Class Name: Translucency

Superclass - <SEDRIS Abstract Base>

Subclasses

Definition

An instance of this DRM class specifies the proportion of light that can pass through the given <Colour> instance, where translucency_value = 0.0 indicates that no light passes through (i.e., is fully opaque), and translucency_value = 1.0 indicates a fully transparent object.

NOTE  An object's opacity is equal to 1.0 - translucency_value. Opacity is termed the alpha of the object. Alpha values can be specified for images as part of a <Image> instance.

Primary Page in DRM Diagram:

• 14

Secondary Pages in DRM Diagram:

Example

1. The alpha value for an ambient, OTW colour can be represented in a transmittal as a <Inline Colour> instance with an <Ambient Colour> component and a <Translucency> component whose translucency_value field is set to 1.0 - alpha.

FAQs

If a DRM object has a <Colour> instance with a <Translucency> component, together with an <Image Mapping Function> component specifying an <Image> instance that also has an alpha, how are the two alpha values resolved?

That depends on the <Image Mapping Function> instance's image_mapping_method. See SE_Image_Mapping_Method for a detailed description of how <Image> instance and <Colour> instance alpha values are resolved for various mapping methods.

Constraints

• <<Publishable Object>>

Composed of (two-way)

• zero or one <Translucency Control Link> instance

Component of (two-way)

• one or more <Colour> instances

Inherited Field Elements

Field Elements

Notes

Fields Notes

translucency_value

The translucency_value field specifies the proportion of light that can pass through the given <Colour> instance. For a <Translucency> instance with a <Translucency Control Link> component, the value of the translucency_value field is obtained from that <Translucency Control Link> component.