Table 6.114 — DRM_Image_Lookup

Property

Description

Class
  • <DRM Image Lookup>

Superclass

Subclass
  • None.

Definition

An instance of this DRM class specifies a set of data representing the final displayed value of a texel.

The value of a texel no longer represents the colour at a point on a display; instead, a texel value is interpreted as a reference into the lookup representing the final displayed value.

In general:

  • The number of axes in a lookup equals the number of components within the referencing image signature.

  • The number of elements along an axis equals the maximum size of the component image data.

The min / max field values are used to specify the minimum and maximum values the corresponding texel component may have. For example, if the lookup components are floating point 32 bits, then a minimum value of -1.0 and a maximum value of 1.0 means that all values in the referenced <DRM Image> instance fall within the range [-1.0, 1.0]. In another example, a lookup with unsigned integer texel components of 8 bits may specify its range to be [0, 99], indicating that even though the maximum value that can be specified with 8 bits is 255, the value 99 should be treated as the maximum value for this lookup.

Class diagram

Figure 6.134 — DRM_Image_Lookup

Inherited field elements

Field name

Range

Field data type

None

    

Field elements

Field name

Range

Field data type

lookup_signature

 

Image_Lookup_Signature

lookup_type

 

Image_Lookup_Type

colour_model1

 

Colour_Model

data_is_integer2

 

Boolean

bits_of_alpha3

 

Short_Integer_Unsigned

bits_of_luminance4

 

Short_Integer_Unsigned

bits_of_colour_coordinate_15

 

Short_Integer_Unsigned

bits_of_colour_coordinate_26

 

Short_Integer_Unsigned

bits_of_colour_coordinate_37

 

Short_Integer_Unsigned

bits_of_bump_map_height8

 

Short_Integer_Unsigned

bits_of_material_19

 

Short_Integer_Unsigned

bits_of_material_210

 

Short_Integer_Unsigned

bits_of_material_311

 

Short_Integer_Unsigned

bits_of_material_2_percentage12

 

Short_Integer_Unsigned

bits_of_material_3_percentage13

 

Short_Integer_Unsigned

bits_of_image_index14

 

Short_Integer_Unsigned

bits_of_bump_map_u15

 

Short_Integer_Unsigned

bits_of_bump_map_v16

 

Short_Integer_Unsigned

min_value_of_alpha17

 

Float

max_value_of_alpha18

 

Float

min_value_of_luminance19

 

Float

max_value_of_luminance20

 

Float

min_value_of_colour_coordinate_121

 

Float

max_value_of_colour_coordinate_122

 

Float

min_value_of_colour_coordinate_223

 

Float

max_value_of_colour_coordinate_224

 

Float

min_value_of_colour_coordinate_325

 

Float

max_value_of_colour_coordinate_326

 

Float

min_value_of_bump_map_height27

 

Float

max_value_of_bump_map_height28

 

Float

min_value_of_bump_map_u29

 

Float

max_value_of_bump_map_u30

 

Float

min_value_of_bump_map_v31

 

Float

max_value_of_bump_map_v32

 

Float

axis_size33

 

Short_Integer_Positive

axes_count34

 

Short_Integer_Positive

Associated to (one-way) (inherited)
  • None.

Associated to (one-way)
  • None.

Associated by (one-way) (inherited)
  • None.

Associated by (one-way)
  • None.

Associated with (two-way) (inherited)
  • None.

Associated with (two-way)
  • None.

Composed of (two-way) (inherited)
  • None.

Composed of (two-way metadata) (inherited)
  • None.

Composed of (two-way metadata)
  • None.

Component of (two-way) (inherited)
  • None.

Component of (two-way)

Constraints

Clarifications

1 This is the colour model used throughout the lookup. Only one colour model is allowed per texture definition.

2 This flag describes the data type of the raw lookup data. Either the raw data is integer and the data max sizes are valid, or the raw lookup data is floating point and the values are between 0 and 1.

3 If 0 is specified, the lookup data does not contain alpha information.

4 If 0 is specified, the lookup data does not contain luminance information.

5 If 0 is specified, the lookup data does not contain colour information for this colour coordinate (R, C, H).

6 If 0 is specified, the lookup data does not contain colour information for this colour coordinate (G, M, S).

7 If 0 is specified, the lookup data does not contain colour information for this colour coordinate (B, Y, V).

8 If 0 is specified, the lookup data does not contain bump_map_height information.

9 If 0 is specified, the lookup data does not contain material 1 index information; otherwise, this is an index into the <DRM Property Table> instance that is referenced from the given <DRM Image> instance.

10 If 0 is specified, the lookup data does not contain material 2 index information; otherwise, this is an index into the <DRM Property Table> instance that is referenced from the given <DRM Image> instance.

11 If 0 is specified, the lookup data does not contain material 3 index information; otherwise, this is an index into the <DRM Property Table> instance that is referenced from the given <DRM Image> instance.

12 If the <DRM Image> instance being referenced by the given <DRM Image Lookup> instance contains material 2 information, this field value is the percentage of material 2.

13 If the <DRM Image> instance being referenced by the given <DRM Image Lookup> instance contains material 3 information, this field value is the percentage of material 3.

14 If 0 is specified, the lookup data does not contain image index information.

15 If 0 is specified, the lookup data does not contain bump_map_u information.

16 If 0 specified, the lookup data does not contain bump_map_v information.

17 This is the minimum value that alpha can be within the lookup data; it is 0.0 if not used.

18 This is the maximum value that alpha can be within the lookup data; it is 0.0 if not used.

19 This is the minimum value that luminance can be within the lookup data; it is 0.0 if not used.

20 This is the maximum value that luminance can be within the lookup data; it is 0.0 if not used.

21 This is the minimum value that colour_coordinate_1 can be within the lookup data; it is 0.0 if not used.

22 This is the maximum value that colour_coordinate_1 can be within the lookup data; it is 0.0 if not used.

23 This is the minimum value that colour_coordinate_2 can be within the lookup data; it is 0.0 if not used.

24 This is the maximum value that colour_coordinate_2 can be within the lookup data; it is 0.0 if not used.

25 This is the minimum value that colour_coordinate_3 can be within the lookup data; it is 0.0 if not used.

26 This is the maximum value that colour_coordinate_3 can be within the lookup data; it is 0.0 if not used.

27 This is the minimum value that bump_map_height can be within the lookup data; it is 0.0 if not used.

28 This is the maximum value that bump_map_height can be within the lookup data; it is 0.0 if not used.

29 This is the minimum value that bump_map_u can be within the lookup data; it is 0.0 if not used.

30 This is the maximum value that bump_map_u can be within the lookup data; it is 0.0 if not used.

31 This is the minimum value that bump_map_v can be within the lookup data; it is 0.0 if not used.

32 This is the maximum value that bump_map_v can be within the lookup data; it is 0.0 if not used.

33 This is the number of elements along each axis of the lookup. All axes shall be the same size and shall be as large as any maximum value for any component within the referencing <DRM Image> instance.

34 This is the number of axes within the lookup, and shall coincide with the lookup_signature of the given <DRM Image Lookup> instance.

Example(s)

  • Given an <DRM Image> of a regular grid of lines, by scaling the <DRM Image>, it can be used to represent the concrete blocks of a parking lot, and by having an <DRM Image Lookup> change the alpha of the “white” areas of the grid, the <DRM Image> can be applied to a vertical <DRM Polygon> in order to represent a chain link fence.