如何在 pyvista 中填充两个网格之间的距离 cells/mesh？

Question

所以我看了这个 sample 并且我想创建一个 mesh/surface 网格来填充那个距离。如何在 PyVista 中做这样的事情？

我尝试过的，似乎无法与美丽的Andras Deak搭桥：

import pyvista as pv
import numpy as np
import matplotlib.pyplot as plt
from scipy.spatial import KDTree
import PVGeo
from PVGeo import interface
from PVGeo.filters import BuildSurfaceFromPoints

b = pv.read('./top.vtk') # PolyData
t = pv.read('./bottom.vtk') # PolyData

dim = (int(b.bounds[1]-b.bounds[0]), int(b.bounds[3]-b.bounds[2]), 1)
z_range =  np.arange(b.bounds[4], b.bounds[5] )
bottom = BuildSurfaceFromPoints().apply(b)
top = BuildSurfaceFromPoints().apply(t)

grid_2d = top.points.reshape(dim[:-1] + (3,), order='F')[..., :-1]

不幸的是，与 grid_2d 和

在线失败

ValueError: cannot reshape array of size 1942464 into shape (30150,26750,3)

Answer 1

我不知道是否有内置方法可以在两个表面之间进行插值，但仅使用 numpy 并不难。

下面是一个使用 Perlin noise 在同一网格上以两个不同高度生成两张数据的示例。答案的实际代码在后面。

import numpy as np
import pyvista as pv

# generate two sheets of input data
noise = pv.perlin_noise(2, (0.2, 0.2, 0.2), (0, 0, 0))
bounds_2d = (-10, 10, -10, 10)
dim = (40, 50, 1)
bottom, top = [
    pv.sample_function(noise, dim=dim, bounds=bounds_2d + (z, z)).warp_by_scalar()
    for z in [-5, 5]
]

# actual answer starts here
# the top and bottom sheets are named `top` and `bottom`
# and they share the same 2d grid

# rebuild grid points
grid_2d = top.points.reshape(dim[:-1] + (3,), order='F')[..., :-1]
values_x = grid_2d[:, 0, 0]
values_y = grid_2d[0, :, 1]

# generate full grid with equidistant interpolation in each (x, y)
nz = 10
scale = np.linspace(0, 1, nz)
scale_z = scale[:, None] * [0, 0, 1]  # shape (nz, 3)
scale_z_inv = (1 - scale[:, None]) * [0, 0, 1]  # shape (nz, 3)
z_bottom = bottom.points.reshape(dim[:-1] + (3,), order='F')[..., -1]  # shape (nx, ny)
z_top = top.points.reshape(dim[:-1] + (3,), order='F')[..., -1]  # shape (nx, ny)
interpolated_z = scale * z_bottom[..., None] + (1 - scale) * z_top[..., None]  # shape (nx, ny, nz)

grid_2d_in_3d = np.pad(grid_2d, [(0, 0), (0, 0), (0, 1)])  # shape (nx, ny, 3)
final_grid = grid_2d_in_3d[..., None, :] + interpolated_z[..., None] * [0, 0, 1]  # shape (nx, ny, nz, 3)
mesh = pv.StructuredGrid(*final_grid.transpose())

# plot the two sheets and the interpolated grid
pv.set_plot_theme('document')
plotter = pv.Plotter()
plotter.add_mesh(bottom, show_scalar_bar=False)
plotter.add_mesh(top, show_scalar_bar=False)
plotter.add_mesh(mesh, style='wireframe')
plotter.show()

如何在 pyvista 中填充两个网格之间的距离 cells/mesh？

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