Certain features that are tied in the course of a topo won't have useful elevations on them. When I shoot a building wall using reflectorless, for example, the elevation on the point will be at some random height above ground, I care not what. Same for fences, trees, poles, fire hydrants,etc. Since the elevations on these things may not be valid, and in a given job some may be valid while others are not, I choose to not include any of them in my DTM. With F2f layerizing and grouping my points that's easy to do.
Even with these points excluded from the DTM I still don't want to leave points and figures lying around in my drawings with elevations that could be confused with real numbers. I have set my figure styles to draw fences and building walls flattened to zero, but that only affects the visual appearance, the figures still have the point elevations on them.
So when I shoot something that is not intended to have a valid elevation I use a 99 foot rod height. When I run the raw data trough StarNet I add the ".3r" inline command to data which has 99 foot rod heights which causes the points generated to have -99999 foot elevation assigned to them. I can leave those points with that elevation on them, which nobody could confuse with a reasonable number, or I can universally edit them to zero (or any other number) by any of several methods.
In this manner I get a drawing file that has the figures and points that should be in 3d on 3d ,and those that should be 2d only flattened. But it's a lot of work and I'd like to know if any of you have a better way.
I don't use civil 3d but all of my non dtm shots go automatically to zero through Carlson F2F and have no elevation attribute either. So whether shot reflectorless or not, fences, walls, poles hydrants etc. never have any elevation data unless I want it. I find it is easier to just keep them all clearly zero and nothing else.
Which part of your current process is slowing things down? Your current system seems like the way many are doing it already.
Totalsurv, post: 399538, member: 8202 wrote: Your current system seems like the way many are doing it already.
Best case, I'd like for the figures that have been flattened to actually be flattened, not just have the visual appearance of having been. Probably what i want is for C3d to work like Carlson does in this regard.
Mark Mayer, post: 399539, member: 424 wrote: Best case, I'd like for the figures that have been flattened to actually be flattened, not just have the visual appearance of having been. Probably what i want is for C3d to work like Carlson does in this regard.
It's surprising that Civil 3d does not have a way of doing this.
It looks like you can flatten a figure to any elevation in the figure's style.
Geoff Ashworth, post: 399561, member: 47 wrote: It looks like you can flatten a figure to any elevation in the figure's style.
Try it. That setting will make the figure appear as if flattened, but it will still have the point elevations on it, ie/assigned to each vertex. It doesn't actually flatten the figure.
I would adjust your F2F file and create a layer, or code for reflectorless shots, then remove that layer/point group from your DTM/Surface settings. A little work up front, but then you never have to adjust.
I put a - (dash) in front of any description that is to be a non elevation, then it is simple to change the elevation to zero on any point code that has a dash in front
Totalsurv, post: 399542, member: 8202 wrote: It's surprising that Civil 3d does not have a way of doing this.
It can be done using the FLATTEN command, but it is time consuming and FRUSTRATING!
Jim in AZ, post: 399576, member: 249 wrote: It can be done using the FLATTEN command, but it is time consuming and FRUSTRATING!
You can explode a figure and then FLATTEN it, but if you do you will lose any curves that were in the figure.
I have used "point groups" to separate 3d and 2d points in C3D, but that requires a little "pre-flight" separation work on the original collection file. Actually what you've described really isn't a bad method. As with anything, there is always a bogey that slips through. They are usually evident in the surface model...like a FH shot that was taken on the top nut...and the contours appear as though a 10 wheeler dumped a load on the corner.
I usually create a point group named topo and just include those points I want to use for the surface creation.
Jim in AZ, post: 399595, member: 249 wrote: those points I want to use for the surface creation
I have no problem with surface creation. My points are layerized in such a way that selecting points for the DTM is a simple matter.
What I'm looking for is a (better) way of having certain figures be drawn with no or zero elevation - not just appear so on the screen - but actually be on zero elevation.
paden cash, post: 399588, member: 20 wrote: .... like a FH shot that was taken on the top nut ...
As an aside, I don't use any hydrant shots in the DTM, top or bottom. In fact I don't use any utility shots in the DTM. Still, a lot of those elevations, such as on manhole rims, are valid elevations. I just don't use them in the DTM. I will use them to check the DTM.
I do not use building walls in the DTM. I usually shoot the building face reflectorless (close to, but not right at the corner, if possible) and later intersect the faces to create the corners. I'll get a breakline near the wall if appropriate.
I don't use fencelines in the DTM. I often shoot those reflectorless also. And I only shoot the angle points. Fences are not breaklines.
F2f controls the layering of all this. Building a DTM point group out of points with the appropriate codes is all built into my template.
Are you wanting the entities to stay as survey figures? If so, you can use Elevation Editor, but that only works with one figure at a time.
Or are you wanting 2D polylines? Eric Chappell has a lisp routine that might help. I believe that there is a routine in SincPac that does this as well.
I honestly never noticed that setting the figure style to flatten to 0 didn't actually achieve that. Thanks for enlightening me. I'm not sure that I would sweat it much myself, but it's good to know.
BlitzkriegBob, post: 399631, member: 9554 wrote: Are you wanting the entities to stay as survey figures? If so, you can use Elevation Editor, but that only works with one figure at a time..
That gets old fast. Looking for a better way. Figures are okay - I generally end up exporting the C3d drawing to AutoCAD for use by clients that don't have C3d anyway.
BlitzkriegBob, post: 399631, member: 9554 wrote: Or are you wanting 2D polylines? Eric Chappell has a lisp routine that might help. I believe that there is a routine in SincPac that does this as well.
I'm familiar with Sincpac and what it can do. I'd just rather not add that overhead. I'll check out the LISP you linked but I suspect that it is going to remove any curves from the figures.
Mark Mayer, post: 399632, member: 424 wrote: That gets old fast. Looking for a better way. Figures are okay - I generally end up exporting the C3d drawing to AutoCAD for use by clients that don't have C3d anyway.
Here's a dumb question. When you export the drawing, what do survey figures become? 3D or 2D polylines?
The way we handle this is explode the figures. Convert 3d polylines to 2d and then flatten. When surfacing, we use proximity break lines and don't convert to standard. We do this because the end users of our data request it like that, but I think it would serve the same purpose you are looking for.
BlitzkriegBob, post: 399637, member: 9554 wrote: When you export the drawing, what do survey figures become? 3D or 2D polylines?
3d polys.
doogle1973, post: 399638, member: 1552 wrote: The way we handle this is explode the figures. Convert 3d polylines to 2d and then flatten.
That's OK, except for 2 things. It's a lot of data handling. And it blows up any curves in the figure. Which would have to be manually redrawn. Looking for better.
