Culling a weapons iron sights when aiming down a scope? How to?

Hey guys,

Ive been looking into this issue for a while but am unable to find a similar example, the closest ive found is things to do with culling inner triangles using custom depth, but im not entirely sure this is the same issue.

Essentially im wondering how to, if possible, cull the front sight post of my weapon on command so that it is not visible in my scoped ADS. I’ve heard this is possible with masking but again, I feel like Im googling the wrong terms and cant quite find any information that is clearly similar. Does anyone know how to go about this??

Thanks in advance for any help, I appreciate your time massively!

Normally depending on the weapon the iron sight may be visible within the scope - obviously blurred by dept of field.

Either way the only way I can think of is to have All the weapons in a special depth buffer and use a PP not to render it.
if you are using a scene capture it is easier, you just exclude the weapon within it via blueprint.

You could make some sort of WPO based vertex shader trick that shrinks the sights when player is looking down the scope.