Importing local files

[jc-barreto]

Hi,

I'm new to GemPy and I'm trying to modify this example: GemPy Tutorial by simply modifying the G_x, G_y, and G_z coordinates because we often do not have this information beforehand. I am working with alluvium deposits solely for common foundation design (not in mining or oil and gas), and we only have data from boreholes. I would appreciate it if someone could help me understand and explore this further. I've watched several videos, but they often assume data from GitHub and include orientation information.

So:
How do I use local data? Is there are any examples of reading local data from boreholes? I attempted to export the data from the example as follows:

surface_df = geo_model.surface_points_copy.df
surface_df.to_csv('surface.csv')
orientation_df = geo_model.orientations_copy.df
orientation_df.to_csv('orientation.csv')

Then, I manually modified G_x, G_y, and G_z by setting them to 0 and created a new model using this data like this:

geo_model: gp.data.GeoModel = gp.create_geomodel(
    project_name='Tutorial_ch1_1_Basics',
    extent=[0, 2000, 0, 2000, 0, 750],
    refinement=6,  # Here, we define the number of octree levels. If octree levels are defined, the resolution is ignored.
    importer_helper=gp.data.ImporterHelper(
        path_to_orientations="C:/Users/orientation.csv",
        path_to_surface_points="C:/Users/surface.csv",
    )
)

However, this results in an error because the exported data does not contain a "formation" column, which is required. I noticed that renaming the "id" column to "formation" allows the data to be read but triggers another error soon after. I'm confused as to why the code reads a file, modifies the column names, and then exports another file. Is that what's happening?

My goal is to create a simple model without fault and orientation data—only interpolating the borehole data to create a 3D model—and then export it to a format that can be read in Revit, as I mentioned in this question, could someone give me some insights in how to proceed?

Thank you in advance

[javoha]

Hi @jc-barreto,

thanks for your question. I hope I can clarify some things. The code you show in your example exports the surface points and orientation dataframes from an existing model. The problem here is that gempy processes input data and creates things like the nugget and the id. The actual format that gempy requires is a littel different:
For surface points (e.g the bottom of a strucutural element - usually a rock unit) we need the columns X Y Z and a column named formation which contains the name of the element. An example can be found here: LINK.
For orientations we again need columns X Y Z, formation and also data indicating the direction. Thsi can either be given by azimuth dip polarity (linke in this example) or by the components of the normal (pole) vector using G_x G_y G_z.

This was the part purely on format. Now to your orientation issue: gempy uses a Universal-Cokriging approach (see literature on fromt page if interested) which always requires orientations. There are a couple of workarounds however. Depending on your geometry and complexity of your model and the density of available input data, yyou can either
a) Set a couple of maunual orientations, most simple would be just upward facing.
b) Try to interpolate orientations from surface points

Regarding output: Depends on which part of the model you want to export to Revit. The created surfac meshes are stored ing empy. You should be able to export them using maybe pyvista to a format that revit can reead but maybe we need more information on what specifically you want to export.

[jc-barreto]

Thank you, @javoha, for your response. I understand that I'm attempting to use GemPy in an environment it might not have been originally designed for, yet I am confident it is achievable! GemPy primarily provides surfaces, while our goal is to generate solid objects for producing GeoBIM models. Currently, the surfaces exported as DXF using the ezdxf library, as discussed in this post by @NilsChudalla, are interpreted in AutoCAD merely as lines. I need them to be triangle meshes to perform extrusions and connect each bottom surface with the top surface effectively.

Is there a method to export these as triangle meshes and/or perform the extrusion directly in Python so that I can export a solid model in formats like .obj, .stl, or .fbx? Although I can execute these tasks manually with blender-rhino-civil 3D/Revit like here, they are quite repetitive, and doing them by hand would be excessively time-consuming, especially given the large number of geological models we must develop.

I appreciate your time and attention.

[javoha]

Hi again,
not sure if I can provide a sufficient answer here but let me try. So apart from the surface meshes you are referencing gempy also does store the lithology unit by int value for each point in the regular grid. You can "explode" this information to create a block model ( I posted an image of something like this in #953 a while ago, just to give you an idea what this can look like).

Not sure if it is possible to convert the surface meshes created by gempy to triangular meshes with some python library (e.g pyvista?)

Creating volumetric (for example tetrahedral meshes) meshes can be very tricky, especially if you need to meet certain requirements (e.g watertight meshes) or something like that.

Does that help?

[NilsChudalla]

Hi @jc-barreto,

I created the Blender workflow in the GEMGIS tutorial that you mentioned. If the solution @javoha mentioned in #953 is not sufficient, I feel like this could turn into a quite lengthy discussion, given that you could get a PhD for solving automatic meshing :D

I would suggest, that we try to keep the topics of our dicussions in seperate threads. Let us focus on the input stuff in this thread and the BIM stuff in #990 :)