3D imshow?

I am currently using Mayavi to show 3D microscopy images using ```points3d``` by displaying pixels above a threshold intensity while ignoring all other pixels. The resulting image resembles a 3D equivalent of the microscopy images I would see using ```imshow``` in Matplotlib, but I have had difficulty rendering points to look like the original pixels. Here is an example of the original 2D image (left) and the 3D image of the yellow box area using ```points3d``` rendered in Mayavi (right):


Sphere and cube glyphs are the closest I have found to resemble pixels but appear "bubbly" or "blocky" compared with the original pixels. Interpolation or smoothing might help. Is there a 3D equivalent function to ```imshow``` in Mayavi, or a way to render points closer to pixels in the original underlying stack of images?