Virtual World Data Types
Nodes use VRML and X3D virtual world data types to define objects and the types of data that can appear in the node fields and events.
This section explains these field data types and data class types.
Field Data Types
The Simulink® 3D Animation™ product provides an interface between the MATLAB® and Simulink environment and virtual reality scenes. With this interface, you can set and get the scene node field values. Working with these values requires that you understand the relationship between virtual world data types and the corresponding MATLAB data types. The following table illustrates the virtual world data types and how they are converted to and from MATLAB types.
For a detailed description of the VRML fields, refer to the VRML97 Standard.
You can use MATLAB commands to read and save X3D files and to associate X3D files with Simulink models. For additional information about X3D support in Simulink 3D Animation, see X3D Support.
|VRML Type||Description||Simulink 3D Animation Type|
Boolean value true or false.
32–bit, floating-point value.
32–bit, signed-integer value.
Absolute or relative time value.
Vector of two floating-point values that you usually use for 2-D coordinates. For example, texture coordinates.
Single array (1-by-2)
Vector of three floating-point values that you usually use for 3-D coordinates.
Single array (1-by-3)
Vector of three floating-point values you use for RGB color specification.
Single array (1-by-3)
Vector of four floating-point values you use for specifying rotation coordinates (x, y, z) of an axis plus rotation angle around that axis.
Single array (1-by-4)
Two-dimensional array represented by a sequence of floating-point numbers.
uint8 array (n-by-m-by-3)
String in UTF-8 encoding. Compatible with ASCII, allowing you to use Unicode® characters.
Container for a node.
Single array (n-by-1)
Single array (n-by-2)
Single array (n-by-3)
Single array (n-by-3)
Single array (n-by-4)
The Simulink 3D Animation software can work with various MATLAB data types, converting them if necessary:
The inputs for the
setfieldfunction (and its dot notation form) and VR Sink and VR Source blocks, accept all meaningful data types on input. Both convert the data types into natural virtual world types as necessary. The data types include logicals, signed and unsigned integers, singles, and doubles.
getfieldfunction and its dot notation form return their natural data types according to the table above.
To ensure backward compatibility with existing models and applications, use the
vrsetpref function to define the data type support. Their names are as
Virtual World Data Class Types
A node can contain four classes of data:
eventOut. These classes define the behavior of the nodes, how nodes are
stored in memory, and how they can interact with other nodes and external objects.
|VRML Data Class||Description|
An event that the node can receive
An event that the node can send
A private node member, holding node data
A public node member, holding node data
eventIn events correspond to a field in the node. Node
fields are not accessible from outside the node. The only way you can change them is by
having a corresponding
Some nodes have
eventIn events that do not correspond to any field
of that node, but provide additional functionality for it. For example, the Transform node has an
When this event is received, the child nodes that are passed are added to the list of
children of a given transform.
You use this class type for fields that are exposed to other objects.
This event is sent whenever the value of a corresponding node field that allows sending events changes its value.
You use this class type for fields that have this functionality.
A field can be set to a particular value in the virtual world 3D file. Generally, the
field is private to the node and its value can be changed only if its node receives a
eventIn. It is important to understand that other nodes
or the external authoring interface cannot change the field.
You use this class type for fields that are not exposed and do not have the
This powerful data class serves many purposes. You use this class type for fields that
eventOut functionality. The
alternative name of the corresponding
eventIn is always the field name
set_ prefix. The name of the
always the field name with a
exposedField class defines how the corresponding
eventOut behave. For all
exposedField classes, when an event occurs, the field value is
changed, with a corresponding change to the scene appearance, and an
eventOut is sent with the new field value. These changes allow the
chaining of events through many nodes.
exposedField class is accessible to scripts, whereas the
field class is not.