in (/vispy/visuals /surface_plot.py) line 129

[Abbas-Yasir]

    if colors.ndim == 3:
        # convert (width, height, 4) to (num_verts, 4)
        vert_shape = self.__vertices.shape
        num_vertices = vert_shape[0] * vert_shape[1]
        colors = colors.reshape(num_vertices, **_3_**)
    return colors

Shouldn't:
colors = colors.reshape(num_vertices, 3)
be
colors = colors.reshape(num_vertices, 4) ????

[djhoese]

FYI you can link to exact lines and line ranges with a github URL. You can even use a "permalink" and github will show a preview of the code in your comment. Here is what you are referencing:

vispy/vispy/visuals/surface_plot.py

Lines 121 to 130 in c366456

	def _prepare_mesh_colors(self, colors):
	if colors is None:
	return
	colors = np.asarray(colors)
	if colors.ndim == 3:
	# convert (width, height, 4) to (num_verts, 4)
	vert_shape = self.__vertices.shape
	num_vertices = vert_shape[0] * vert_shape[1]
	colors = colors.reshape(num_vertices, 3)
	return colors

Let me review the code and see what I think. I feel like this came up in another issue recently.

[djhoese]

Overall I think you're right. However, two things:

1. This should have raised an error as it is with every usage of RGBA colors being passed. So people must have gotten used to only passing RGB colors. If you used 4 in the reshape call and the input was RGB (3 element color) then it would fail.
2. Instead of 4, it should just be -1 and numpy will put whatever remaining elements there are in that last dimension. Or it could be colors.shape[-1] which is maybe a bit less error prone. Actually, it could be .reshape((-1, colors.shape[-1])) and then that num_vertices call doesn't need to happen at all...but I suppose that validates that colors are the same size.

Anyway, the mesh converts RGB (3) to RGBA (4) here inside the mesh:

vispy/vispy/geometry/meshdata.py

Lines 14 to 18 in c366456

	if colors.shape[-1] == 3:
	pad = np.ones((len(colors), 1), colors.dtype)
	if colors.ndim == 3:
	pad = pad[:, :, np.newaxis]
	colors = np.concatenate((colors, pad), axis=-1)

I'd appreciate a pull request with changing the 3 to a -1 if you're up to it?