Hi Steve, Not easily or necessarily smoothly. Each of those lighting “presets” is a combination of other parameters with certain values, and these parameters can be adjusted with the “lighting” command. You can see the values in each one by applying it and then just using “lighting” without any keywords, for example commands: light soft light light simple light Then the detailed parameters for the soft and simple presets would be shown in the Log. To even attempt to gradually change between the two, you could try combining “perframe” with “lighting” to gradually change individual parameters (intensity, fill intensity, ambient intensity, number of multishadows), but it would be somewhat arduous. <http://rbvi.ucsf.edu/chimerax/docs/user/commands/lighting.html> See perframe, the most analogous example is the one that changes volume contour level: <http://rbvi.ucsf.edu/chimerax/docs/user/commands/perframe.html> A simpler approach: If the scene contents are not moving at all, however, you could just crossfade between an image with light soft and another with light simple (see “movie crossfade” ). I don’t know how good it would look, however. <http://rbvi.ucsf.edu/chimerax/docs/user/commands/movie.html#crossfade> I hope this clarifies, Elaine ----- Elaine C. Meng, Ph.D. UCSF Chimera(X) team Department of Pharmaceutical Chemistry University of California, San Francisco

On Feb 20, 2019, at 2:26 PM, Steve Chou <stevezchou@gmail.com> wrote:

Dear ChimeraX team, Is it possible to change the lighting gradually in ChimeraX, e.g., from "soft lighting" to "lighting simple"? This sounds weird, but makes sense if we want to change the lighting method in a movie. Thanks in advance! Steve