I am using Asymptote to create 3D graphics, which I export to PNG-files. I would like to have a transparent background in the PNG-file.
For 2D graphics, I can easily get a transparent background when I export from Asymptote. However, for 3D graphics I have so far been unable to get a transparent background.
I have tried
currentlight.background=opacity(0.0)+rgb(255,255,255);
but this just produces a white background in the PNG-file.
Does anybody know if it is possible to obtain a transparent background when exporting 3D graphics from Asymptote to a 2D rendered file format?