Thread by @kurtruslfanclub

There's a few things we need to do to get wall fades working well

Some of it is purely in-shader and some requires code as well

[thread]

https://twitter.com/daneobyrd/status/1317524620656902144

we have a really simple shader function we can add to any objects that might block the camera, and it fades out opacity of objects based on the player's screen position.

it's a good fallback when we want trees or roofs to never really block the player's view of action

but if we turn off the screen space fade, this is the code-based fade

we do a line trace from the pawn to the camera and any blueprint/prefab the trace hits gets sent the message "in front of player"

any object can implement this interface and handle how to respond

critical additions to this code-based fade are for fading objects that are sitting on the roofs

see here, the papers on the roof are still visible when the roof fades - we need to make sure objects placed on fadeable platforms are correctly assigned to their parent

what we've done here to compensate are that when we do level design we assign objects to their parent structure

for characters and monsters, we check per frame what we're standing on and update our platform so we'll fade out with the parent structure when the player needs

so for all objects on roofs we hide them when the roof is hidden

We support any object in the game being hidden like this so it's sometimes a pop-out to just turn off visibility, but with the radial blend as well it seems less obvious a pop-out

Last note: probably the most important fact is to ensure, either through code or through your shader, that hidden items are still drawn in the shadow pass

In unreal we put shader fades behind a check for is-in-shadow-pass, and when setting to hidden we turn on bHiddenShadow