Jeff Morris | Sr Applications Expert
Pipes & Structures
A gravity pipe-network in AutoCAD Civil 3D consists of one or multiple branches of pipe runs. The individual pipes are connected via structures (Null or otherwise). As the structure location changes, the pipes remain connected.
Structure Styles
Structures can represent different objects, such as catch basins, manholes, headwalls, etc. In order to distinguish catch basins from manholes, a different style is used for the structure, although the structure itself may not change. These structure styles can conform to the organizations graphic standards for said manholes or catch basins.
If blocks are being used to define the style, Civil 3D places a mask under the block so the connecting pipes are not shown within the structure – i.e. masked out. More often than not, these styles are “annotative”, meaning they will change size as the annotation scale changes, much like the Civil 3D labels change size.
Changing Annotation Scales
When one changes the Annotation Scale in Modelspace of Civil 3D, these masks don’t update and either gaps or overlaps between the pipes and structures appear. Even in Paperspace, the gaps / overlaps carry over, regardless if the viewports are locked or not!
The regular fixes such as the Regen or Regenall or even Redraw don’t work, the overlaps remain. One cumbersome fix is to select a structure and SLOWLY doubleclicking on the square grip in the middle of the structure (usually used to move the structure).
This will resize the mask, but must be done on each structure.
The other option is to invoke the Audit command. By agreeing to “Fix any errors detected?” [yes], all gaps or overlaps will be corrected. If one chooses not to fix detected errors, the gaps/overlaps remain!
Keep in mind however that auditing a drawing can take a long time.
Conclusion
Even though this behavior between pipes and structures when changing annotation scales in Modelspace is annoying, two fixes are available.
Without these fixes, these gaps / overlaps will plot as it is displayed on the screen (Modelspace or Paperspace).
Thus even more reason to audit your Civil 3D drawing regularly, especially before you plot!
Could you just not define the block itself as having a hatch that uses a background colour (e.g. 255,255,255). That way it will wipe out the structure automatically. (Okay, you may need to bring your structures to the front)
Would this solve it?
Posted by: NathanBee | 09/13/2017 at 06:32 PM
Sometimes a quicker way to fix the issue is to edit the structure style and click OK (without needing to change anything). This will force C3D to recalculate the masks for all structures using that style.
The drawback is that it will need to be done for each style.
Posted by: TimStalin | 09/14/2017 at 09:09 PM
we do like @NathanBee, but every now and then blocks used in C3D styles somehow get confused with last drawn entity and you have to remind it by block editing the symbol and copying\create new line work and removed previous linework.
We have a -msk layer and set the pen color to not plot in the ctb. We can see the mask on screen, but it wont plot. At one time our Kip plotter wouldn't work with wipeouts and C3D's background masks. It was just blobs of black.
Posted by: Jeremy Nelson | 09/21/2017 at 05:08 PM