

the solution is to do a transition.to for each object separately

hope that helps

#3

Aw that sucks.

For one of my projects I have to trainsition a display group with multiple objects inserted into it.

I am trying to avoid calling out each object individually but I guess I have to.

#4

You can still transition the group as a whole but then their relative positioning will remain. Frankly there is no logic in trying to move children individually by moving the parent.

If you transition them separately or as a group wont make a difference performance wise, to my knowledge.

#5

Also remember the display group has its own coordinates with a logic centerpoint in a square area that inckudes all children. It is that point you moved to you destination, and that is why it looks the way it did.

#6

Omg wait a second. The reason your code didnt work is you are doing 2 transitions at the bottom. Remove the one for rect1 and it should work

#7

Oh lol your right!
Thanks!

#8

You need to insert gp into sceneGroup, not x.

When you insert an object into a group, it is removed from whatever group it was in before - an object cannot belong to more than one group.

x belongs to gp, gp belongs to sceneGroup. Therefore, indirectly, x is also in sceneGroup and would be cleared up by Composer when you purge the scene.

#9

No, that’s not what I said. You can create as many groups as you like, as long as each group’s ultimate parent (or itself if it has no parent) is added to sceneGroup.

[lua]

local grandParentA = display.newGroup()

local grandParentB = display.newGroup()

local parentA = display.newGroup()

local parentB = display.newGroup()

local childA = display.newGroup()

local orphanChild = display.newGroup()

grandParentA:insert(parentA)

grandParentB:insert(parentB)

parentA:insert(childA)

sceneGroup:insert(grandParentA)

sceneGroup:insert(grandParentB)

sceneGroup:insert(orphanChild)

[/lua]

Here, everything is inserted into sceneGroup. Child belongs to parent which belongs to grandParent which belongs to sceneGroup. orphanChild has no parent or grandParent so is inserted directly to sceneGroup.

#10

Thanks nick_sherman…Now i understand…And output came correctly…

#11

when objects are inserted into a displaygroup, they retain their relative position to eachother.

so when you move the group, you do just that, you move the group as a single object.

the solution is to do a transition.to for each object separately

hope that helps

#12

Aw that sucks.

For one of my projects I have to trainsition a display group with multiple objects inserted into it.

I am trying to avoid calling out each object individually but I guess I have to.

#13

You can still transition the group as a whole but then their relative positioning will remain. Frankly there is no logic in trying to move children individually by moving the parent.

If you transition them separately or as a group wont make a difference performance wise, to my knowledge.

#14

Also remember the display group has its own coordinates with a logic centerpoint in a square area that inckudes all children. It is that point you moved to you destination, and that is why it looks the way it did.

#15

Omg wait a second. The reason your code didnt work is you are doing 2 transitions at the bottom. Remove the one for rect1 and it should work

#16

Oh lol your right!
Thanks!

#17

You need to insert gp into sceneGroup, not x.

When you insert an object into a group, it is removed from whatever group it was in before - an object cannot belong to more than one group.

x belongs to gp, gp belongs to sceneGroup. Therefore, indirectly, x is also in sceneGroup and would be cleared up by Composer when you purge the scene.

#18

No, that’s not what I said. You can create as many groups as you like, as long as each group’s ultimate parent (or itself if it has no parent) is added to sceneGroup.

[lua]

local grandParentA = display.newGroup()

local grandParentB = display.newGroup()

local parentA = display.newGroup()

local parentB = display.newGroup()

local childA = display.newGroup()

local orphanChild = display.newGroup()

grandParentA:insert(parentA)

grandParentB:insert(parentB)

parentA:insert(childA)

sceneGroup:insert(grandParentA)

sceneGroup:insert(grandParentB)

sceneGroup:insert(orphanChild)

[/lua]

Here, everything is inserted into sceneGroup. Child belongs to parent which belongs to grandParent which belongs to sceneGroup. orphanChild has no parent or grandParent so is inserted directly to sceneGroup.

#19

Thanks nick_sherman…Now i understand…And output came correctly…