Data¶

Before applying any effect to your mesh, you will need to load node data.

The Data and Component widgets represents the node data for an unstructured mesh.

A Data widget is made of a name property and a list of components. As an example, a temperature Data (1D) would be made of a list of one Component, a displacement Data (3D) would be made of a list of three Components.
A Component widget is made of a name property and an array property.

Those data are loaded automatically when loading a mesh from a vtk file. If you manually create a PolyMesh or a TetraMesh, you will need to manually create the node data.

Example¶

When loading a vtk file, the Data and Component widgets are created automatically from the node data in the file:

from ipygany import TetraMesh

mesh = TetraMesh.from_vtk('assets/piston.vtu')

for data in mesh.data:
    print(data.name, ':', [component.name for component in data.components])

RESU____DEPL : ['DX', 'DY', 'DZ']
RESU____SIGM_NOEU : ['SIXX', 'SIYY', 'SIZZ', 'SIXY', 'SIXZ', 'SIYZ']

When loading a mesh from memory, you will need to manually pass your node data:

import numpy as np
from ipygany import Scene, PolyMesh, Component, IsoColor


# Create triangle indices
Nr = 100
Nc = 100

triangle_indices = np.empty((Nr - 1, Nc - 1, 2, 3), dtype=int)

r = np.arange(Nr * Nc).reshape(Nr, Nc)

triangle_indices[:, :, 0, 0] = r[:-1, :-1]
triangle_indices[:, :, 1, 0] = r[:-1, 1:]
triangle_indices[:, :, 0, 1] = r[:-1, 1:]

triangle_indices[:, :, 1, 1] = r[1:, 1:]
triangle_indices[:, :, :, 2] = r[1:, :-1, None]

triangle_indices.shape = (-1, 3)

# Create vertices
x = np.arange(-5, 5, 0.1)
y = np.arange(-5, 5, 0.1)

xx, yy = np.meshgrid(x, y, sparse=True)

z = np.sin(xx**2 + yy**2) / (xx**2 + yy**2)

vertices = np.empty((100, 100, 3))
vertices[:, :, 0] = xx
vertices[:, :, 1] = yy
vertices[:, :, 2] = z
vertices = vertices.reshape(10000, 3)

height_component = Component(name='value', array=z)

mesh = PolyMesh(
    vertices=vertices,
    triangle_indices=triangle_indices,
    data={'height': [height_component]}
)

# Colorize by curvature
colored_mesh = IsoColor(mesh, input=('height', 'value'), min=np.min(z), max=np.max(z))

scene = Scene([colored_mesh])
scene