Hi
I've a shader which is just a water displacement map for raindrops - the scale of the displacement map on some glass textured geometry is driven by a vertex map, so some areas of a geo (a bottle) have raindrops and a central area doesn't, with good fade etc., and the raindrops set to water IOR with the glass at Glass IOR, for that lovely look. Geo has two Arnold SubD iterations and autobump enabled.
The raindrops are set to alpha stack with the glass material underneath, the stacking driven by 'Shader' set to 'Displacement', then the vertex map acts as a paintbrush for where that alpha should be and how high to push the displacement.
I've noticed that if I enable 'specular transmission' in the autobump visibility options, the result is gorgeous, but for some reason the areas otherwise 'masked out' by the vertex map so there is no displacement scale at 0% (and and therefore no raindrops) ...the raindrops are visible (or at least the spec transmission is) ...that setting seems to override or disregard the scale?
Any way around this?
Thanks, can provide test scene if that would help a bit.