sample material function at specific coordinates?

I have a material function generating waves

I’d like to sample the height of the waves at specific points relative to an intersecting actor

… How might I do this in a blueprint? probably obvious, but Im a noob, apologies


To clarify:

  • ive set up a material function to generate Gerstner waves (thanks Handkor)
  • In order to mimic bouyancy and have objects sliding down waves Id like to sample the wave height at points relative to the floating object’s centre
  • Im trying to do it in blueprints

Q how can you sample the output of a material function at specific points, in a blueprint?

i.e. return (value of property x) from material function(MF_given) at (x,y)

Ive trawled the documentation and you would think that it would be a fairly common thing to do,
but I cant see it

One way is to use a RenderTarget, but I gather but this is expensive
[PS I am aware of the excellent work at the [Community Project] WIP Weather & Water Shader - Game Development - Epic Developer Community Forums and have also posted this question there]

Perhaps it cannot be done in only a blueprint, requires code?