Is it possible to fill volumetric gradients in adobe dimensions. For example a transparent cylinder with high color density on the axis and the transparency falls off away from the axis. (I want to creat a 3d laser beam using dimensions).
Not sure. I have similar task in the past and went to After Effects to add laser beam to my image. Or you can render Ps file from Dn then open Ps and use Lighting Effect from Filters to achive desire effect.
yes and no, Transparency maps in Dimension are black or white and yes you can use gradients but they don't look very good because you only have on or off... not really a fade
volumetric gradients are just colour so yes you can have them... imo it sounds like you need to make the 'beam' in Dimension then add the 'fade' \ transparency in after effects or Photoshop