How to visualize color gamut boundary mesh and its sample points?

[hminle]

Hi,

I am trying to visualize the color gamut boundary mesh and some sample points in this gamut.
But I met some issues with the mesh, it uses weird unit. Like in CIE Lab, L ranges from 0-1, ab ranges from -127 to 127, but the mesh only from 0-1. Is there any way to control that?

For example, I choose to visualize the sRGB mesh and its sample in CIE Lab like this:

extent = 127
xvalues = np.linspace(-extent, extent, 128)
yvalues = np.linspace(-extent, extent, 128)
zvalues = np.linspace(-extent, extent, 128)

xx, yy, zz = np.meshgrid(xvalues, yvalues, zvalues)
lab_volume = np.vstack([xx.reshape(-1), yy.reshape(-1) ,zz.reshape(-1)]).T

ILLUMINANT_D65 = colour.CCS_ILLUMINANTS['CIE 1931 2 Degree Standard Observer']['D65']
srgb_colourspace = colour.models.RGB_COLOURSPACE_sRGB
XYZ = colour.Lab_to_XYZ(lab_volume, 
                            illuminant=ILLUMINANT_D65)
    
rgb_mask = colour.models.XYZ_to_RGB(XYZ, 
                 srgb_colourspace.whitepoint, 
                 srgb_colourspace.whitepoint,
                 srgb_colourspace.matrix_XYZ_to_RGB)

in_gamut_mask = lab_volume[np.all((mask >= 0) & (mask <= 1), axis=-1)]

fig, ax = colour.plotting.plot_RGB_colourspaces_gamuts(
    'sRGB',
    reference_colourspace='CIE Lab',
    face_colours=(0.25, 0.25, 0.25),
    edge_colours=(0.25, 0.25, 0.25),
    edge_alpha=[0.1],
    face_alpha=[0.0],
    standalone=False,
)
ax.scatter(ig_prop_lab[:,1], ig_prop_lab[:, 2], ig_prop_lab[:, 0])

And the figure: