Graphics Programs Reference
In-Depth Information
Moving a clipped PBP is the same as using Relocate Project. That is, the model elements
maintain their relationship to the PBP, but the relationship of the PBP to the Survey Point
is changed.
Project Base Point: Unclipped
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Move the PBP.
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PBP values change relative to the Survey Point.
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Project-based spot coordinates change.
Model elements don't move.
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Unclipping the PBP essentially detaches it from the internal project origin. Moving the
unclipped PBP is only used to affect the values reported in spot coordinates set to the
project origin base. It does not have any effect on exported files.
Survey Point: Clipped
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Move the SP (Survey Point).
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SP values don't change.
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Shared spot coordinates change.
Model elements don't move.
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The clipped Survey Point represents the origin of the shared coordinate system. Moving
it is the equivalent of setting a new origin point. Use caution if you must move the shared
coordinates origin if linked models already exist in which the shared coordinates have
already been synchronized. In such a case, each linked model must be opened and manu-
ally reconciled with the model in which the origin has changed.
Survey Point: Unclipped
◆
Move the SP.
SP values change.
◆
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Shared spot coordinates don't change.
◆
Model elements don't move.
Moving an unclipped Survey Point essentially doesn't do anything. It doesn't affect spot
coordinates and it doesn't affect the origin of exported files.
Use Pinning to Protect Coordinate Origins
an excellent way to prevent accidental modification of your project's coordinate systems is to pin them.
to do so, you must first make sure the survey Point and Project Base Point are visible in a view (as we
discussed previously in this section). next, select each point and click the Pin button from the Modify
panel when the Modify | Project Base Point or Modify | survey Point ribbon appears.
