Unigine::NodeReference Class

Header:	#include <UnigineNodes.h>
Inherits:	Node

A node reference is a node that refers to an external .node file on the disk, which is obtained by exporting a node from the world.

NoticeThe world can contain several instances of node references referring to the same .node file.

The .node file usually contains a pre-fabricated node (or a hierarchy of nodes) with all the materials and properties that are required for its rendering. All changes that are made for the node reference via UnigineEditor are saved into this file.

Notice

When editing the node reference via the code, implement saving changes into the .node file.

The node reference should be used instead of the node if there a lot of identical objects repeated in the world: it will enable to avoid manual editing each object if you need to make the same changes in all of these objects.

NoticeA bounding box of the reference node is equal to the bounding box of its root node stored by the reference (child nodes are disregarded).

Unlike regular nodes, reference nodes are loaded into the world faster because of the internal cache usage.

An NodeReference instance is an owner of the node (or nodes) stored by the reference, so it is responsible for loading and deleting them.

Node Reference Transformations#

NodeReference transformation differs from transformation of the node (or nodes) stored by the reference. However, matrix hierarchy is used for a NodeReference. So, when moving the NodeReference, its root node stored by the reference will also move relatively to this NodeReference. At that, the local transformation matrix of the root reference node won't be changed.

Creating a Node Reference#

To create a NodeReference, you should specify a path to the existing .node file. For example, you can export a node into a .node file and then create a NodeReference by using it:

Source code (C++)

#include <UnigineEditor.h>
#include <UnigineNodes.h>
#include <UnigineObjects.h>
#include <UnigineWorld.h>

using namespace Unigine;

int AppWorldLogic::init() {

	// create a mesh
	MeshPtr mesh = Mesh::create();
	mesh->addBoxSurface("box_0", Math::vec3(1.0f));
	// create a dynamic mesh by using the mesh
	ObjectMeshDynamicPtr dynamic = ObjectMeshDynamic::create(mesh);
	// export the dynamic mesh into a .node file
	World::saveNode("unigine_project/nodes/node_reference_0.node", dynamic->getNode());
	// create a node reference
	NodeReferencePtr nodeRef = NodeReference::create("unigine_project/nodes/node_reference_0.node");

	return 1;
}

Also you can cast a Node instance to the NodeReference. However, such type casting is possible only if the Node type is NODE_REFERENCE. For example:

Source code (C++)

// AppWorldLogic.h

#include <UnigineLogic.h>
#include <UnigineStreams.h>
#include <UnigineNode.h>
#include <UnigineNodes.h>

class AppWorldLogic : public Unigine::WorldLogic {
	
public:
	AppWorldLogic();
	virtual ~AppWorldLogic();
	
	virtual int init();
	
	virtual int update();
	virtual int postUpdate();
	virtual int updatePhysics();
	
	virtual int shutdown();
	
	virtual int save(const Unigine::StreamPtr &stream);
	virtual int restore(const Unigine::StreamPtr &stream);

private:

	void nodeCast(Unigine::NodePtr node);
};

Source code (C++)

// AppWorldLogic.cpp

#include <UnigineConsole.h>
#include <UnigineObjects.h>
#include <UnigineWorld.h>

using namespace Unigine;

void AppWorldLogic::nodeCast(NodePtr node) {
	
	// check if the node is a NodeReference
	if (node->getType() == Node::NODE_REFERENCE)
	{	
		// cast the node to the NodeReference
		NodeReferencePtr nodeRef = checked_ptr_cast<NodeReference>(node);
		// set a name for the NodeReference
		nodeRef->setName("NodeReference_casted");
	}
}

int AppWorldLogic::init() {
	
	// create a NodeReference from the file
	NodeReferencePtr nodeRef_0 = NodeReference::create("unigine_project/nodes/node_reference_0.node");

	// set a name
	nodeRef_0->setName("NodeReference_0");

	// save changes into the .world file
	Console::run("world_save");
	// get the added NodeReference as a Node
	NodePtr node = World::getNodeByName("NodeReference_0");
	// cast the obtained Node to a NodeReference
	nodeCast(node);

	return 1;
}

In the result, the NodeReference_0 node will be converted to the NodeReference_casted node.

Editing a Node Reference#

Editing a NodeReference includes:

Changing the path to the referenced .node file.
Editing the node stored by the reference.

To access the node to which the NodeReference refers, use the getReference() method as follows:

Source code (C++)

#include <UnigineConsole.h>
#include <UnigineEditor.h>
#include <UnigineNodes.h>
#include <UnigineObjects.h>
#include <UnigineWorld.h>

using namespace Unigine;

int AppWorldLogic::init() {
	
	// create a NodeReference instance
	NodeReferencePtr nodeRef = NodeReference::create("unigine_project/nodes/node_reference_0.node");

	// set a name
	nodeRef->setName("NodeReference_0");

	// get a node stored by the reference and check if it is an ObjectMeshDynamic
	if (nodeRef->getReference()->getType() == Node::OBJECT_MESH_DYNAMIC) {
		// cast the referenced node to the ObjectMeshDynamic type
		ObjectMeshDynamicPtr dynamic = checked_ptr_cast<ObjectMeshDynamic>(nodeRef->getReference());
		// set a material
		dynamic->setMaterial("mesh_base", 0);
		// save changes on the referenced node into the .node file
		World::saveNode(nodeRef->getNodeName(), dynamic);
	}

	return 1;
}

In the result, the source .node file, to which the NodeReference refers, will be updated and the NodeReference_0 node will refer to the updated node with the material assigned.

Methods:

Name	Description View: Sort by:
*create*	Constructor.
setNodeName	Sets a reference to a new *.node file.
getNodeName	Returns the path to the referenced *.node file.
getReference	Returns the node stored by the reference.
canBeReference	Returns a value indicating if the hierarchy of the given node does not contain a node reference with the given name.
detachReference	Returns the node stored by the reference and releases this node of ownership so it is no longer owned and referred to by the NodeReference.
type	Returns the type of the node.

NodeReference Class

Members

static NodeReferencePtr create ( const char * name ) #

Constructor. Creates a new object that references a node from a given file.

Arguments

const char * name - Path to a *.node file.

void setNodeName ( const char * name ) #

Sets a reference to a new *.node file.

Source code (C++)

// create an NodeReference instance
NodeReferencePtr nodeRef = NodeReference::create("unigine_project/nodes/reference_0.node");
// ...
// change a reference node
nodeRef->setNodeName("unigine_project/nodes/reference_1.node");

Arguments

const char * name - Path to a *.node file.

const char * getNodeName ( ) #

Returns the path to the referenced *.node file.

Source code (C++)

// create an NodeReference instance
NodeReferencePtr nodeRef = NodeReference::create("unigine_project/nodes/reference_0.node");
// ...
// return the path to the reference node
Log::message("The referenced node is: %s\n",nodeRef->getNodeName());

Return value

Path to the referenced *.node file.

Ptr<Node> getReference ( ) #

Returns the node stored by the reference. The method should be used when you need to change the referenced node. If getReference() has returned a NodeDummy instance, it means that several nodes of the same hierarchy level has been converted into the NodeReference.

Source code (C++)

// create a NodeReference instance
NodeReferencePtr nodeRef = NodeReference::create("unigine_project/nodes/single_nref.node");
// get a node stored by the reference
NodePtr node = nodeRef->getReference();
// if the node is a NodeDummy
if (node->>getType() == Node::NODE_DUMMY){
	// print the type name of each child node of the root node stored by the reference 
	for(int i = 0; i & node->getNumChildren(); i++) {
		Log::message("%d: %s\n",i,node->getChild(i)->getTypeName());
	}
}

Return value

Node instance.

int canBeReference ( const char * name, const Ptr<Node> & node ) #

Returns a value indicating if the hierarchy of the given node does not contain a node reference with the given name.

Arguments

const char * name - Node reference name.
const Ptr<Node> & node - Node to check.

Return value

1 if the hierarchy of the given node does not contain a node reference with the given name; otherwise, 0.

Ptr<Node> detachReference ( ) #

Returns the node stored by the reference and releases this node of ownership so it is no longer owned and referred to by the NodeReference. The node is managed by the World.

To remove the node do the following:

Source code (C++)

// create a new NodeReference instance
NodeReferencePtr nodeRef = NodeReference::create("unigine_project/nodes/node_reference_0.node");
// perform something
// ...
// get the node stored by the reference and release NodeReference ownership of the node
NodePtr node = nodeRef->detachReference();
// destroy the NodeReference pointer as the NodeReference doesn't refer to a node any more
nodeRef.destroy();

Return value

Root node of the internal hierarchy.

static int type ( ) #

Returns the type of the node.

Return value

NodeReference type identifier.

Last update: 31.07.2020

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Unigine::NodeReference Class

Node Reference Transformations#

See Also#

Creating a Node Reference#

Editing a Node Reference#

Methods:

NodeReference Class

Members

static NodeReferencePtr create ( const char * name ) #

Arguments

void setNodeName ( const char * name ) #

Arguments

const char * getNodeName ( ) #

Return value

Ptr<Node> getReference ( ) #

Return value

int canBeReference ( const char * name, const Ptr<Node> & node ) #

Arguments

Return value

Ptr<Node> detachReference ( ) #

Return value

static int type ( ) #

Return value