Sorry, I have just found the description for sides N sides N The number of straight-line segments used to draw an <https://www.cgl.ucsf.edu/chimerax/docs/user/commands/cartoon.html#xsection> oval cross-section or the circumference of a <https://www.cgl.ucsf.edu/chimerax/docs/user/commands/cartoon.html#hmode> tube, with higher numbers corresponding to finer subdivisions (initial default 12). Shading is used to give a smooth, rounded appearance despite this approximation of the shape. See also: <https://www.cgl.ucsf.edu/chimerax/docs/user/commands/graphics.html#quality> graphics quality https://www.cgl.ucsf.edu/chimerax/docs/user/commands/cartoon.html#hmode Best wishes, Winston From: Wen-Jin Winston Wu [mailto:winston@gate.sinica.edu.tw] Sent: Friday, July 2, 2021 2:27 PM To: ChimeraX-users@cgl.ucsf.edu Subject: how to change the radius of loop Hello, Does anyone know how to modify the radius of loops? I am trying to show structural difference between the three aligned proteins with the cartoon helices shown as tubes. However, when I reduced the helix radius from 2 to 1 ( "cartoon style modeh tube rad 1 sides 24"), the radius of a helix is only about twice that of a loop/coil. Also, what does the number "24" do in the "sides 24"?. I could not find the description on this on ChimeraX Any help will be appreciated. Thanks, Best wishes, Winston