Prevent Interaction through actors

I was following this tutorial on how to create a reliable interaction system that allows the player to choose which object to interact with based on vectors (Let's Make: An Interaction System: Part 1 - YouTube). His system works perfectly fine and it provided all the utility that I needed from an interaction system.
However, my biggest issue is that the player can still interact with the objects even if there’s a wall between the object and the player. How do you make it so that the player cannot interact with the object if there’s a ‘solid actor’ between the player and the object? Is there a setting that I need to enable, like how there’s one for collision?
Side Note: If we imagine a scenario where there’s a box and in front of it there’s a pillar, the player can still interact with the box if he/she look next to the pillar and see the box while standing in front of it (while the box is covered and on the other side). So I want it to be based off the mesh of the ‘solid object’ rather than based off of a trigger box or a location value.