在3D图中显示真彩色2D RGB纹理? [英] Displaying true-colour 2D RGB textures in a 3D plot?

问题描述

我正在尝试制作一个3D图，该图由通过RGB堆栈的一系列2D平面组成，如下所示:

I'm trying to make a 3D plot that consists of a series of 2D planes through an RGB stack, like this:

我知道可以使用mpl_toolkits.mplot3d通过将x，y，z坐标以及每个像素的RGB(A)颜色传递到plot_surface来实现:

I know that it's possible to do this using mpl_toolkits.mplot3d by passing the x, y, z coordinates and the RGB(A) colours of each pixel to plot_surface:

import numpy as np
from matplotlib import pyplot as pp
from mpl_toolkits.mplot3d.axes3d import Axes3D

def plot_stack_slices(rgbstack, scale=(1., 1., 1.), z_interval=10.):

    fig, ax = pp.subplots(1,1,subplot_kw={'projection':'3d'})
    ax.invert_zaxis()
    ax.hold(True)

    sx, sy, sz = scale
    nz, ny, nx, nc = rgbstack.shape

    stack_xyz = np.mgrid[:nx*sx:nx*1j, :ny*sy:ny*1j, :nz*sz:nz*1j]

    slices = rgbstack[::-z_interval]
    slice_xyz = np.rollaxis(stack_xyz, 3, 0)[::-z_interval]

    surflist = []

    for (img,xyz) in zip(slices, slice_xyz):
        x, y, z = xyz
        s = ax.plot_surface(x, y, z, facecolors=img**0.75, 
            rstride=50, cstride=50)
        surflist.append(s)

    return fig, ax, surflist

不幸的是，如果我设置rstride=1, cstride=1以便以全分辨率显示纹理，这会变得极其缓慢.

Unfortunately this becomes extremely slow if I set rstride=1, cstride=1 in order to display the textures at full resolution.

我也知道 Mayavi 可以轻松处理显示多个2D纹理完整分辨率:

I'm also aware that Mayavi can easily handle displaying multiple 2D textures at full resolution:

from mayavi import mlab

def plot_stack_slices2(stack, scale=(1., 1., 20.), z_interval=10.):

    mfig = mlab.figure(bgcolor=(1,)*3)

    sx, sy, sz = scale
    nz, ny, nx = stack.shape

    slices = stack[::-z_interval]
    slice_z = np.linspace(0,nz*sz,nz)[::z_interval]

    surflist = []

    for (img,z) in zip(slices, slice_z):
        im = mlab.imshow(img.T, colormap='gray', figure=mfig)
        im.actor.scale = [sx,sy,sz]
        im.actor.position = [0, 0, z]
        surflist.append(z)


    return fig, surflist

但是，现在的问题是，似乎没有任何方法可以使用Mayavi显示真彩色RGB纹理-

However, the problem now is that there does not seem to be any way of displaying true-colour RGB textures using Mayavi - according to the docs I can only specify either a single (R, G, B) tuple, or a pre-defined colourmap.

有人知道在3D图中显示真彩色2D RGB纹理的更好方法吗?

如果有足够的时间，我可能会想出如何在Vtk甚至是纯OpenGL中进行此操作，但我真的希望有现有的库来完成这项工作.

Given enough time I could probably figure out how do do this in Vtk or even pure OpenGL if necessary, but I'm really hoping that there are existing libraries that will do the job.

推荐答案

非常感谢aestrivex使用Mayavi/VTK提供可行的解决方案-这是有用的信息，将来我可能需要做一些更复杂的事情.

Big thanks to aestrivex for providing working solutions using Mayavi/VTK - it's useful info that I may need for doing more complicated things in the future.

最后，我实际上选择了cgohlke的建议，即使用 visvis ，实施起来要简单得多:

In the end I actually chose to go with cgohlke's suggestion of using visvis, which turned out to be a lot simpler to implement:

import visvis as vv
vv.use('wx')

import numpy as np
from matplotlib.image import imread
from matplotlib.cbook import get_sample_data

imgdata = imread(get_sample_data('lena.png'))

nr, nc = imgdata.shape[:2]
x,y = np.mgrid[:nr, :nc]
z = np.ones((nr, nc))

for ii in xrange(5):
    vv.functions.surf(x, y, z*ii*100, imgdata, aa=3)

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