FVCOM Bathymetry

This example demonstrates how to render a warped unstructured triangular mesh.

📋 Summary

Creates a mesh from 1-D latitude and longitude unstructured points and connectivity, warped to show the vertical profile.

It uses an unstructured grid Finite Volume Community Ocean Model (FVCOM) mesh of sea floor depth below geoid data.

The resulting mesh contains triangular cells. The connectivity is required to construct the cells from the unstructured points.

Note that, the data is on the mesh faces/cells, but also on the nodes/points.

A pyvista “warp” operation is used to extrude the mesh by the point depth values, to reveal the bathymetry of the Plymouth Sound and Tamar River in Cornwall, UK.

The warp uses compute_normals() and warp_by_scalar(). See Computing Surface Normals for further details.

Tags: Unstructured Warp

---

Static Scene

Interactive Scene

from __future__ import annotations

import geovista as gv
from geovista.pantry.data import fvcom_tamar
import geovista.theme


def main() -> None:
    """Plot a warped FVCOM unstructured mesh.

    Notes
    -----
    .. versionadded:: 0.1.0

    """
    # Load the sample data.
    sample = fvcom_tamar()

    # Create the mesh from the sample data.
    mesh = gv.Transform.from_unstructured(
        sample.lons,
        sample.lats,
        connectivity=sample.connectivity,
        data=sample.face,
        name="face",
    )

    # Warp the mesh nodes by the bathymetry.
    mesh.point_data["node"] = sample.node
    mesh.compute_normals(cell_normals=False, point_normals=True, inplace=True)
    mesh.warp_by_scalar(scalars="node", inplace=True, factor=2e-5)

    # Plot the unstructured mesh.
    plotter = gv.GeoPlotter()
    sargs = {"title": f"{sample.name} / {sample.units}", "shadow": True}
    plotter.add_mesh(mesh, cmap="deep", scalars="face", scalar_bar_args=sargs)
    plotter.add_axes()
    plotter.add_text(
        "PML FVCOM Tamar",
        position="upper_left",
        font_size=10,
        shadow=True,
    )
    plotter.camera.zoom(1.2)
    plotter.show()


if __name__ == "__main__":
    main()