need help in understanding layers and scenes in cocos2d

I have scenario in which I need to understand where should I use scene and where should I use layer. Scenario water开发者_运维技巧 is moving and fish is floating there some objects are coming fish needs to kill them by throughing any object.fish is also animated? please help where should I use scene and layer and how?

simple

if u have dependent between layers

then add them in same(one) Scene

otherwise just use different scene

Example

water fish object are dependent between them

like

water will flow continiously in background

fish will swim in it

object also floating in it

so

water has fish

water has object

moreover

if the object collide with fish then

fish should be killed.

so fish and object are dependent.

so create three layers for water,fish,object

each layer will handle its seperate touch events

by

layer.isTouchEnabled=YES;

one thing while arrangement of adding layer is important

inside water the fish can be live . so it has to inside

so

first add fish then object then ur water

water layer should be faded and transparent

so look like ur fish and object are inside water.

now one bug is while touching the fish not affect the fish .why?

bcause water is added last . so inside of water touch began method u should really handle the fish layer.