Trimble Business Center

 View Only
Expand all | Collapse all

Why can I not calculate a stockpile/depression volume from a surface with a trimmed boundary?

  • 1.  Why can I not calculate a stockpile/depression volume from a surface with a trimmed boundary?

    Posted 01-11-2019 06:06

    Disclaimer: I believe I have brought up this topic before but I could not find it on the community page so I think it was on a different forum. Sorry if I posted this already in this forum.

     

     

    One of the issues that I continually run into is that you cannot run a stockpile/depression calculation on a surface with a trimmed boundary. 

     

    This morning I was trying to calculate stockpile volumes based off a a topoed surface I created in the field yesterday.

     

    I have also run into this issue when trying to obtain stockpile/depression volumes on takeoff surfaces (where there is usually a trimmed boundary applied).

     

    The quickest fix is to remove the trimmed boundary but this requires manipulating good data or finished work. You could also create a surface based on the information you need but this seems like a redundant step because the data is already there, the user just wants to run a calculation. 

     

    We need the ability to run a stockpile/depression on a surface that has a trimmed boundary applied to it. This is a very common calculation that I have to constantly work around. This would be a very useful.

     

    Thank you.

     



  • 2.  Re: Why can I not calculate a stockpile/depression volume from a surface with a trimmed boundary?

    Posted 01-11-2019 08:38

    Pat

    When you have a Design Surface Model, unless it has Holes and Islands in it, you don't need to add a surface Edge Breakline to it as a Boundary - just add it as a surface member - it serves the same purposes as a boundary in that instance - i.e. it stops erroneous triangles forming along its edge on the outside once you have the edges cleaned up as you need them. Then your Pond example will work no problem.  This may help you with this type of example. If you had e.g. a large wetland area in the middle of the site and you need to add boundaries to create the Hole then of course you are hosed (if things stay as they are).

     

    When you apply a Boundary to a Surface Model, it is so that you can create Islands (like your Stockpiles), or Holes in the model (areas where you don't want a surface or contours etc. The Surface Boundary object(s) nest so that the first boundary acts as an "Island Creator" and any boundaries applied inside the first boundary become "Hole Creators". If you draw a boundary inside a Hole then it becomes an island again and so on. Each alternate boundary being the alternate Island - Hole - Island - Hole etc. We call this Region Logic.

     

    When you apply a Boundary to a surface to e.g. create a hole, it effectively Nulls out Triangles inside the Hole boundary. When you do it as an Island, it nulls out the Triangles outside the boundary. The triangles are there they are just hidden. You can get the same effect by making the boundaries Sharp and Texture Boundaries and then applying a Null (No) Texture to the triangles outside or inside of the boundary. However that has the same exact effect on this calculation - so this did not work for me either. 

     

    I created some examples this morning to test this out, and confirm that your finding is correct. I have started the discussion with development today to find out why adding the Surface Boundaries creates this issue with these calculations. The initial response was that without that check, we had complaints early on that the results given were erroneous when in certain situations Surface Boundaries were applied, so they limited the calculation for that reason to stop the erroneous calculations from happening. They also told me some other stuff which after more testing appears to be incorrect (I was surprised at what I was told so I double checked and what I was told was incorrect (thankfully).

     

    I guess the reason why the Stockpile / depression volume won't work when there are surface boundaries applied is because of something to do with the hidden triangles - I will ask development today why this is the case and get back to you.

     

    To be honest whenever I have done Stockpiles, I typically survey the Base in between the Piles as well as the piles themselves, and then I make two surfaces - one for the base and one for the Top and then do Surface to Surface with multiple Boundaries to compute each pile, rather than run the Stockpile calculation. Even if I did it using the Stockpile calculation, I would just have one surface and do it to the boundary of the Pile (SCS900 Volume Boundary) and would not necessarily worry about the connections between the piles - I guess those can be cleaned up for presentation after the volume is computed - but I do get your point here and I will find out why that restricts you on this. In this case I would make 3 surfaces - one for each pile rather than one surface with surface boundaries applied - I guess it all depends on how you hold your data over time for the stockyards you are surveying.

     

    While I don't see your issue as a show stopper defect (as there are easy work arounds), I do think this could be better managed and I am waiting for development feedback on this to understand the real reason why we put a limit on this with Boundaries.

     

    Alan



  • 3.  Re: Why can I not calculate a stockpile/depression volume from a surface with a trimmed boundary?

    Posted 01-11-2019 18:49

    Patrick: First, Alan's reply is really good and detailed. I learned some things about boundaries.

     

    Anyway, I followed along like he did and created some adjacent stockpiles from points data that was sent in from the field. I tried every combination of ways to do this and see what I could come up with.

     

    The option that worked best was to create the 'baselines' around the piles but not add them to the surface as boundaries and then run the stockpile calculation using each baseline as a "boundary". After running the three piles calculations I then just added the baselines as boundaries to clean up the view.

     

    The same process worked when I simulated a depression like your pond example (by lowering all the points from the stockpile so they were 'below' ground level).

     

    Like Alan, I tend to run stockpiles in the field with SCS900 Volume Boundaries. This avoids the problem in TBC and saves me creating baselines by 'hand' in the office. Alternatively, in the field, I create breaklines around the piles if they are complex shapes or running together or are stacked up against each other. Then in TBC just "close" the ends of these lines to create "boundaries".

     

    I would bet that the boundary/stockpile issue has to do with the triangles created between the piles. Boundaries do not actually delete the TIN between the piles, just hides them. I did try a few calculations of all the piles with no baselines around them and the volumes were completely whacky...that's a technical term meaning fubar  

     

    It'll be interesting to hear the follow up from the development team.

     

    Marshall



  • 4.  Re: Why can I not calculate a stockpile/depression volume from a surface with a trimmed boundary?

    Posted 01-12-2019 05:32

    I agree Alan, definitely not a show stopper but for the novice or beginner TBCer it adds extra steps. And for myself when I am trying to spit out quantities in the front seat of my car during peak season. That is usually when I cringe and say there must be a better way. One or my goals during this winter is to go through and tackle some of the items that I feel slow me down and see if it is a personal workflow issue or maybe there is some tweaks that can be made in TBC to smooth out the process. This forum and the Trimble Retrieve Library have both been great assets for addressing these workflow issues and bugs. 

     

    I do the same thing in SCS900/Siteworks with the volume boundary and breaklines. It is a time saver when you bring that data back into TBC and saves yourself from playing connect the dots. Siteworks does a very good job of modeling these surfaces in a 3D view so the user can verify that the topoed data accurately represents what the stockpile in the field looks like. 

     

    I agree that the triangles between piles are probably the source of the issue. What if the function required a boundary selected within the trim surface for the stockpile/depression? If there is no boundary selected that meets the criteria of being within the trimmed surface then it gives you an error message. This would allow the user to run the stockpile/depression without getting weird results and the program would not have to try and compute something that it cannot. 

     

    I think this would be useful because typically I am trying to calculate a volume of a specific area/areas within the surface not the volume of the whole surface. 

     

     



  • 5.  Re: Why can I not calculate a stockpile/depression volume from a surface with a trimmed boundary?

    Posted 01-22-2019 16:23

    This has just been fixed and will be in the next release Pat

     

    Alan



  • 6.  Re: Why can I not calculate a stockpile/depression volume from a surface with a trimmed boundary?

    Posted 01-23-2019 04:00

    Thank you for looking into this Alan.