WorldExpression Class

List of Functions:

This class is used to create a world expression, that executes an arbitrary expression (a script). An expression can be executed for the other nodes if they are assigned as child nodes of WorldExpression. The child nodes will inherit transformations (if any) of the world expression and will be transformed relative to the pivot point of WorldExpression.

Implementing World Expression Script

A WorldExpression script can be implemented as follows:

As a simple sequence of functions' calls. For example:

Source code (UnigineScript)

// get the WorldExpression node
Node node = getNode();
// apply transformation to the WorldExpression node
node.setTransform(rotateX(cos(time * 3.0f) * 2.0f) * rotateY(sin(time * 2.0f) * 4.0f) * rotateZ(sin(time * 1.0f) * 8.0f) * translate(0.0f,0.0f,1.1f));

As a set of functions and classes. For example:

Source code (UnigineScript)

// create resources. This function is called on world load, when not all of the nodes can be loaded					
void __constructor__() { ... }
// delete the created resources
void __destructor__() { ... }

/* 
 */

// implement any required functions
void print_message() {
	log.message("Hello from WorlExpression!\n");
}
 
// implement a function that the WorldExpression will execute each frame
void my_update() {
	...
	print_message();
	...
}
	       
// execute the update function
my_update();

Notice
							Do not forget to call the function that should be executed each frame in the script.
						

Inter-Script Communication

Each WorldExpression has its own scope. You cannot directly set or get variables to or from the WorldExpression (as memory corruption occurs).

If a WorldExpression calls a function of a world script:

Source code (UnigineScript)

// World script
namespace WorldScriptScope {

	void worldScriptFunc(string arg) {
		log.message("World script code: %s\n",arg);
	}
}

Source code (UnigineScript)

// WorldExpression
engine.world.call("WorldScriptScope::worldScriptFunc","hello from WorldExpression");

If a world script calls a function of a WorldExpression:

Source code (UnigineScript)

// World script
namespace WorldScriptScope {

	void worldScriptFunc(WorldExpression expression) {
		expression.call("worldExpressionFunc","hello from the world script");
	}
}

Source code (UnigineScript)

// WorldExpression
void worldExpressionFunc(string arg) {
	log.message("WorldExpression code: %s\n",arg);
}

Script Functions

The following internal functions are available within the WorldExpression script:

Node getNode() - returns the WorldExpression node.
Node getChild(int num) - returns the WorldExpression child node by its number. If the child is not found, returns NULL.
int getNumChilds() - returns the number of WorldExpression children.
Node getParent() - returns the WorldExpression parent node. If there is no parent, returns NULL.

To get the WorldExpression node and its parent, you can write the following in the WorldExpression script:

Source code (UnigineScript)

Node node = getNode();
Node parent = node.getParent();

Now you can, for example, operate with all of the WorldExpression children as follows:

Source code (UnigineScript)

forloop(int i = 0; getNumChilds()) {
	Node child = getChild(i);
	log.message("The type of the node is: %s\n",child.getTypeName());
}
// this example shows the type of each WorldExpression child

WorldExpression Class

This class inherits from Node

Members

WorldExpression (vec3 size = 1)

Constructor. Creates an arbitrary expression to be executed.

NoticeAn expression is executed only when its bounding box is in the viewing frustum or when the camera is positioned within this bounding box, so the size is important.

Arguments

vec3 size - Size of the bounding box. This is an optional argument.

variable call (string name)

Calls a world expression function from any other script.