Physics with Bullet - jMonkeyEngine 3.0 - page 439

4. The second thing is a change to ClientMessageHandler . If the message is
an instance of PhysicsObjectMessage , it should get the physicsObject
Map from the Game class as follows:
Map<Integer, Spatial> physicsObjects =
game.getPhysicsObjects();
5. A spatial should then be selected based on the objectId in the message as fol-
lows:
int objectId = physicsMessage.getObjectId();
Spatial s = physicsObjects.get(objectId);
6. The rotation and translation should be applied as physicsLocation and
physicsRotation respectively on the spatial's RigidBodyControl :
PhysicsObjectControl physicsControl =
s.getControl(PhysicsObjectControl.class);
if(physicsControl.getId() == objectId){
s.getControl(RigidBodyControl.class).setPhysicsLocation(physicsMessage.getTranslation());
s.getControl(RigidBodyControl.class).setPhysicsRotation(physicsMessage.getRotation());
}
7. Now, the pipeline for transmitting physics updates from the server to the clients
should work. If we run it, not much is happening. This is because the players in
the implementation in Chapter 7 , Networking with SpiderMonkey , weren't using
physics. They were simply coded to stick to the surface of the terrain. We can
change the player's representation to handle this.
8. In ServerPlayerControl , we add a BetterCharacterControl field
called physicsCharacter and a Boolean field called usePhysics .
9. Next, we override the setSpatial method, and perform a check to see whether
the spatial supplied has BetterCharacterControl . If it does, usePhys-
ics should be set to true and the local physicsCharacter field should be
set to spatial as follows:
if(spatial.getControl(BetterCharacterControl.class)
!= null){
usePhysics = true;
physicsCharacter =