Autodesk 15606-011408-9320 - MAP R6.3 CPU MODEL-UPG 4/5 MIN 2 CPUS INITL, User Manual

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Chapter 5 Working with Data in Autodesk MapGuide
Differences in Clipping
VISION* supports a clipping primitive that is occasionally used to avoid
drawing in areas where annotations might later be drawn. For example,
when labeling a line, a clip area might be defined over the area where the
label will appear, creating a gap where the label will be drawn. Although lines
will be clipped by such a region, PostScript and TrueType fonts and polygons
will not be clipped. Therefore, some maps might display differently in
Autodesk MapGuide.
Primitives and Styles Simulated Using Polylines
To account for feature geometry and style model differences between
VISION* and Autodesk MapGuide, several primitives and styles will be simu-
lated in Autodesk MapGuide using polylines.
Scale-Dependent Symbology Displayed as Fixed
Some scale-dependent VISION* symbology (for example, line thickness) is
displayed in Autodesk MapGuide at a fixed scale. In this case, the scale will
be correct when the symbology is initially displayed in Autodesk MapGuide,
but as the user zooms, the lines will not get thicker.
Polygons Obscuring Non-Polygons
When a map has two or more VISION* theme layers, and the themes contain
features composed of polygon primitives and other feature types such as
annotations, some of the polygon primitives from the upper layers may
obscure the non-polygonal features and annotation from the lower layers.
You can reconstruct your VISION* cache using separate themes for polygons
and other feature types such as annotations, which will allow you to display
the polygons separately on a layer lower in the display order than the anno-
tation layer. You need to plan the display order of layers carefully, in order to
minimize the effect of features from upper layers obscuring those on lower
layers.