Convert Maptek Vulcan Triangulation to Grid: Model_Triangle Surface_Grid Mesh | Mining University

Convert Maptek Vulcan Triangulation to Grid: Model_Triangle Surface_Grid Mesh


In Maptek Vulcan, triangulations and grids are used interchangeably for many tools. They are both used to represent 3D surfaces but converting from one to the other is often a confusing task. Due to the number of menu options that do almost the same thing, it is hard to find the right tool to convert surfaces efficiently. I know that I forget which menu option to use almost every time. This post shows the steps to convert a triangulation to a grid using the menu option: Model > Triangle Surface > Grid Mesh.

grid topography

To convert a surface triangulation to a grid select the tool Menu > Triangle Surface > Grid Mesh. Fill out the ‘Grid Parameters’ panel, keeping the following in mind.
  1. X Mesh Size and Y Mesh Size refer to how big the cells in the resulting grid are. Smaller cell size will give more resolution but eat up more memory. Unless your topo is truly gigantic start with the default size of 25.0 for each mesh.
  2. The 'Use Default Window' checkbox will use the default extents of the primary window as the grid extents. Leave this checkbox unchecked. I will show you a trick a little later in this post to set the grid lines at regular intervals (100.000 instead of 100.051 for example). The default window often has an origin that is not a whole number.
  3. Grid Model Name – give your grid a unique name. To this name will be added the project prefix and the extension .sfg (surface grid).
  4. Display X Mesh Lines and Display Y Mesh Lines. Make sure that these boxes are checked. If these boxes are left unchecked, your grid won’t display in the primary window after creation.


Grid parameters panel

Once you click ‘OK’ in the Grid Parameters panel, Vulcan will prompt you to ‘Indicate model origin point.’ Make sure that you are in plan view at this point. I like to specify a point that is farther east and south than the triangulation I am converting (0,0 for example). To do this click on the ‘Key in point data…’ icon in the ‘Digitise’ toolbar at the bottom of your screen. It looks like this:


 Type in your X and Y coordinates and then click the ‘Create Point’ button. Next, you will be prompted to ‘Indicate model extent.’ Click a point farther west and north than your triangulation. This second point is not as critical as the origin point. Grid lines will be counted from the origin point but the extents point is just signaling the end of the grid data.

That’s it. Your grid will now be saved in the working directory with all the rest of your files. You can find this grid in the Vulcan Explorer under the 'Grids' virtual folder.

8 comments:

  1. Hi

    How to create surface using top and bottom of a geological unit from drill hole database.

    hari

    ReplyDelete
  2. Hari,
    Thanks for taking the time to read my work.
    There are several ways to create a triangulation from drill hole data. One way to do it is to use the Vulcan menu option Geology > Drilling > Model.
    This option will allow you to use the drillhole database directly without compositing points. This will create either a surface roof or floor surface and works best with a tabular deposit.
    Let me know how this works for you.
    Thanks,
    Tony

    ReplyDelete
  3. Hi Anthony,

    What is the real function of grid in Vulcan? I don't see people use it frequently mostly surveyor. If you can create the triangulation then what's the purpose of having a grid of the triangulation?

    Cheers,
    Daniel

    ReplyDelete
    Replies
    1. Daniel,
      Good question. This article came to be as a result of my need to export a triangulation to a consultant. I usually work with triangulations and export them so frequently that I have to re-learn how to do it every time. I hope this article will help other people like me.
      As for the differences between triangulations and grids. Grids have regularly spaced nodes and often have smaller file sizes than triangulations. There are also more ways to estimate each node value with grids than there are with triangulations. All triangulations have nodes at the exact data points with little or no interpolation between points.
      Grids are often used in stratigraphic deposits like coal or phosphate while triangulations are popular for hard rock or vein type deposits.
      Hope this helps,
      Tony

      Delete
  4. Hi Anthony,
    Thanks for having this page. I'm starting to learn Vulcan and it has helped me a lot!

    Have you done a tutorial on creating a ground surface using a DEM? I'm trying to do that now and would like to also drape aerial imagery onto it if possible. Is there a better way for me to create this surface (with imagery).

    Thanks!

    Len

    ReplyDelete
  5. Hi Anthony, thanks for the helpful tips.

    I am new to Vulcan so seemingly simple tasks have been quite challenging so far... Therefore I have a question about triangulating two separate grid meshs.

    I have a grid representing the top of a coal bed and another which represents the bottom of the coal bed. I would like to triangulate the two creating a solid coal seam of which I can gather volumes, tonnages etc.

    Is there a way I can create a solid by joining these two grid meshs?

    Any help would be very much appreciated :)

    Blake

    ReplyDelete
  6. Hi Anthony, thanks for the helpful tips.

    I am new to Vulcan so seemingly simple tasks have been quite challenging so far... Therefore I have a question about triangulating two separate grid meshs.

    I have a grid representing the top of a coal bed and another which represents the bottom of the coal bed. I would like to triangulate the two creating a solid coal seam of which I can gather volumes, tonnages etc.

    Is there a way I can create a solid by joining these two grid meshs?

    Any help would be very much appreciated :)

    Blake

    ReplyDelete
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    ReplyDelete