why does the imported contour line NOT following the contour line!!!

[Richard McCarthy]

G'day Gang!

This is another one that's been bothering me as well...
When I imported the 3D contour lines from AutoCAD to make site topography, sometimes, the contour lines just REFUSE to conform the the shape of the imported contour line (it seems to intepolate/ have a mind of it's own) I tried to use different contour display intervals, and sometimes this method works, but sometimes it doesn't. This is especially frustrating because you KNOW some of the contour MUST pass certain points (critical part such as building edges) and it just isn't showing up and that makes the contour kinda useless.
Is there any way to FORCE Revit to confrom to the contour line??

(On a side note, I found this problem especially apparent when you have a "S" type contour line.. a "S" contour would usually mean that the same height contour points are bunched together and hence Revit would inteprete as a large area of plain and hence only contour the outline of this area)

I have also another question, is there any way to import point data? I get lots of spot elevational point data, and to manually put individual points in is a pain in the buttock..
.

[essdubbya]

Hi Richard
One of the frustrations of being unable to import point data easily into Revit is that there is no best method. If you choose to import contours you can get variable results due to the interpolation of an interpolation. Surveyors usually massage the data taken in the field due to the limitations of all survey software. Breaklines due to sudden changes of level etc can effect the results.
For this reason I usually steer clear of importing contours - also you get a heap of Revit points which slow down regrading of surfaces later in the design.
The only other way is to bring in points as a 2D drawing ie with the z coordinate removed and then create a surface using the imported drawing as an underlay.
In my case I download point data from a total station, reduce the levels to say AHD (Australian Height Datum) and import the point file into Autodesk Land Desktop. Then explode the points (to remove the z coordinates) and save as a dwg or dxf file for import into Revit. Time consuming maybe but at least I have a set of identifiable points which I have measured in the field and in which I have confidence. One other advantage is that I can build the toposurfaces as I go without worrying about contour lines agreeing with a surveyors interpolation. I also have spot levels where I want them such as building lines, fences, walls, drains (and inverts), kerbs etc.
In short, it's not easy but it works
Stephen Wallbank
3DL Baseplans

[Dean Camlin]

Richard, one way to "force" Revit to follow the established contour line is to do the interpolation for it by inserting additional fractional elevation ponts between the established lines. I find that nominal flat spots (those with meandering contour lines) tend to clean up this way.