Corridor surface building where there is no corridor

[bryan]

I have a corridor with gaps in between the regions where the intersections are. If I turn off all the intersection regions and rebuild my corridor, surfaces still bridge these gaps where there are no regions. Why would a surface exist where there is no corridor? Why are the surfaces bridging these gaps?

[Jeff_M]

Your corridor surface is still just a surface with point data in it. So it knows there are points on either side of that interection, but it has no way of knowing that it shouldn't connect those points in the TIN.

Set your surface definition Build options to use Maximum Trianle Length and specify a value that will prevent ging through the intersection:

[neilyj666]

Or you can draw a poIyline and add as a hide boundary to the surface definition

[brian.strandberg]

Or you can go into corridor properties, boundaries tab and add corridor extents as outer boundary.  This way the surface will not extend past the limits of the corridor.

Hope this helps!

[bryan]

I can't really put a boundary in the middle of a corridor when I need it to be one surface. Maybe this will clarify.

What intersection region looks like by itself:

What happens when all regions turned on:

Why do the two corridor regions left and right blow right through the intersection? 

[brian.strandberg]

Why don't you post the drawing?  I believe the idea I suggested will work.  Adding the boundary to the corridor properties does not restrict the surface from building there, just the corridor from building there.  

Hope this helps

[doni49]

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@Anonymous wrote:

Why do the two corridor regions left and right blow right through the intersection? 

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I've looked at your screenshots and don't believe it does.  The points and triangles are still there which is the really important part.

I too would like to see your dwg file.  Because it looks like the surface has been edited to flip/delete some triangles.

The way C3D does a surface is to connect triangles between three points and it normally connects the three NEAREST points (including points ALONG a breakline).  Then at elevation X along each side of a triangle, it draws a contour at elevation X.

So the question in my mind is why does C3D bypass the centerline points and instead triangulate to points that are NOT the nearest points?

[doni49]

Take a look at the attached screenshot.

[MikeEvansUK]

Reading your problem I think I can tell what's happening but can you clarify some things first please.

The behaveour you are having seems to sudgest a couple of things:

1. You have two seporate corridors one for the road and a second one for the Junction model. Is this correct?
2. The two seporate corridors have seporate surfaces defigned?
3. Either one of the surfaces has been added to the other as a pasted edit or both as a pasted edit into a seporate combined surface model?

If any of the above is correct then this is behaving exactly as expected.

The main road corridor has the gap between the two regions, the surface will triangulate between these regions (horizontally like in the image) .

I would expect that this model has been pasted in after (below) the junction. Thus the horizontal triangles are hiding the correct trianglulation in the second model.

There are a number of ways to clean this up.

• Add a manual surface boundary in a hide condition to the surface from the Main Corridor as stated previously by others.
• Manually Delete the triangles in this region using surface edits.
• Ensure that the surfaces are pasted in the correct order, Main corridor should be pasted into the surface first (at the top level).

My best advice is to remove the main road section from the junction model ending the junction model at the channel line (edge of road) then add the road element into the main corridor model terminating at the same channel line across the junction (i use conditional assemblies for the elimination of the footway) then the surfaces will be seamless when seporate or pasted.

M