An InRoads user posted this question to Mark:
Mohamed: Hello, Mohamed with you. I need your help. I'm highway design engineer and I'm using now InRoads. I have some question. How can I delete point with range elevation, like I want to delete zero level or negative level from survey surface?
(Mark will always do his best to understand the question and post a relevant answer.)
Hello Mohamed,
I'll see if I can help you a little. My advice might be hard to follow if you are very unfamiliar with InRoads because it would take forever to explain something from the ground up. If you are brand new to InRoads, I highly recommend getting some of my InRoads books from my website and studying that content.
There are a couple things regarding deleting points within an elevational range.
1)There is a tool that you can use under the InRoads Main Menu > Surface > Edit Surface > Delete Feature Points. This tool allows you to select a "Range to Keep". And will delete all Random Points that are outside of this range. Keep in mind that this tool only works on the points that are 'Random" points, not points that are defined within Breaklines or other linear Point Types. This might not be directly obvious, but the Features that are listed in the list window are only Random Features, and you won't see any Breakline or other linear-type Features. You have to select the Features that you want to apply the tool to, so if you aren't sure which Features contain the 'zero' elevations then just select all of them. When you "Apply" the command the "Results" button will activate. Click on that button to see the results. The biggest thing to be aware of using this command is that the range that you enter into the command is the "Range to Keep".
2) The command above will handle the 'zero' elevations if they are Random points. If they are Breaklines, that's another story. There really isn't a tool like the Delete Feature Points command that works on Breaklines, but that's really because you have to make sure you really understand the implications of deleting 'zero' elevation points out of a Breakline. Think about this, you have a Feature that is a Breakline that defines an edge of pavement. That line is defined by points or 'vertices'. Each of those points has an elevation on it. The line itself is described from point to point to point to point to point and so on. Each point on the line is a vertex that defines the path. If you start taking out vertices along that line it could very well change the path entirely. I'm sure the programmers thought about this when they didn't include the deletion of breakline points using the Delete Feature Point command described above. What you CAN do is delete them using the Surface > Edit Surface > Edit Feature Point tool. This tool will definitely get the job done, but you have to know where they are. That's not that hard because generally you do know where they are if you have been building a surface model and found the triangles or contours going down to the 'zero' locations. If you know the locations, or general location, the Edit Feature Point tool has 'target' or 'locate' buttons next to the Feature and Point areas to help you find the exact Feature and the specific Point. Then you just click the Delete button on the right to remove that point. After deleting the point or points you have to click the Apply button to write those deletion edits to the DTM.
And actually, while you are in there, you might decide that instead of removing the points you choose to assign the correct elevation. You can do that by just entering the Elevation and clicking Apply.
Then go to the Surface > Features > Feature Properties command and activate the Feature Filter to show only Breaklines that have data containing 'zero' elevations. The Feature list window should now show only those Breakline Features.To verify this, select one of them and click the List Point button on the right and check to see that it has elevations at 'zero'. This is just a check to make sure that your Feature Filter is working. (Remember ... always check your work along the way.) You may want to check several Features to make double or triple sure that it's showing the correct results. Now, close that List Points window and right-click in that list window and Select All. At this point you are selecting all of the Breaklines that contain a 'zero' elevation. Once those are selected, change the Point Type from Breakline to Random and Apply. This is a temporary step to remove the 'zero' elevations. You will be changing them back to Breaklines after you remove the 'zero' elevations. While those Features are selected add a Description or Parent description in there so you can easily locate these Features later. This is because you need to change them back to Breaklines once the 'zero' elevations are removed, and your Feature Filter won't work anymore once the 'zero' elevations are removed. Get it?
4) A technique to find out which Features in the surface contain zero elevations is to build a Feature Filter. This is done under Surface > Feature > Feature Selection Filter. Start with a Rule that Excludes All Features and then add a Rule (or more) that defines the elevation ranges that you want to find. If you are trying to find that range then you need to "Include" those features, if you are trying to find everything else then you would 'Exclude' those features. Basically the "Include / Exclude" become part of the Rule that sorts the data. The Attribute is "Elevation", and the "Value" is the elevational range like -1 to 1. (The InRoads Help shows the various formats that the elevational range can be entered.)
Great Instructor. Thoroughly explained everything and so clearly. Used good examples when explaining concepts. Enjoyed it, learned a lot. 
