Create Cropped Surface from Dref?

[AllenJessup]

Can you create a cropped Surface from a Surface created by pasting Dreffed Surfaces.

I get an "Error creating cropped surface" message each time I try. The command line looks like this:

Command: CREATECROPSURFACE
Select first corner or [Object/Polygon]: O
Select objects: 1 found
Select objects:
Select point in the area to crop:
Point (616864.92,861180.44,0.00)

The Point is the point I picked inside the closed polyline I pick as an Object. The boundary of that area highlights showing it has accepted that as the cropping boundary. I have also tried tracing the polyline point by point. The command line then shows all the points I picked.

Working in 2014 SP-1.

Allen Jessup


Civil 3D 2012 SP 3 / IDSP 2014
Dell Precision T7400, Xeon CPU 3.16 GHz
Win 7 Pro, 64-bit,12 GB RAM, Nvidia Quadro FX 4600

[AllenJessup]

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@Neilw wrote:

I haven't tried Allens suggestion of pasting a paste into a new surface.

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Well. It was really Mikes suggestion. I just confirmed it works. I now have a cropped Surface in a new drawing. From reading Help on the subject of Cropped Surfaces. It looks like there is still a link to the original surface but it doesn't work quite like a Dref. Also, since the cropping takes place from a pasted surface. You might have to go back a couple Surfaces and then bring any edits forward to initiate a change in the cropped Surface. I haven't tired it.

Allen

[AllenJessup]

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@doni49 wrote:

It hadn't sunk in that you were promoting it -- in essence removing the dynamic link.

Thanks for helping me understand and sorry for hijacking your thread.

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I'm not technically promoting. Only pasting into what we've been calling the dummy surface. A pasted surface should maintain a link to the original surface. I haven't figured out what the double pasting and cropping will do. Help suggests that a link is maintained between the cropped Surface an the Surface it was cropped from. Not exactly a Dref. I did notice that in the new drawing that not only was the cropped Surface create. But some of the original small Surfaces that the crop line crossed were also created in the new drawing. That makes me think that if the original smaller Surfaces were  edited, the cropped Surface would be updated. I haven't tried that yet.

No problem about hijacking. We're all talking about the same thing and trying to learn. Besides. In some circles EE's are notorious for hijacking threads.

Allen

[Neilw_05]

I'm confused about the workflows being presented here. I thought the goal was to create a clipped DREF, not a new surface. Is that what the end result is?

[AllenJessup]

My goal was to create a Cropped Surface from a large Surface that had been created by pasting in Dreffed Surfaces. I now want to paste in a Surface created from field work.

While ending up with a Surface linked to the original Surfaces would be nice. In this case it was unnecessary because the Lidar data wont change. So even a static Surface is fine for my use.

Allen

[Neilw_05]

Ahh, well then I totally misread your topic.

Sadly I'm still without a solution.

[AllenJessup]

I tried it and got an edit to follow through all the iterations except to the cropped surface drawing. While this doesn't provide a dynamic link through the whole process. It would only require the recreation of the final cropped Surface to show an edit to an original surface.

Allen

[Anonymous]

And yet I don't long for the days of Alidades, Statia and Plane Table (1995)

[Neilw_05]

As you have experienced, large datasets present a big challenge and the current point cloud technology is inadequate. I had hoped that a workaround would be to create a surface or a set of tiles from the raw data and store it. Then when we need to work on smaller areas of the site we could DREF the surface and clip it as needed. That clip boundary could be moved or expanded while working on a design or for exhibits, etc.

Thus a dynamic solution is needed.

[Neilw_05]

I finally took the time to run a test and as the help file says, the cropped surface will update to changes to the source. The key to getting it to update is to first use the Rebuild Snapshot command on the cropped surface, then Rebuild.

Try it. It should work.

[Neilw_05]

By the way, it is not necessary to use a DREF at all since the crop surface tool creates a new file or puts it in an existing file anyway.

So work from the file that has the live surface and apply the crop to it. The Crop won't effect the source surface at all, so you can skip the double processing with a DREF that Doni noted.