IndexError when running the "textured gyroid shape" example

Running this example:

vedo -r gyroid

gives me IndexError: list index out of range error:

gyroid - A textured gyroid shape cut by a sphere from vedo import..
(/Users/matus/miniconda3/envs/3d-vis/lib/python3.9/site-packages/vedo/examples/advanced/gyroid.py)
Traceback (most recent call last):
  File "/Users/matus/miniconda3/envs/3d-vis/lib/python3.9/site-packages/vedo/examples/advanced/gyroid.py", line 10, in <module>
    gyr = Volume(U).isosurface(0).smoothLaplacian().subdivide()
  File "/Users/matus/miniconda3/envs/3d-vis/lib/python3.9/site-packages/vedo/volume.py", line 1025, in __init__
    self.mode(mode).color(c).alpha(alpha).alphaGradient(alphaGradient)
  File "/Users/matus/miniconda3/envs/3d-vis/lib/python3.9/site-packages/vedo/base.py", line 1466, in color
    r,g,b = colors.colorMap(x, name=col, vmin=smin, vmax=smax)
  File "/Users/matus/miniconda3/envs/3d-vis/lib/python3.9/site-packages/vedo/colors.py", line 651, in colorMap
    return hex2rgb(cmap[n-iv])
IndexError: list index out of range

[MatusGasparik]

I am on macOS:

os.uname()

posix.uname_result(sysname='Darwin', nodename='Foo-MacBook-Pro.local', release='20.5.0', version='Darwin Kernel Version 20.5.0: Sat May  8 05:10:33 PDT 2021; root:xnu-7195.121.3~9/RELEASE_X86_64', machine='x86_64')

with python==3.9.5. I haven’t checked all examples, but most of them work as expected.

I ran the script with the pdb:

python -m pdb -c continue /Users/matus/miniconda3/envs/3d-vis/lib/python3.9/site-packages/vedo/examples/advanced/gyroid.py

Here is the output:

(Pdb) ll
587  	def colorMap(value, name="jet", vmin=None, vmax=None):
588  	    """Map a real value in range [vmin, vmax] to a (r,g,b) color scale.
589
590  	    :param value: scalar value to transform into a color
591  	    :type value: float, list
592  	    :param name: color map name
593  	    :type name: str, matplotlib.colors.LinearSegmentedColormap
594
595  	    :return: (r,g,b) color, or a list of (r,g,b) colors.
596
597  	    .. note:: Most frequently used color maps:
598
599  	        |colormaps|
600
601  	        Color maps list:
602
603  	        .. image:: https://matplotlib.org/1.2.1/_images/show_colormaps.png
604
605  	    .. tip:: Can also use directly a matplotlib color map:
606
607  	        :Example:
608  	            .. code-block:: python
609
610  	                from vedo import colorMap
611  	                import matplotlib.cm as cm
612  	                print( colorMap(0.2, cm.flag, 0, 1) )
613
614  	                (1.0, 0.809016994374948, 0.6173258487801733)
615  	    """
616  	    value_isSequence = False
617  	    if _isSequence(value):
618  	        value_isSequence = True
619  	        values = np.array(value)
620  	        if vmin is None:
621  	            vmin = np.min(values)
622  	        if vmax is None:
623  	            vmax = np.max(values)
624  	        values = np.clip(values, vmin, vmax)
625  	        values -= vmin
626  	        values = values / (vmax - vmin)
627
628  	    # matplotlib not available #######################
629  	    if not _has_matplotlib:
630  	        invert=False
631  	        if name.endswith('_r'):
632  	            invert=True
633  	            name = name.replace('_r', "")
634  	        cmap = cmaps[name]
635
636  	        n = len(cmap)-1
637  	        if value_isSequence:
638  	            outs = []
639  	            for v in values:
640  	                iv = min(255, int(v*n))
641  	                if invert:
642  	                    rgb = hex2rgb(cmap[n-iv])
643  	                else:
644  	                    rgb = hex2rgb(cmap[iv])
645  	                outs.append(rgb)
646  	            return outs
647
648  	        else:
649  	            iv = min(255, int(value*n))
650  	            if invert:
651  ->	                return hex2rgb(cmap[n-iv])
652  	            else:
653  	                return hex2rgb(cmap[iv])
654
655  	    # matplotlib is available, use it! #######################
656  	    if isinstance(name, matplotlib.colors.LinearSegmentedColormap):
657  	        mp = name
658  	    else:
659  	        mp = cm_mpl.get_cmap(name=name)
660
661  	    if value_isSequence:
662  	        mp = cm_mpl.get_cmap(name=name)
663  	        return mp(values)[:,[0,1,2]]
664  	    else:
665  	        value -= vmin
666  	        dv = vmax - vmin
667  	        if dv:
668  	            value /= dv
669  	        if value > 0.999:
670  	            value = 0.999
671  	        elif value < 0:
672  	            value = 0
673  	        return mp(value)[0:3]
(Pdb) p iv
-381
(Pdb) p n
255

The iv value seem to be the issue…

[marcomusy]

Ahhh !! Right I will add a more meaningful error message…