# Blending transition in cocos2d

In my cocos2d-iphone game, I have 2 backgrounds (CCnodes), each containing a quite complex hierarchy of sprites.

I would like to make a smooth transition between them:

• Initially, only the first background is visible
• At the end, only the second one is visible

Is there a good way to set the opacity of a full hierarchy of sprites ?

I tried to recursively set the opacity of all the contained sprites. It kinda works except that:

• I guess it's not very efficient
• I would like the opacity of overlapping sprites to be 'merged' (as if the background was one single big sprite)
• You can render one node to a texture and render a sprite containing that texture some transparency on top of the other node – rraallvv Jan 8 '13 at 4:40
• But what if I have animations running on the children (translations, scaling,...) – sdabet Jan 8 '13 at 7:26
• wouldn't be any problem, all children would be rendered to the texture as normal. please see this related question stackoverflow.com/q/14073785/1436359 – rraallvv Jan 9 '13 at 0:20

I finally solved it using a CCRenderTexture.