Display accessors change the graphic appearance of a node. Ultimately, all accessor networks end up modifying the appearance of the object and, thus, use some kind of Display accessor. General Display accessors such as Rotation, Scale, or Translation change the size and position of a graphic node. One accessor, MultiRep, controls the visibility of nodes, and other accessors, such as Fill, control object-specific properties.

The different Display accessors are described as follows:

The Fill accessor operates on two polygon objects contained in a prototype: a filled polygon and a filler polygon. The value of the attribute represents a fill level. When the attribute is changed, the points of the filler polygon are modified to fill the polygon to the specified level. An angle can be specified to fill the polygon in any direction.

The following is a bottle prototype that contains two polygons: the glass and the wine. A Fill accessor is used to define the level property. The filled polygon is the glass and the filler polygon is the wine.

The MultiRep accessor (class IlvMultiRepAccessor) is used to switch between different representations of a part of your prototype, depending on an integer value. The parameters specify a list of nodes that define the different representations. When the value is changed to n, the accessor shows the n-th node in the list and hides all the other nodes.

This accessor accepts a variable number of parameters. There are as many representation states as you define rows in the parameter editing matrix. A new row is automatically created in the matrix when you validate the value of the last parameter.

The symbol prototype of the samples prototype library uses two lines, open and closed, to display a two-state switch.

The Rotation accessor (class IlvRotationAccessor) lets you set the rotation angle of an object to a given value. The value defined by this accessor is the angle (in degrees) to which the rotation must be set. The angle is stored every time it is set so resetting the value rotates the object by the angle corresponding to the delta between the old and new angles.

The Minimum Angle, Angle Range, Minimum Value, and Value Range parameters are used to compute the new rotation angle given to the input value. The new rotation is computed from the value assigned to the Rotation accessor using the following formula:

The initial value of the rotation angle is assumed to be the value of the Minimum Angle parameter so the initial position of the rotating object must correspond to this value.

The following example shows a Rotation accessor attached to the transformer prototype in the samples library.

The ScaleX accessor (class IlvZoomXAccessor) lets you set the horizontal scaling factor of an object. When the value of this accessor is changed, the object is scaled based on the new value. The scaling factor is stored every time it is set so resetting the scale to a different value scales the object by the delta of the old and new scaling factors.

This example shows a Scale accessor attached to a transformer object. The full prototype using this accessor is the transformer prototype in the samples library.

The ScaleY accessor (class IlvZoomYAccessor) lets you set the vertical scaling factor of an object. When the value of this is changed, the object is scaled based on the new value. The scale is stored every time it is set, so resetting the scaling factor to a different value changes the size of the object by the delta of the old and new scaling factors.

This example shows a Scale accessor attached to a transformer object. The full prototype using this accessor is the transformer prototype in the samples library.

The TranslateX accessor (class IlvSlideXAccessor) moves a node horizontally to a position determined by a minimum position, a position range, a minimum value, and a value range. The new position is computed from the value assigned to the TranslateX accessor using the following formula:

The use of Translate accessors is similar to the use of Scale accessors, except that Translate accessors change the position instead of the size of an object. See the transformer prototype in the samples library.

The TranslateY accessor (class IlvSlideYAccessor) moves a node vertically to a position determined by a minimum position, a position range, a minimum value, and a value range. The new position is computed from the value assigned to the TranslateY accessor using the following formula:

The use of TranslateX and TranslateY is similar to the use of scaleX and scaleY accessors.