Topic: Marked Point

[sinc]

I'm trying to understand this subassembly.  I've gotten it to work, for example I successfully modeled a ditch between two alignments with profiles using the "Link Slopes Between Points" subassembly.

But the way I did it was to use the "Link Offset and Elevation" subassembly.  I attached that subassembly to my assembly, which was attached to the 1st alignment/profile.  The Marked Point subassembly was attached to the far end of the "Link Offset and Elevation" subassembly.  Then I attached the "Link Slopes  Between Points" subassembly to my assembly, and hooked it to the Marked Point.  I also deleted the "Top" and "Datum" link codes from the "Link Offset and Elevation", so that no surface would get created from that link.  This correctly modeled my ditch, with something that maintained a ditch with constant width and slopes from both alignments and profiles.

Is this a common way this subassembly is used?  With something like "Link Offset and Elevation" as a sort of "calc link" to place a "Marked Point" on another alignment/profile, so that subassemblies like "Link Slopes Between Points" have something to hook to?

There was something else that confused me.  It's something Michael Farrell said:

2008 - MarkPoint
 
 
This subassembly is used to mark an existing point on the assembly with a name.

This is usually done so that other subassemblies can later insert links that attach back to this point (for example, LinkToMarkedPoint). The attachment point is the point that is marked. You can add user-defined point codes to this marked point.

How about clearly adding the Rules and Behavior of the little gem in the Help file for it?
Like the fact that the Marked Point and the object looking for it must be attached to the same Assembly 'baseline' or offset group, and that it will not cross over the Centerline?

I'm not sure I get that part about it not crossing the centerline.  I was able get it to work, even when I wove the alignments around each other.  The only thing I had to do was go into the Assembly properties and make sure that the Marked Point was listed above the subassembly that referenced it.

[mjfarrell]

SINC, the 'doesn't cross centerline' is related to the Median Subassembly, note in the Help file that it may require 3 cases. From Help: The alignment defining the edge of the median may at times be either not present (Case 1), outside the roadway centerline (Case 2), or inside of the centerline (Case 3). To use this subassembly you should have separate alignments defining the left and right edges of the median. It may be necessary to define separate corridor model regions for each individual median. This is alluded to in a couple of the corridor modeling presentations as shown in the Webcasts.

When using these 'calced links' think of them as a place holder. Also be sure to set the dummy link, links' properties to Do Not Display, this will make viewing the corridor model clearer. From Help: MarkPoint
This subassembly is used to mark an existing point on the assembly with a name.

This is usually done so that other subassemblies can later insert links that attach back to this point (for example, LinkToMarkedPoint). The attachment point is the point that is marked. You can add user-defined point codes to this marked point.

I think you don't really want to remove Top, and Datum so that those surfaces ARE created so that you can get volumes, and sections from the model.

[Jeff_M]

You may find the webcast from Dec. 6 2006 quite helpful, Sinc.