# Plot a Gyroid Surface
# =====================

# Contour an implicit gyroid field stored on `pyvista.ImageData` into a
# periodic surface with `pyvista.DataSetFilters.contour()`.
import numpy as np
import pyvista as pv

# Sample the implicit field
# -------------------------

# The gyroid is the zero level set of
# `sin(x)cos(y) + sin(y)cos(z) + sin(z)cos(x)`.
n = 50
x, y, z = np.mgrid[
    -np.pi : np.pi : complex(0, n),
    -np.pi : np.pi : complex(0, n),
    -np.pi : np.pi : complex(0, n),
]
values = np.sin(x) * np.cos(y) + np.sin(y) * np.cos(z) + np.sin(z) * np.cos(x)

grid = pv.ImageData(dimensions=values.shape)
grid.origin = (-np.pi, -np.pi, -np.pi)
grid.spacing = (2 * np.pi / (n - 1),) * 3
grid['gyroid'] = values.ravel(order='F')
grid

# Extract the zero isosurface
# ---------------------------

# The contour weaves through the periodic sample volume.
surface = grid.contour([0.0], scalars='gyroid')

pl = pv.Plotter()
pl.add_mesh(surface, color='royalblue', smooth_shading=True)
pl.show()

# ----------------------------------------------------------------------
# Generated by sphinx-examples-as-code https://github.com/pyvista/sphinx-examples-as-code