The SEDRIS Data Representation Model
APPENDIX B - Constraints
Colour Mapping Constraints

Definition

The colour_mapping field of a <Colour> instance shall not be empty.

In addition,

  1. The Primary_Light_Rendering_Behaviour and Secondary_Light_Rendering_Behaviour flags may only be used for DRM objects with <Light Rendering Properties> components.

  2. The Primary_Light_Rendering_Behaviour flag may not be combined with any other use of the SE_Colour_Mapping data type.

  3. The Secondary_Light_Rendering_Behaviour flag may not be combined with any other use of the SE_Colour_Mapping data type.

Rationale

A <Colour> instance specifies how it is applied to the DRM objects that use it, so its colour_mapping shall not be empty.

The Primary_Light_Rendering_Behaviour and Secondary_Light_Rendering_Behaviour flags specify the primary and secondary colours of the <Light Rendering Behaviour> component(s) of a <Light Rendering Properties> instance.

If a <Colour> instance C applies to the <Light Rendering Behaviour> component(s) of the <Light Rendering Properties> component of a DRM object rather than the DRM object itself, C shall apply only to the <Light Rendering Behaviour> component(s). In addition, the same <Colour> instance cannot be both the primary and the secondary colour of a <Light Rendering Behaviour> instance.

Example

  1. Consider a <Polygon> instance with two <Inline Colour> components and an <Image Mapping Function> component, where the image_mapping_method of the <Image Mapping Function> component is set to SE_IMAGMAPMETH_BLEND.

    Each <Inline Colour> component shall specify whether it is PRIMARY, IMAGE_BLEND, or neither, and which side of the <Polygon> instance is affected, in order to indicate how to combine the colours with the texture.

FAQs

See the <Colour> class, SE_Colour_Mapping, and the <Image Mapping Function> class for discussions of how colour_mapping is interpreted.


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