I'm trying to model a ditch. The default ditch will be 3:1 down from the shoulder for a depth of 1m, then 2:1 back up again. That's fine.
The problem comes where I have a target profile for the ditch. I'm looking for a subassembly that will hold the horizontal offset and steepen or shallow the slope as necessary. All the ones I've seen hold the slope and make the corridor wider or narrower.
I really need a Generic Link that will do "LinkOffsetAndVerticalDeflection". Why doesn't that exist?
Mark Green
Working on Civil 3D in Canada
My latest workaround was to use a copule of LinkOffsetAndSlope 's accros the top of the ditch and a LinkVertical down to find the bottom. Omit all those links. Mark the point at the bottom and then use LinkToMarkedPoint on both sides down to the bottom. I don't know if that can use a target, but I didn't even get that far.
Have a look at my assembly: ( I hand drew the cyan lines to show where the ommited links are, and I hand drew the blue lines to show where the LinkToMarkedPoint links should be, but they are showing up horizontal instead.)
And have a look at the corridor in the section editor. The ditch is showing up inside the lane to the right, instead of out to the left where it should be:
Mark Green
Working on Civil 3D in Canada
This sounds a bit odd. Without seeing a file I have some question.
Are you targeting both the alignment and the profile? Is the alignment holding the CL of bottom of ditch? Is the sub assm width set to match the offset to the target alignment? Can you post screen shots of your parameters and targets dialogs?
John Mayo
I was targeting a profile only, trying to use the sub to hold the offset. My next move was to create an offset alignment and target that, but I think I've found that LinkWidthAndSlope does what I need.
%Slope | May be used to override the fixed % Slope and tie the end-of-link to a profile. The following object types can be used as targets for specifying this: profiles, 3D polylines, feature lines, or survey figures. |
So far so good. I need to test that it is holding the right horizontal offset, but I think it is. I'd love to know what was wrong with the previous setup, but need to keep pushing on.
Thanks
Mark Green
Working on Civil 3D in Canada
John, I really appreciate the help, and sorry for denying you a chance to dig deeper into it and find the problem; I know you would.
Slight change of plan, the back of the ditch is just going to match existing ground (until the Engineer changes his mind again). I had a moment there when I couldn't figure out why there was no feature line showing up for the match point to add to my surface, then I realised it likely couldn't create the f-line until I set the target surface. So that worked.
On to the next problem...(good thing I gave this thread a generic title )
Here is my LinkOffsetOnSurface within the assembly:
And here it is in the corridor section editor: (dashed line is the surface it is targeting)
.....
And I think I figured it out. But it's weird.
The "Offset from Baseline" is actually constructed as an offset from the base of the assembly, but it is drawn as an offset from the insertion point of the sub. Although, I tested that with a DIST command when in the section editor, and it measured 2.2 something, not 2.058.
Anyway, I set the offset to 10.058 and it looks crazy wrong in the assembly, but builds it right in the corridor. Am I the only one who thinks this is madness?
Mark Green
Working on Civil 3D in Canada
No worries here. I am glad you have things moving along.
Yes it is strange. If your on subscription you may want to file a support incident.
John Mayo