Civil 3D objects are complex. Labeling the Civil 3D objects is a great tool, because of the dynamic nature of the Civil 3D objects. However, such labels can bog down the performance of Civil 3D, especially in layouts (through viewports). This is particularly true of label groups for profiles and alignments. Label groups that this affects are:
- Alignment label groups
- Profile label groups
- Section label groups
- Profile view band label groups
- Section view band label groups
Surface labels also are controlled through these settings.
To alleviate this, Civil 3D has settings that control how the display of such labels are managed. These are available through two icons on the right side of the status bar, at the bottom of the Civil 3D screen.
(ToggleLabelVisibility) turns label visibility on and off for the whole drawing.
(AeccLabelOptimize) turns off the display of labels in specific label groups that are outside of the current model space display. Labels inside are unaffected.
The drop-down menu of AeccLabelOptimize offers the following options:
- Redraw when zooming/panning: Controls if labels are redrawn when zooming or panning, or only when required when the Civil 3D object containing the label changes.
- Label group level of detail: Controls whether fewer labels are shown when zoomed out from an object.
- Redraw label groups: If the Redraw when zooming/panning option is set, you can force label groups to be redrawn.
In addition, you can control label visibility in model space and paper space through the system variable AeccViewportOpt. This variable controls whether labels in paper space will be drawn if they are not within the extent of the viewport.
In the figure below, the upper portion displays the labels, the lower portion does not. Note however that the symbols for the labels (such as Spot Elevations) remain visible.