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DTM won't calc Cut and Fill

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I have an existing and proposed DTM. When I run the Cut and Fill, it tells me, properly, that there's 0 change be/c there has been no site modification. I use the site modifier for the first time to create a pad and a control fence. The pad is completely within the control fence. I only have one of each. I update the proposed site model, and the results look good, except that the contour for my parking area (the pad) matches the shape of the pad modifier, but is 1' lower than its elevation. Why would that be? My contour interval is 1'....coincidence or not?

Then when I run Cut and Fill, I first get an "A miscellaneous error has occurred (20, 2)" error, and then "ERROR: Unable to create Cut and Fill DTM." So now I'm stumped and kinda dead in the water till I figure this out. Any ideas on how I got this result?


ps. The image-storing site has been flakey lately and might delay in drawing the picture. I think it depends on the position of the moon or something.

Notice how the red-line for the Pad site modifier is one contour above the pad that was created. Or at least that's my interpretation of what I'm seeing. I've been wrong before. [smile]

[ 08-25-2003, 10:43 AM: Message edited by: Cloud Hidden ]

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Don't believe so. When I created it, the actual highest elevation was 50' and lowest was -50', and both existing and proposed still show that. When I view the model in front view, I have a bottom contour that properly touches -50 on its bottom edge, but the top of the top contour only is 49. Send to surface places an object at 50' elevation, leaving a 1' gap. I can certainly set my pad's one foot higher than I want them to make it look right. Which raises another point--the gap is always the contour interval...1', 2', whatever interval I use for the contours. That speaks against having dropped the DTM by a fixed amount. Somewhere, it seems a contour layer is missing and I still don't grok DTM enough to guess where it went.

On the cut-and-fill, I switched from curved pads and fences to rectilinear ones so I could more easily try your suggestions on tiered pads. Cut-and-fill no longer gave error message and seemed to work as advertised. The error only happens when I use the cubic vertex mode (didn't try the other curved modes) for creating pads.

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"anomoly"....you once worked for Microsoft, right? --Just kidding! In my software company, things like this were called #&%*!$% [smile] --

I had never before used the 3D Triangle....guess I just liked the look of the 3D Contours for some strange reason....but I tried it here. With the single only change being a trip to AEC->DTM Processor->View Options and unchecking the one and checking the other, the model draws properly, with the top surface matching the pad site modifiers rather than sitting one contour level below them.

Thanks for following up on this.

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Even at 1'....heck, even at 2'.....I was getting a message that the interval was small compared to the range. But even at an inch, I'd still have a shadow line where the contour was 1" lower than expected. So I'll either offset the pads or use the triangles. Heck, maybe I'll even try to make a nurbs surface follow the curves of the ridgeline....that oughta be fun!

Knowing that contour thing is an anomoly and knowing that cut-and-fill works better with rectilinear pads than curved ones, I can make the adjustments here for now. Hopefully, it's also good feedback to NNA for a future VW version.

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I am curious. If you select the pad object and look at the object info pallet there is a Z height field and an elevation field. Is the Z height field 0 and the elevation field set to the correct elevation for the pad object?

If you set the Z height to -1 and the elevation to -1 the pad will modify the grade to -2 (or 1 unit below what you are expecting)

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