@seachnasaigh I've found @Snarlygribbly 's Particles3+ particle system which does appear to still work in Poser Pro 11.1, so I'll have a go with that and see if I can constrain it's particle emitter to the figure's mouth and use my material with it's PRT3_Life node as the driver for the Scatter Volume Density via some math transformations to match my valueOperation Key profile. I'll probably also see if the source code is amenable to taking into account Poser UI units setting so it's a bit less impenetrable. @amethystpendant unfortunately, there doesn't appear to be any way to identify either the constraint parameters or the constraint target actor or client from within Poser Python, as yet. (Attention @Poser-Team we need full Python exposure and operability for new features when they are released, not decades to never!)