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The SoVRMLScript node is used to program behavior in a scene. SoVRMLScript nodes typically receive events that signify a change or user action, contain a program module that performs some computation, and effect change somewhere else in the scene by sending output events.

<font color="#0000FF">NOTE:</font> This class does not exist in Open Inventor 10.0 and later.

VRML97 SPECIFICATION

This section describes the expected behavior of the node in a conforming VRML97 browser application. In some cases, the application is responsible for implementing portions of the expected behavior. Open Inventor viewer classes and IVF classes implement some of the application behaviors.

This section may reference portions of the VRML97 specification that are not present in this help file. The complete VRML97 spec is available at http://www.web3d.org.

The SoVRMLScript node is used to program behavior in a scene. SoVRMLScript nodes typically receive events that signify a change or user action, contain a program module that performs some computation, and effect change somewhere else in the scene by sending output events. Each SoVRMLScript node has associated programming language code, referenced by the url field, that is executed to carry out the SoVRMLScript node's function. That code will be referred to as "the script" in the rest of this description.

Browsers are not required to support any specific language. See the section in "Concepts - Scripting" for detailed information on scripting languages. Browsers are required to adhere to the language bindings of languages specified in annexes of the specification. See the section "Concepts - URLS and URNs" for details on the url field.

When the script is created, any language-dependent or user-defined initialization is performed. The script is able to receive and process events that are sent to it. Each event that can be received must be declared in the SoVRMLScript node using the same syntax as is used in a prototype definition:

   eventIn @I type name @i

The SoVRMLScript node should be able to generate events in response to the incoming events. Each event that can be generated must be declared in the SoVRMLScript node using the following syntax:

   eventOut type name

If the SoVRMLScript node's mustEvaluate field is false, the browser can delay sending input events to the script until its outputs are needed by the browser. If the mustEvaluate field is true, the browser should send input events to the script as soon as possible, regardless of whether the outputs are needed. The mustEvaluate field should be set to true only if the SoVRMLScript has effects that are not known to the browser (such as sending information across the network); otherwise, poor performance may result.

Once the script has access to a VRML node (via an SFNode or MFNode value either in one of the SoVRMLScript node's fields or passed in as an eventIn), the script should be able to read the contents of that node's exposed field. If the SoVRMLScript node's directOutput field is true, the script may also send events directly to any node to which it has access, and may dynamically establish or break routes. If directOutput is false (the default), then the script may only affect the rest of the world via events sent through its eventOuts.

A script is able to communicate directly with the VRML browser to get the current time, the current world URL, and so on. This is strictly defined by the API for the specific language being used.

It is expected that all other functionality (such as networking capabilities, multi-threading capabilities, and so on) will be provided by the scripting language.

The location of the SoVRMLScript node in the scene graph has no effect on its operation. For example, if a parent of an SoVRMLScript node is an SoVRMLSwitch node with whichChoice set to -1 (i.e., ignore its children), the SoVRMLScript continues to operate as specified (receives and sends events).

FILE FORMAT/DEFAULT

VRMLScript {

metadata	NULL
url	[]
directedOutput	false
mustEvaluate	false

}

EVENTS

eventIn

SoMFString	set_url
SoSFNode	set_metadata

eventOut

SoMFString	url _changed
SoSFNode	metadata_changed

Obsoletesince Open Inventor 9500 The VRML API is no longer supported. See section http://oivdoc95.vsg3d.com/content/compatibility-notes-4#Deprecation of the Reference Manual.

Reference