How to add lighting when a stl file is displayed using mplot3d?

[n2d7]

Hi, Is there a way to add lighting when displaying an stl file with mplot3d? In mplot3d, lighting is added for a surface plot in this manner.

rgb = np.ones((Z.shape[0], Z.shape[1], 3))
illuminated_surface = light.shade_rgb(rgb, Z)
ax = Axes3D(plt.figure())
ax.plot_surface(X, Y, Z, rstride=1, cstride=1, linewidth=0, antialiased=False,
                facecolors=illuminated_surface)

but I'm not sure how to pass the parameters in ax.add_collection3d(mplot3d.art3d.Poly3DCollection(new_mesh.vectors))

appreciate any help

[wolph]

Perhaps with the lightsource parameter to plot_surface? I'm not really sure, I don't know too much about matplotlib :)

https://matplotlib.org/stable/tutorials/toolkits/mplot3d.html#mpl_toolkits.mplot3d.Axes3D.plot_surface

[mooomooo]

This is the function I use. It sometimes does some weird things where faces that should be hidden peek through faces that are in the front. I'm not sure if that's a bug in matplotlib or my code or what; if anyone has any suggestions on how to fix that, I'd be happy to hear.

import numpy
from stl import mesh
from mpl_toolkits import mplot3d
from matplotlib import pyplot
from matplotlib.colors import LightSource

def plotSTL(filename):
    # Create a new plot
    figure = pyplot.figure()
    axes = mplot3d.Axes3D(figure)

    # Load the STL mesh
    stlmesh = mesh.Mesh.from_file(filename)
    polymesh = mplot3d.art3d.Poly3DCollection(stlmesh.vectors)

    # Create light source
    ls = LightSource(azdeg=225, altdeg=45)

    # Darkest shadowed surface, in rgba
    dk = numpy.array([0.2, 0.0, 0.0, 1])
    # Brightest lit surface, in rgba
    lt = numpy.array([0.7, 0.7, 1.0, 1])
    # Interpolate between the two, based on face normal
    shade = lambda s: (lt-dk) * s + dk

    # Set face colors 
    sns = ls.shade_normals(stlmesh.get_unit_normals(), fraction=1.0)
    rgba = numpy.array([shade(s) for s in sns])
    polymesh.set_facecolor(rgba)

    axes.add_collection3d(polymesh)

    # Adjust limits of axes to fill the mesh, but keep 1:1:1 aspect ratio
    pts = stlmesh.points.reshape(-1,3)
    ptp = max(numpy.ptp(pts, 0))/2
    ctrs = [(min(pts[:,i]) + max(pts[:,i]))/2 for i in range(3)]
    lims = [[ctrs[i] - ptp, ctrs[i] + ptp] for i in range(3)]
    axes.auto_scale_xyz(*lims)

    pyplot.show()

[stale[bot]]

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[rcarmo]

I landed here looking for the same thing, after getting really close to the sample function shown. Is there a good way to do this using solely LightSource and Poly3DCollection? I can get rid of edges, but shading facets (and culling invisible ones) is a major pain.