Marker Attributes

For an overview, see Primitives and Attributes.

A marker is a two-dimensional glyph, or symbol, representing a location in three-dimensional space. Use modeling coordinates to specify the marker's position. As with other output primitive coordinates, PEXlib transforms the position within the rendering pipeline. When your application enables depth-cueing, a marker's color is affected by the depth-cueing computation. However, a marker has no surface from which to reflect light, therefore, the light-source illumination stage of the rendering pipeline has no effect on markers.

The attributes that affect marker primitives are:

 
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Marker Bundle Index OC              PEXOCCSetMarkerBundleIndex
      Marker Color OC (ASF)         PEXOCCSetMarkerColor
      Marker Color Index OC (ASF)   PEXOCCSetMarkerColorIndex
      Marker Scale Factor OC (ASF)  PEXOCCSetMarkerScale
      Marker Type OC (ASF)          PEXOCCSetMarkerType
Marker Bundle Table RA              Marker Bundle Table (LUT) and
                                       Marker Bundle Table (Renderer)
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The PEXlib marker primitives affected by the above attributes include:

 
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Marker 3D  PEXOCCMarkers
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See the sections referenced above for information about each of the marker primitives and the attributes that affect them.

Clipping of Markers

Clipping is performed according to the marker position. If your application positions the marker outside of the clipping volume, then the server does not render any portion of the marker glyph. Clipping of portions of marker glyphs that extend beyond the clipping volume is implementation-dependent.

HLHSR (Hidden Line/ Hidden Surface Removal) of Markers

The treatment of markers during hidden surface computations depends on the HLHSR (Hidden Line/Hidden Surface Removal) mode you select and its implementation. Z-buffer algorithms usually perform the hidden surface computation on the realization of marker glyphs. Scan-line algorithms may determine visibility for markers solely from the 3D position of the marker.

Marker Bundle Index and Marker Aspect Source Flags

Whenever you render a marker primitive, each of the marker attributes is obtained directly from the current pipeline state or indirectly from a marker bundle lookup table. Your application determines the source for the attribute by the current settings of the marker aspect source flag or ASF's. If your application sets an attribute's ASF to the value PEXIndividual, then your application obtains the attribute value directly from the current pipeline state. If your application sets an attribute's ASF to the value PEXBundled, then your application obtains the attribute value from the current marker bundle lookup table. The marker bundle index attribute indicates the marker bundle table entry to be used.