Class Name: Color Index Control Link

Superclass - Control Link

Definition

The specialized Control Link used to provide the connection between an ordered aggregation of Expressions and the target fields of a Color Index.

The color_index field is 1-based index into the ordered aggregation of Expressions, and is used to select the specific Expression that defines Color Index's index field.

The intensity_level_index field is a 1-based index into the ordered aggregation of Expressions, and is used to select the specific Expression that defines Color Index's intensity_level field.

Primary Page in DRM Diagram:

• 17

Secondary Pages in DRM Diagram:

• 14

Example

1. Consider a Geometry Model within a Model representing a tree, where the geometry consists of a single Polygon defined with Stamp Behavior.

                            <Geometry Model>
                                    <>
                                    |
                        <Union of Primitive Geometry>
                                    <>
                              -----------------
                              |               |
                              |               |
                          <Polygon>   <Stamp Behavior>
                             <>
                         -------------
                         |           |
                    <Color Index>  <Image Mapping Function>
                         <>
                         |
                <Color Index Control Link>
                         <>
                         |
                      <Variable>
   

   The Polygon's appearance is determined by a Color Index and an Image Mapping Function. However, for every Geometry Model Instance of this tree, the data provider wants to be able to vary the intensity_level of the Color Index, so that its contribution to the overall color of the tree changes from instance to instance. Consequently, the Color Index has a Color Index Control Link, which specifies a Variable that controls the intensity_level of the Color Index, so that each Geometry Model Instance can supply its own Literal to determine the percent contribution of the Color Index to the appearance of the Polygon.

FAQs

What does a Color Index Control Link control?

A Color Index Control Link controls the value of the index stored in the Color Index, the value of the intensity_level stored in the Color Index, or both.

Can I use a Color Index Control Link to change the Color Table accessed within a Color Table Group?

No. The index always refers to the primary Color Table.

Can I use a Color Index Control Link to switch from one Color Table Group to a different Color Table Group?

No. The link to the Color Table Group is an association within the given transmittal, and associations cannot be changed dynamically.

Constraints

Composed of (two-way)(inherited)

• one or more {ordered} Expressions

Component of (two-way)

• one or more Color Indices

Inherited Field Elements

Field Elements

Notes

Fields Notes

description

 A text description of what the Control_Link is for

color_index

 index of the expression defining the <Color Index's> index field;
 0 means that the <Color Index's> index field is not controlled

intensity_level_index

 index of the expression defining the <Color Index>'s intensity_level
 field; 0 means that the <Color Index's> intensity level field is
 not controlled