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.
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.
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.
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.
See Also#
- Article on Nodes that lists the main differences between the regular nodes and reference nodes
- Article on Node Reference
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:
#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:
// 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);
};// 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:
#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.
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.// 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.// 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.// 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
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:
// 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();