traceback using transparency command on map surf colored by zone

[Elaine Meng]

example:
open 4hhb
rainbow
molmap /a 8
color #2 zone #1 dist 5
transp #2 50

Traceback (most recent call last):

File "/Users/meng/Desktop/ChimeraX.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/cmd_line/tool.py", line 205, in execute

cmd.run(cmd_text)

File "/Users/meng/Desktop/ChimeraX.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/cli.py", line 2569, in run

result = ci.function(session, kw_args)

File "/Users/meng/Desktop/ChimeraX.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/transparency.py", line 66, in transparency

surfs = _set_surface_transparency(atoms, objects, session, alpha)

File "/Users/meng/Desktop/ChimeraX.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/commands/transparency.py", line 126, in _set_surface_transparency

s.set_transparency(alpha)

File "/Users/meng/Desktop/ChimeraX.app/Contents/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/chimerax/core/map/volume.py", line 367, in set_transparency

self.update_display()

AttributeError: 'Volume' object has no attribute 'update_display'

[Tom Goddard]

Fixed.

Code was broken a few weeks ago by changes to improve volume display updating.

Transparency command now works on multicolored volume surfaces. The volume command transparency option currently only effects the single color specified for the volume, not ideal, but also not easy to fix.