Way to sample a material by clicking on a point?

Basically what I am trying to do is have a character move about a landscape, and then have a very low resolution scene texture map out their movements on a render target. The render target will then map to a mask on the landscape just walked on.

My question is then, is there a method to sample the color of the render target wherever you click on the landscape. In other-words, is there blueprint functionality for a sort of MS paint eye dropper function when using the cursor, so wherever you click it would give you as output the color at that point? Or if that is not possible, how could you track where on a landscape material the mouse cursor clicks, and then using location inputs test the color of a material? Thanks.