[solved] Ogre::Entity to OgreNewt::Body and vice versa?

In my code, I'm keeping a pointer to my Player entity in a variable called mPlayerEntity. Using mPlayerEntity I can get to lots of information about the player. Is there any way I can find the associated OgreNewt::Body using function calls based on mPlayerEntity? Or do I need to save the OgreNewt::Body as a variable as well?

As an alternative, if I saved the OgreNewt::Body, could I find the associated entity pointer?

Hopefully I don't have to save both values.

If you have a OgreNewt::Body , you can always get Ogre::Node from it by simple:

Ogre::Node * node = Body->getOgreNode();

but how to get an Entity from this I don't know...

[EDIT]

try this:


Ogre::SceneNode *node = (Ogre::SceneNode*) Body->getOgreNode();
Ogre::Entity * ent = (Ogre::Entity*)node->getAttachedObject(0);
//for test
Ogre::LogManager::getSingleton().logMessage(ent->getName());


now if your name in the log is the same as the name you give to the Player Entity it's working

Ps. In my test it is working

If you have a OgreNewt::Body , you can always get Ogre::Node from it by simple:

Ogre::Node * node = Body->getOgreNode();

but how to get an Entity from this I don't know...

Once you have the SceneNode like this:


Ogre::SceneNode* node = body->getOgreNode();


You can get the Ogre::Entity like this:


Ogre::SceneManager* sceneMgr = node->getCreator();
Ogre::Entity* ent = sceneMgr->getEntity("my ogre entity");


If you have a OgreNewt::Body , you can always get Ogre::Node from it by simple:

Ogre::Node * node = Body->getOgreNode();

but how to get an Entity from this I don't know...

[EDIT]

try this:


Ogre::SceneNode *node = (Ogre::SceneNode*) Body->getOgreNode();
Ogre::Entity * ent = (Ogre::Entity*)node->getAttachedObject(0);
//for test
Ogre::LogManager::getSingleton().logMessage(ent->getName());


now if your name in the log is the same as the name you give to the Player Entity it's working

Ps. In my test it is working
Drakon: yes, I was thinking of something like that myself, but I'm concerned that getAttachedObject(0) may not always return the correct attached object, and it would create a dependency when setting up the node.

What I'm thinking now is possibly to use entity->setUserAny() to pass in a pointer to my body, then use entity->getUserAny() to retrieve it. I've not worked with these functions before though.

You can get the Ogre::Entity like this:


Ogre::SceneManager* sceneMgr = node->getCreator();
Ogre::Entity* ent = sceneMgr->getEntity("my ogre entity");

Acid_Gambit: yes, I can get the entity from the scene manager if I know the entity's name. But how can I get the name if I only know the body pointer?

My objective is to keep one or the other, not both. If I'm going to keep the string for the entity name, I may as well keep the pointer to the entity itself.

well you gave the entity a name when you created it correct?


// create entity
Entity* ent = mSceneMgr->createEntity("MyNameIsAwesome", "my_sweet.mesh");

// then create node and attach
SceneNode* node = mSceneMgr->getRootSceneNode()->createChildSceneNode("AwesomeNode");

// create a temp 'get' entity to store the original entity's data
Entity* getEnt = mSceneMgr->getEntity("MyNameIsAwesome");

// then what happens?
getEnt->doWhateverIWantCuzImAProgrammerAndICan();


[EDIT] You could store the getEnt in a class and have it there for whenever your fingertips need it... but I've not tested the above code anyway, but in theory it might work.

IMO... but i'm a n00b so w/e

I think I'm chasing a dead end here.

What I was hoping for is a general purpose way to get from the entity to the body, or from the body to the entity, i.e. - something like this:

Ogre::Entity* OgreNewt::Body::getEntity(void)

Unfortunately, I think that the reason why such a function doesn't exist is that each Ogre::Node can actually be attached to any number of Ogre::Entity's.

So that's why a Body can only tell me its attached Node.

Thanks everyone for your ideas though.

Okay, I've got it working after all!

Right after I posted my last message I realized that while each Node may have multiple Entity's, each Entity can only be attached to a single Node. Therefore, all I need is mPlayerEntity, and I can do as follows...

When creating and initializing the Body, seed the Entity with a pointer to the Body:

ent->setUserAny(Any(body));

When I need to use the Body, get the pointer from the Entity like so:

body = Ogre::any_cast<OgreNewt::Body*>(mPlayerEntity->getUserAny());

Voila!

One more update on this topic...

OgreNewt::Body::setUserData() can be used to get from a body directly back to another object, such as an Ogre::Entity, or a user-defined game object, such as a class which contains both an Entity and a related Body.

For example, in my ArcObject game object class, as soon as I am finished creating my Body, I do this:
// set a pointer so we can get back to this ArcObject:
mBody->setUserData(this);

Then when I want to get back to my game object in my custom force callback, I can use this:
// get the associated game object:
ArcObject* obj = (ArcObject*) body->getUserData();

I hope this can help someone else who is just starting out.