Question: I am working on a Bubble Shooter type game where I want a body not to collide with any thing else when its burst or falling down.
I cant use collision filtering because all the bodies on the scene are of same type.
I want to disable the collision. I don't want to collide a body with any other body.Some one told me to set the isSensor flag to true but again I am not able to get the flag and set it.
Please help.

Answer: 
You can also use mask bit and category bit property to change behaviour of some body and other body act as normal one.

This way you can create multiple groups of bodies which response to collision as group. Means one group has different collision behaviour than other one. 

Using this method you can perform collision filtering. That thing represented in the following example.

[Physics Collision Filtering](https://github.com/RealMayo/AndEngineExamples/blob/GLES2/src/org/andengine/examples/PhysicsCollisionFilteringExample.java)
Give negative value to filterindex of your fixture if you don't want them to collide and positive value if you want them to collide.

For removing collision

```
public static final FixtureDef PLAYERS_FIXTURE_DEF = PhysicsFactory.createFixtureDef(1, 0.5f, 0.5f, false, CATEGORYBIT_PLAYERS, MASKBITS_WALL, (short)-1);

```

and for collision

```
public static final FixtureDef PLAYERS_FIXTURE_DEF = PhysicsFactory.createFixtureDef(1, 0.5f, 0.5f, false, CATEGORYBIT_PLAYERS, MASKBITS_WALL, (short)1);

```