TKE_Texture
Opcode
ASCII |
t |
Hexadecimal |
74 |
Decimal |
116 |
Operands
Byte name_length, (name_length)xByte name,
Byte image_length, (image_length)xByte image_name,
Short options, [Byte parameter_source], [Byte tiling],
[Byte interpolation], [Byte decimation],
[Byte red_mapping], [Byte green_mapping],
[Byte blue_mapping], [Byte alpha_mapping],
[Byte param_function], [Byte layout],
[(2)xByte value_scale], [Byte transform_length],
[(transform_length)xByte transform_segment]
| name_length | length of texture name string |
| name | name of texture |
| image_length | length of image name string |
| image_name | name of image on which the texture is based |
| options | flags indicating optional fields |
| parameter_source | initial values used for texture lookup, usually UV parametric values |
| tiling | indicates how parameter values outside the 0-1 range are handled. |
| interpolation | indicates texture sampling when a texture pixel spans multiple display pixels |
| decimation | indicates texture sampling when a display pixel covers multiple texture pixels |
| red_mapping | enumeration of source choices for red value |
| green_mapping | enumeration of source choices for green value |
| blue_mapping | enumeration of source choices for blue value |
| alpha_mapping | enumeration of source choices for alpha value |
| param_function | initial remapping function for parameter values |
| layout | arrangement of useful picture data within the image |
| value_scale | amount to scale and shift color values |
| transform_length | length of transform segment name |
| transform_segment | name of a segment containing an additional texture_matrix to apply |
Notes
Textures define a form of image which can be stretched and applied to a surface. The simplest form is indeed just an image; as each pixel on the surface is drawn, a color is selected from a corresponding spot on the image. The options allow for changes to the correspondence between points, and/or changes to the color selected.
For the specific definitions on what the various texture option bits mean in HOOPS/3dGS please refer to the Define_Texture specification in the 3dGS Reference Manual.
Option bits
| 0001 | Parameter Source |
| 0002 | Tiling |
| 0004 | Interpolation |
| 0008 | Decimation |
| 0010 | Red Channel Mapping |
| 0020 | Green Channel Mapping |
| 0040 | Blue Channel Mapping |
| 0080 | Alpha Channel Mapping |
| 0100 | Parameter Function |
| 0200 | Layout |
| 0400 | Transform Segment Name |
| 0800 | Value Scale |
| 1000 | Caching |
Parameter sources
| 0 | U |
| 1 | UV |
| 2 | UVW |
| 3 | Object Space XYZ |
| 4 | World Space XYZ |
| 5 | Surface Normal |
| 6 | Reflection Vector |
| 7 | Natural UV |
| 8 | Local Pixels |
| 9 | Outer Pixels |
| 10 | Local Window |
| 11 | Outer Window |
Parameter functions
| 0 | None |
| 1 | Sphere |
| 2 | Cylinder |
| 3 | Box |
Parameter layouts
| 0 | Rectilinear |
| 1 | Spherical |
| 2 | Hemispherical |
| 3 | Cubic Faces |
Parameter tilings
| 0 | None |
| 1 | Clamp |
| 2 | Repeat |
| 3 | Mirror |
Texture filters
| 0 | None |
| 1 | Bilinear |
| 2 | Trilinear |
| 3 | MipMap |
| 4 | Summed Areas |
| 5 | Gaussian |
| 6 | Stochastic |
Channel mappings
| 0 | Red |
| 1 | Green |
| 2 | Blue |
| 3 | Alpha |
| 4 | Zero |
| 5 | One |
| 6 | Luminance |
| 7 | None |
