Blending objects with eachother but not with background actionscript 3 -

i have number of objects (represented displayobjects) wish blend eachother.

however behind these objects there background not want involve in blending.

so want blend these objects eachother , afterwards use result of blending new displayobject (for example put on top of randomly colored background).

so have is:

var obj1:displayobject = getfirstobj(); var obj2:displayobject = getsecobj(); var background:displayobject = getbackground();  obj1.blendmode = blendmode.add; obj2.blendmode = blendmode.add; 

a first attempt tried putting these objects common displayobjectcontainer hoping blending mode relative objects contained same displayobjectcontainer, not seem case.

var objectspool:sprite = new sprite(); objectspool.addchild( obj1 ); objectspool.addchild( obj2 );  addchild( background ); addchild( objectspool ); 

so diddent me anywhere. appreciated.

edit: changed displayobjectcontainer sprite in last code snippet

if put objects container, , remove stage, can draw bitmapdata class , create new bitmap object representing combination. have transparent background, , it's blendmode normal, allowing use on background.

var obj1:displayobject = getfirstobj(); var obj2:displayobject = getsecobj(); var background:displayobject = getbackground();  obj1.blendmode = blendmode.add; obj2.blendmode = blendmode.add;  var objectspool:displayobjectcontainer = new displayobjectcontainer(); objectspool.addchild( obj1 ); objectspool.addchild( obj2 );  var bmd:bitmapdata = new bitmapdata(objectspool.width,objectspool.height,true,0); bmd.draw(objectspool);  var drawnobject:bitmap = new bitmap(bmd);  addchild( background ); addchild( drawnobject ); 

(untested code, luck)