Some questions about the Distance Function Object

I am using the Distance Function to create a block model from my fault system. 
Please refer one of my previous question:
1) If I have multiple objects considered in Distance Function. Am I correct that the number I see in the end is the distance to the closest object?

2) Is is correct that Distance Function can not create a numeric model that consider the topography in the model? I tried to create the block model based on the Distance Function but it was providing a block model including the blocks above the ground.

Thanks for the answering!


  • [Deleted User]
    [Deleted User] Posts: 6 admin
    Hello @YuTingYu is this still an issue for you?
  • KathrynGall
    KathrynGall Posts: 32 mod
    Hi @YuTingYu , 

    Yes, the distance buffer works on distance to the closest object when you have multiple objects. 

    The Distance Buffer works in 3D, so it creates a distance buffer around the topography in full (above, below and sides). 

    If you want to remove the distance above the topography, the best option may be to use a calculation on the block model. Calculations can be accessed if you have the Edge module added to your Leapfrog license. 

    You will need a category field on the block model to differentiate the above and below topography blocks. This can be done two ways. 

    In Leapfrog Geo 2022.1, the best workflow is to use a Geology Model. 

    Create a New geological model that has the Topography activated.
    Set Base Lithology to None, 
    Add a new Lithology with Below Topography. 
    Double-click Surface Chronology and set a background to the new Lithology added. 
    The output volume should just be a closed volume of the ground below the topography. 
    This GM can be evaluated onto the Block Model. 

    In the next release of Leapfrog 2023.1 due out very soon, open surfaces will be allowed in Group Meshes.

    Right-click Combined Models > Grouped Meshes
    Select the + symbol to add your Topography Surface
    Set the Category Above your Topography as Air
    Check the box for Background and set the Category as Background or the desired Unit. 
    Evaluate this Grouped Mesh onto the block model. 
    Use the Block Model display drop down to display the block model by the Grouped Mesh. 

    Once you have the attribute, you can create a new numeric calculation that allows for replacing the numeric values above topography with a null or zero value. See the images below. 

    On the Calcultions page, Select New Item, New Numeric Calculation. 
    Add an If statement. 
    When my GM or Grouped Mesh is equal to Air than the numeric value is 0. 
    For everyone else below Topography, the results of the distance buffer still stand.