paste surface

[stephen.cowling]

Hi all,
I have just spent ages trying to solve an error pasting surfaces, and then found this:
http://usa.autodesk.com/adsk/servlet...&siteID=123112
"If pasting surfaces fails, you can use an alternative method to paste the surfaces"

Anyone know when/why pasting surfaces can fail? I would MUCH rather have it working, as it is a lot of work to go through the method, and it removes the on-the-fly nature of the program.

[MHultgren]

Usually, when the Paste fails, it is due to a vertical (or near vertical) face in the two surfaces. I have seen it happen when you use the same boundary for both surfaces and one is not the same elevatioon as the other i.e. a cut or fill situation along the boundary. What I usually do is import my EG boundary, offset it .01 and then use that as my FG boundary. This will give me a sloped cut or fill line and as long as the slope is under 5 significant figures (integers only, no decimals), it usually works.

[stephen.cowling]

Thanks,
If that's the case then I've got no hope. I already made my existing ground substantially larger than the design and got nowhere, so I assume I've got small errors on the batters to existing which are causing vertical faces. Since the design is to be rebuilt automatically, I can't see a way around it.

[MHultgren]

Stephen,
Try placing wall faults along the areas that you have the vertical faces. LDT will create a "near vertical" face when it thinks it is a wall fault (something along the lines of a 15000% slope). Another thing to look for is crossing contours within either surface. Say you have a ditch and at the top of the ditch, the countours cross when it turns a corner, can cause problems too.

[stephen.cowling]

Let me get this straight. LDD (I assume you can't vouch for C3D) creates near vertical faces to avoid problems with vertical faces. These them cause problems with pasting surfaces, even though the model is built without problems?? Are you saying I should replace these near vertical faces with wall faults? What, then, is a wall fault?

Same thing with crossing breaklines - if the surface is buildable by LDD, why are there then problems later? Most of my models are built from triangles from other models created in another package which absolutely will not build a model until the crossing breaklines and vertical faces are dealt with manually, so I have not experienced this before.

Sorry to sound so stupid. I'm confused by Civil 3D more than by your post, and it's leading me to very complex conclusions to what is probably a fairly simple problem.

[MHultgren]

From the ADESK KB

http://usa.autodesk.com/adsk/servlet/ps/item?id=2887795&linkID=2475507&siteID=123112
ID TS49637 (I think you have already looked at this one)

Check your extended surface statistics and see what you max slope is. A breakline is different from a vertical face, don't ask me why. If I create a surface with 3D plines at my flowline and TC exactly vertical from each other, my surface will build, but I cannot paste it or manipulate it. If I offset the TC or flowline by .001 (horiz) then I have no problems. If I create a proximity breakliine for my TC or FL, again no problem (even when they are verical). When LDT creates the breakline, it actually does the minute offset when generating them. Draw a lpline and then make a breakline out of it. don't erase the object when prompted and then do a list and use a crossing window to select the (2) objects you created. Check out the coordinates for the objects. You may have to change you units precision to 6 or 7 decimal places to see the differences.

[doggarn.70892]

I went through hell trying to use the paste surface. I tried it with designing in a hillside
a railroad yard with split line tracks.... It was needless to say a designing challenge. I have to say after all the bull of the "paste surface" that it was much easier and faster to just go and use LINES that pickup the elev of a grading object or a 3d line and create a surface with the composite linework Not Polylines... then in the Terrain Explorer create a new surface with the 3d Polyline using entities.... grab the line that make up the composite of all your grading and you'll have the final surface and be able to get the volume calc's done in a fraction of the time by then comparing surfaces from og to the composite of your final lines (breaklines of finished surface). I had near vertical faces and if you try to build a surface with a vertical or near vertical you will almost always not be able to create a paste surface. Use the lines and trace over the grading object and use the 3d orbit if necessary to link the lines into what you know it should look like.... This technique is the fastest to solve vertical slopes or near to it.... DTM's are know for failing with points or lines on top of each other... always have and will be for along time to come...
Sometimes a paste will work, but the time to mend a DTM into a good model is better spent using the above method in my book.... again just another op's perspective

Mike in Alaska

[hingles]

sounds like you should use MAP to clean up those break lines.....
or get some training from this guy we used....(name ommited)