NAME

DoTextureMapTranspIntens − Create a transparent intensity texture map primitive attribute object

SYNOPSIS

C:

DtObject DoTextureMapTranspIntens(operator,
mapping, raster)
DtMapOperator operator;
DtObject mapping;
DtObject raster;

FORTRAN:

INTEGER∗4 DOTMTI(OPRATR, MAPPNG, RASTER)
INTEGER∗4 OPRATR
INTEGER∗4 MAPPNG
INTEGER∗4 RASTER

DESCRIPTION

DoTextureMapTranspIntens creates a primitive attribute object that specifies a texture map for transparent intensity. 

Texture mapped primitive objects can be affected by more than one DoTextureMapTranspIntens attribute.  The parameter operator specifies whether subsequent primitive objects will be affected by this transparent intensity texture only, or also by other transparent intensity textures higher up in the scene hierarchy.  The possible values for operator are:

DcMapReplace <DCMR>
Any transparent intensity textures already defined will be ignored by subsequent primitive objects.

DcMapAdd <DCMADD>
Use this texture in addition to the transparent intensity textures higher up in the hierarchy. In case of overlapping textures, the one that is defined closest to the primitive object affected by the textures will be evaluated first. Note that a primitive object can only be affected by textures above it in the hierarchy.

The parameter mapping specifies which mapping procedure to use.  Possible values for mapping are:

DcStdTableLookup <DCSTLU>
Use the default 2-dimensional tabular texture mapping method the renderer provides.

DcStd3dTableLookup <DCS3TL>
Use the default 3-dimensional tabular texture mapping method the renderer provides.

Renderer-specific mappings
Use any renderer-specific mappings documented in your Doré System Guide. 

The parameter raster contains the actual texture map data to be used by the texturing procedure.  raster is a handle to an object created with DoRaster <DORS>, or DoFileRaster <DOFRS>.  Only one channel of data is (usually) needed for mapping transparent intensity.  If the raster data is in the standard Doré format, the following convention is used.  For rasters of type DcRasterA <DCRA> the alpha channel is used.  For rasters of type DcRasterZ <DCRZ> the Z channel is used.  For rasters of type DcRasterRGB <DCRRGB>, DcRasterRGBA <DCRRA>, DcRasterRGBZ <DCRRZ>, and DcRasterRGBAZ <DCRRAZ> a single intensity value is calculated from RGB data for every pixel.  This value is then used as the map data.   Some texture maps also use the alpha channel (see DoTextureOp).  Note that some renderers may not adhere to this convention. 

DoTextureMapTranspIntens is a primitive attribute and is inherited by subsequent primitive objects, as are all primitive attributes.  Unlike most other primitive attributes though, DoTextureMapTranspIntens also inherits a set of attributes, i.e. the texture attributes.  The texture attributes specify things such as which set of primitive uv coordinates to use, how to extend a texture when the primitive uv coordinates extend beyond the limits of the texture, whether to apply a transformation to the primitive uv coordinates before applying the texture, etc.  The current values of the texture attributes are bound to the DoTextureMapTranspIntens object when it is executed during traversal.  Thus the texture attributes are only indirectly bound to the primitive objects. 

ERRORS

DoTextureMapTranspIntens will fail if raster is not a DoRaster object or a DoFileRaster object. 

[WARNING - invalid or deleted object]

SEE ALSO

DoFileRaster(3D), DoRaster(3D), DoTranspIntens(3D), DoTextureMapTranspIntensSwitch(3D), DoTextureUVIndex(3D), DoTextureUVWIndex(3D), DoTextureMatrixUV(3D), DoTextureMatrixUVW(3D), DoTextureScaleUV(3D), DoTextureScaleUVW(3D), DoTextureTranslateUV(3D), DoTextureTranslateUVW(3D), DoTextureExtendUV(3D), DoTextureExtendUVW(3D), DoTextureOp(3D), DoTextureAntiAlias(3D)

September 02, 1992