I want make a same mesh

[leonhong]

Hi all.
I'm new in Ogre3D. but I used DirectX before.

I need 100 spheres. They has a same shape. btw if I load them from resources, it wasts a memory.
so I want reuse mesh. I found a method, "createEntity(const MeshPtr& pMesh);".

so I appled that code like this.

Code: Select all

int gNumObjects = 120;//120;
int i;		

// Load Mesh from resources
Ogre::Entity* entity = m_sceneManager->createEntity( "Entity", "SphereNormal.mesh" );

for (i=0;i<gNumObjects;i++)
{

	// making node ID
	char buf[8];
	itoa( i, buf, 10 );
	string str = "Node";
	str = str + buf;

[color=#004080][b]	Ogre::Entity* entity2 = m_sceneManager->createEntity( entity->getMesh() );[/b][/color]
	Ogre::SceneNode* node = m_sceneManager->getRootSceneNode()->createChildSceneNode( str );
	node->attachObject(entity2);

	m_arrObject.push_back(node);
}

So, My Questions are these:
1. Am I right that using that code?
2. How can i check reuse mesh or not?

Thanks.

[areay]

I need 100 spheres. They has a same shape. btw if I load them from resources, it wasts a memory.
so I want reuse mesh.

Hi Leon,

Take a look at the manual http://www.ogre3d.org/docs/manual/manua ... l#Entities creating multiple entities with the same mesh does not make additional copies of the mesh.

The standard tutorial-esque code below is fine

Code: Select all

for (i=0;i<gNumObjects;i++)
{
  Ogre::Entity *myEntity = m_sceneManager->createEntity("SphereNormal.mesh");
  Ogre::SceneNode *myNode = m_sceneManager->getRootSceneNode()->createChildSceneNode("Node_" + Ogre::StringConverter::toString(i));
  myNode->attachObject(myEntity);
  m_arrObject.push_back(myNode);
}

[Kojack]

In fact you don't even need the name, it's optional for both entities and scene nodes.

Yep, entities share their mesh. You can move them, scale them and even change the material on them, but only one copy of the mesh will be in memory (so all of your spheres could have different textures, they would still be one mesh).

[leonhong]

Im appricate areay.

I was really new in Ogre.
U gave me a good code and Ill apply them right now ^^.

Btw. I have a question.
Its wierdo function, I think.

Code: Select all

[color=#008000]        /** Create an Entity (instance of a discrete mesh).
            @param
                entityName The name to be given to the entity (must be unique).
            @param
                meshName The name of the Mesh it is to be based on (e.g. 'knot.oof'). The
                mesh will be loaded if it is not already.
        */[/color]
        virtual Entity* createEntity(const String& entityName, const String& meshName, const String& groupName = ResourceGroupManager::AUTODETECT_RESOURCE_GROUP_NAME );

Why Ogre wants a unique entityName?
I think they can identify using meshName.
If u have a idea, let me know. ^^

Thanks.

[leonhong]

Thanks Kojack.

I understand. and i can use mesh more useful.

Have a nice-day everybody~

[areay]

Why Ogre wants a unique entityName?
I think they can identify using meshName.
If u have a idea, let me know. ^^

If you don't create a entity with a name then Ogre will create one for you. Using this name you can do a lookup based on the name. But as Kojack mentioned, you don't actually need to name entities or the nodes yourself if you don't want to. The example code I gave above could be simplified further to look like this

Code: Select all

for (i=0;i<gNumObjects;i++)
{
  Ogre::Entity *myEntity = m_sceneManager->createEntity("SphereNormal.mesh");
  Ogre::SceneNode *myNode = m_sceneManager->getRootSceneNode()->createChildSceneNode(); //no name now
  myNode->attachObject(myEntity);
  m_arrObject.push_back(myNode); //you might not need this either, depends if you're keeping track of the spheres after creating them
}

[leonhong]

Hi .

I thought your code is very clear!

And I alreay appled^^

thanks