Export volumes and cube faces as VTK unstructured grids

LoopStructural/export/exporters.py

@@ -0,0 +1,175 @@
+"""
+Routines to export geological model data to file in a variety of formats
+"""
+import logging
+from pyevtk.hl import unstructuredGridToVTK, pointsToVTK
+from pyevtk.vtk import VtkTriangle
+import numpy as np
+
+from LoopStructural.utils.helper import create_box
+from LoopStructural.export.file_formats import FileFormat
+
+
+logger = logging.getLogger(__name__)
+
+
+def write_cubeface(model, file_name, data_label, nsteps, file_format):
+    """
+    Writes out the model as a cuboid with six rectangular surfaces
+
+    Parameters
+    ----------
+    model : GeologicalModel object
+        Geological model to export
+    file_name : string
+        Name of file that model is exported to, including path, but without the file extension
+    data_label : string
+        A data label to insert into export file
+    nsteps : np.array([num-x-steps, num-y-steps, num-z-steps])
+        3d array dimensions
+    file_format: export.fileformats.FileFormat object
+        Desired format of exported file
+
+    Returns
+    -------
+    True if successful
+
+    """
+    if file_format == FileFormat.VTK:
+        return _write_cubeface_evtk(model, file_name, data_label, nsteps)
+
+    logger.warning("Cannot export to file - format {} not supported yet".format(str(file_format)))
+    return False
+
+
+def write_vol(model, file_name, data_label, nsteps, file_format):
+    """
+    Writes out the model as a 3d volume grid
+
+    Parameters
+    ----------
+    model : GeologicalModel object
+        Geological model to export
+    file_name : string
+        Name of file that model is exported to, including path, but without the file extension
+    data_label : string
+        A data label to insert into export file
+    nsteps : np.array([num-x-steps, num-y-steps, num-z-steps])
+        3d array dimensions
+    file_format: export.fileformats.FileFormat object
+        Desired format of exported file
+
+    Returns
+    -------
+    True if successful
+
+    """
+    if file_format == FileFormat.VTK:
+        return _write_vol_evtk(model, file_name, data_label, nsteps)
+
+    logger.warning("Cannot export to file - format {} not supported yet".format(str(file_format)))
+    return False
+
+
+def _write_cubeface_evtk(model, file_name, data_label, nsteps, real_coords=True):
+    """
+    Writes out the model as a cuboid with six rectangular surfaces
+
+    Parameters
+    ----------
+    model : GeologicalModel object
+        Geological model to export
+    file_name : string
+        Name of file that model is exported to, including path, but without the file extension
+    data_label : string
+        A data label to insert into export file
+    nsteps : np.array([num-x-steps, num-y-steps, num-z-steps])
+        3d array dimensions
+
+    Returns
+    -------
+    True if successful
+
+    """
+    # Evaluate model at points
+    points, tri = create_box(model.bounding_box, nsteps)
+    val = model.evaluate_model(points, scale=False)
+    if real_coords:
+        model.rescale(points)
+
+    # Define vertices
+    x = np.zeros(points.shape[0])
+    y = np.zeros(points.shape[0])
+    z = np.zeros(points.shape[0])
+    for i in range(points.shape[0]):
+        x[i], y[i], z[i] = points[i][0], points[i][1], points[i][2]
+
+    # Define connectivity or vertices that belongs to each element
+    conn = np.zeros(tri.shape[0] * 3)
+    for i in range(tri.shape[0]):
+        conn[i*3], conn[i*3+1], conn[i*3+2] = tri[i][0], tri[i][1], tri[i][2]
+
+    # Define offset of last vertex of each element
+    offset = np.zeros(tri.shape[0])
+    for i in range(tri.shape[0]):
+        offset[i] = (i+1)*3
+
+    # Define cell types
+    ctype = np.full(tri.shape[0], VtkTriangle.tid)
+
+    try:
+        unstructuredGridToVTK(file_name, x, y, z, connectivity = conn, offsets = offset, cell_types = ctype, cellData = None, pointData = {data_label: val})
+    except Exception as e:
+        logger.warning("Cannot export cuboid surface to file {}: {}".format(file_name, str(e)))
+        return False
+    return True 
+
+
+def _write_vol_evtk(model, file_name, data_label, nsteps, real_coords=True):
+    """
+    Writes out the model as a 3d volume grid
+
+    Parameters
+    ----------
+    model : GeologicalModel object
+        Geological model to export
+    file_name : string
+        Name of file that model is exported to, including path, but without the file extension
+    data_label : string
+        A data label to insert into export file
+    nsteps : np.array([num-x-steps, num-y-steps, num-z-steps])
+        3d array dimensions
+
+    Returns
+    -------
+    True if successful
+
+    """
+    # Define grid spacing
+    loop_X = np.linspace(model.bounding_box[0, 0], model.bounding_box[1, 0], nsteps[0])
+    loop_Y = np.linspace(model.bounding_box[0, 1], model.bounding_box[1, 1], nsteps[1])
+    loop_Z = np.linspace(model.bounding_box[0, 2], model.bounding_box[1, 2], nsteps[2])
+
+    # Generate model values in 3d grid
+    xx, yy, zz = np.meshgrid(loop_X, loop_Y, loop_Z, indexing='ij')
+    xyz = np.array([xx.flatten(), yy.flatten(), zz.flatten()]).T
+    vals = model.evaluate_model(xyz, scale=False)
+    if real_coords:
+        model.rescale(xyz)
+
+    # Define vertices
+    x = np.zeros(xyz.shape[0])
+    y = np.zeros(xyz.shape[0])
+    z = np.zeros(xyz.shape[0])
+    for i in range(xyz.shape[0]):
+        x[i], y[i], z[i] = xyz[i][0], xyz[i][1], xyz[i][2]
+
+    # Write to grid
+    try:
+        pointsToVTK(file_name, x, y, z, data= { data_label: vals})
+    except Exception as e:
+        logger.warning("Cannot export volume to file {}: {}".format(file_name, str(e)))
+        return False
+    return True 
+
+

LoopStructural/export/file_formats.py

@@ -0,0 +1,12 @@
+"""
+Exported file formats
+"""
+from enum import Enum
+
+class FileFormat(Enum):
+    """ Enumeration of file export formats 
+    """
+    OBJ = 1
+    VTK = 2
+    GZ = 3 # Not supported yet
+    GLTF = 4 # Not supported yet

requirements.txt

@@ -6,5 +6,6 @@ numpy
 matplotlib
 setuptools
 pandas
+pyevtk