If you've ever read any of my posts before, you know I'm a staunch believer in NEVER exploding any Civil 3D entities. I have a trail project that I am designing now, one started several years ago before I was working at this company. The survey is from another company, and since the survey was done more than 10 years ago (yes, I know) I believe that it was done using Land Desktop. This other company is pretty much washing their hands of this, and I have no problem with that since I don't think their original survey was intended to be a design topo survey for a trail project. When I first started working on this trail, it was already started, including P&P sheets and cross sections. My boss asked me to get familiar with it, and I compiled a list of questions and concerns I had regarding the project, and specifically the survey. One of those concerns was the accuracy of the existing ground surface. I believe that somebody from this company, no longer here, created the surface from contours shown on this provided survey, which are in layers prefixed with Aerial-*. All this was from at least 8 or 9 months back.
Now my boss has keyed in to an area where the contours are obviously wrong, crossing back over themselves and creating a stair stepped EG profile. He's asked me to spend more time looking at it and trying to massage the surface to something more visually pleasing. We have a Design Base drawing, and the EG surface is a data shortcut from a Topo Base drawing. The Topo Base drawing has an EG surface. I look at my contours, but they are polylines. I tell my boss that the contours can't be that surface, because a Civil 3D surface doesn't create polylines. The EG surface is set to 1' and 5' contours, so I change it to 0.2' and 1' contours so I can be sure to know which entity is actually the Civil 3D surface. Nothing happens. Thaw and turn on all layers and still nothing. I erase one of the polylines and my EG surface is marked as out of date in my Prospector. Okay, it looks like somebody probably exploded the surface. Not ever having done this, even by accident, I am clueless as to what the ramifications are of having this exploded surface.
For S&G, I edit the surface to add a point at elevation 1000, 200' above my surface. Nothing changes. Can a surface that has been exploded be modified? I just displayed my triangles and points, and they are still intact. The point I added at elevation 1000 is shown as being at elevation 1000, even though contours are not populating. I'm just scratching my head trying to figure out if it will be worthwhile for me to try to edit the surface, since apparently the contours will not change. Maybe I could live with a surface that was technically correct but not contoured correctly, but does anyone know if my EG profiles and cross sections will dynamically update? I'm not even sure I could do a good job of editing the surface, since the contours are what would give me verification that my editing is correct. Can you get back dynamic contours from a Civil 3D surface after it has been exploded? Would it be a good idea to maybe try to XML out the surface and then bring it back in?
Again, this is uncharted waters for me, so perhaps someone can share insight. Thanks in advance for any suggestions or ideas.
Create a surface from the contours. Pick a contour then right click select similar . Under definition contours right click add.
A surface in C3d is a drawing object. If you explode it, it ceases to exist. Nevertheless your data link still exists.
For contours to cross some crazy contour smoothing must have been applied. Creating a surface from contours that were smoothed to the point of crossing isn't going to be useful at all.
Do you have the TIN lines? A surface could be made up using those as data.
Mark Mayer, post: 424436, member: 424 wrote: A surface in C3d is a drawing object. If you explode it, it ceases to exist. Nevertheless your data link still exists.
For contours to cross some crazy contour smoothing must have been applied. Creating a surface from contours that were smoothed to the point of crossing isn't going to be useful at all.
Do you have the TIN lines? A surface could be made up using those as data.
After I posted this morning I did some more poking around. Like you say, if the surface had been exploded, it disappears from Prospector. I'm thinking that maybe the contour lines were extracted from the surface to create the polylines, another thing I've never done, but that wouldn't explain why I couldn't manipulate the actual surface contours.
I didn't even think about the contour smoothing. I think you're right about that. They were probably splined. There were no TIN lines, other than the triangles in the surface. Have you ever extracted the triangles from a surface? I think I'd be leery of doing that though, because I think the substantial editing that needs to be done is swapping edges on the triangles.
We were able to get a point file. It's not comprehensive because I think the surveyor only filled in gaps, leaving me with about 800 points over the three mile project. I'm going to try to incorporate those points into the surface tomorrow.
Thanks Mark. I always appreciate your insight.
BlitzkriegBob, post: 424317, member: 9554 wrote: I just displayed my triangles and points, and they are still intact.
If the triangles are 3dfaces you can simply build the surface from AutoCAD objects - be sure to check the maintain edges checkbox. You'll have the exact same surface except there may be differences at the boundary(ies).
If the triangles are 2d lines they won't help.
If the triangles are 3d lines you can build it from them.
If the triangles are part of a surface and the surface is just corrupt, you can try extracting the 3DFaces from the surface - (from memory so...) With the triangles showing using the drop down menu: surface - surface utilities - extract objects - this will give you the 3DFaces from the surface and you can build a new, clean surfaces.
No matter what - when you have the objects that you'll use to build a new surface, wblock them to a new drawing so that you can ditch whatever problems are in the old drawing.
JKinAK, post: 424440, member: 7219 wrote: If the triangles are 3dfaces you can simply build the surface from AutoCAD objects - be sure to check the maintain edges checkbox. You'll have the exact same surface except there may be differences at the boundary(ies).
If the triangles are 2d lines they won't help.
If the triangles are 3d lines you can build it from them.
If the triangles are part of a surface and the surface is just corrupt, you can try extracting the 3DFaces from the surface - (from memory so...) With the triangles showing using the drop down menu: surface - surface utilities - extract objects - this will give you the 3DFaces from the surface and you can build a new, clean surfaces.
No matter what - when you have the objects that you'll use to build a new surface, wblock them to a new drawing so that you can ditch whatever problems are in the old drawing.
The triangles are just part of the surface. Extracting them is just what I was wondering about after reading Mark's response. I've never done it, but maybe this is a good time for a first. I might try this tomorrow also.
Here's a new question. I was a little hesitant to create a new surface since the original was already a data shortcut, and was being used in the profiles, cross sections, and the corridor. I'd have to rebuild everything if I created a new surface, but...if I give the surface the same name as the original surface, would all my references stay intact? What would the steps be? If I just delete the original surface from the source drawing, will that wipe out the shortcut immediately? What if I rename the original surface to something else, then assign the original surface name to the new surface? Would the shortcut still point to the original (now renamed) surface, or would it honor the original name and point to the new surface? Well that's more than one question, but my mind is racing as I'm typing.
Exploding a surface object ceases its 3D intelligence. It ceases being a Civil 3D object. I don't understand why you need to explode the surface object in order to control and manage the surface you're dealing with. You have ways of doing it if you need to play around. You can readily extract AutoCAD objects from Civil 3D surface object if you want to without necessarily disturbing the parent surface object. I think this is fairly manageable.
If you have the TIN lines - the triangles - import them as breakline data. You will get a perfect duplication of the original surface.
amdomag, post: 424446, member: 1683 wrote: Exploding a surface object ceases its 3D intelligence. It ceases being a Civil 3D object. I don't understand why you need to explode the surface object in order to control and manage the surface you're dealing with. You have ways of doing it if you need to play around. You can readily extract AutoCAD objects from Civil 3D surface object if you want to without necessarily disturbing the parent surface object. I think this is fairly manageable.
I didn't explode it. I inherited this surface. Like I said at the very beginning, I NEVER explode anything Civil 3D. Lots of people seem to like doing that though.
Mark Mayer, post: 424447, member: 424 wrote: If you have the TIN lines - the triangles - import them as breakline data. You will get a perfect duplication of the original surface.
Probably dealing with semantics here, but when I talk about triangles, I mean the triangles that are created as part of a Civil 3D surface. I don't have any TIN lines that are independent of the surface.
BlitzkriegBob, post: 424449, member: 9554 wrote: I didn't explode it. I inherited this surface. Like I said at the very beginning, I NEVER explode anything Civil 3D. Lots of people seem to like doing that though.
I see. Can you post some screenshots?
BlitzkriegBob, post: 424450, member: 9554 wrote: Probably dealing with semantics here, but when I talk about triangles, I mean the triangles that are created as part of a Civil 3D surface. I don't have any TIN lines that are independent of the surface.
If you have such triangles than you do have a surface. Probably your surface style is set to not display contours. Edit the style.
Mark Mayer, post: 424465, member: 424 wrote: If you have such triangles than you do have a surface. Probably your surface style is set to not display contours. Edit the style.
That was the first thing I checked. It was set to display contours.
amdomag, post: 424459, member: 1683 wrote: I see. Can you post some screenshots?
Image 1 is what the contours look like. I'm showing a sample area, not a contour problem area. The yellow line at the bottom is the surface boundary. Anyone who has used C3D knows if you select a part of the surface, the entire surface gets selected, not just one contour. Also note in the properties box that the entity is indeed a polyline. Resides in layer as shown at upper left.
Image 2 shows what I have when I pick freeze the aerial contour layers. Now I have no contours, but I do still have my surface boundary.
Image 3 shows my surface style, which is set to display contours.
Image 4 shows that if I set my triangles to display, they do indeed display.
I also checked to make sure that layer 0 was not frozen. I personally would have set layers within my surface style for the contours, instead of leaving everything on layer 0. The surface entity itself resided on one of the aerial contour layers, but I changed that to also be on layer 0 and that did not help.
amdomag, post: 424459, member: 1683 wrote: I see. Can you post some screenshots?
Here are some examples of contours that are obviously wrong.
I work with CAD files like this very often. There are many tricks to extracting a decent surface from the DWG. Feel free to forward the DWG to "lee at leegreen.com" and I'll take a quick look. I use several different software packages including Carlson TakeOff, and InRoads that have routines for extracting the surface.
