User manual

FastSCAN 15
3.3.2 Scanning Resolution - Limits Control
In some situations you may wish to place a limit on the resolution at which data is
collected, e.g. to reduce memory and processing requirements. This can be achieved
by adjusting the Best Scanning Resolution in the Scanner Limits Control dialog box
(accessed from Scanner/Limits Control).
You can control the coarsest scanning resolution at which data is collected via the
Worst Scanning Resolution in the Scanner Limits Control dialog box.
Use this to avoid inadequate
resolution when scanning very
quickly, in order to maintain a de-
sired accuracy and not miss im-
portant detail, or to avoid filling
in holes.
Selecting Wireframe from the
View menu will allow you to ex-
periment with different scanning
speeds and Best/Worst Scanning
Resolution values to assess the ef-
fect on resolution.
Figure 10: The Scanner Limits Control dia-
log box.
3.3.3 Profile Smoothing
The FastSCAN
TM
program filters and applies a degree of smoothing to each profile
during collection. This filter removes noise and errors in the scanner data, but can
also remove surface detail. A high value will remove a larger amount of detail while
a low value will preserve detail where it is present but tend to give a rougher surface.
A side effect of the profile smoothing is that some points are lost from the ends of each
profile. If the data has a gap in it (as might occur when scanning a hole in a surface)
then points are also lost from both sides of the gap. Higher smoothing values increase
the number of points lost.