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This cone sight line of enemy how to make.
I haven’t got a way up to now.
The video show :好尸【影子战术：将军之刃】攻略解说第一期 - YouTube
Maybe could make a MeshDataTypeEmitter. Create the shape with like a plane in your 3d modeling program, and then in cascade you could apply a translucent material and place the emitter on the NPC.
looks like it’s either a light or a decal or a combination of the two.
from the video it seems that when the character faces a direction where the line of sight is blocked a ring pattern appears, so that makes me think its a light. however the light isn’t showing up on the sides of the buildings so they are either somehow masking it out based on the world normal, which I don’t know if that can be done, or they are using a separate light channel.
here’s some stuff that may help you figure it out.
if you use spot lights you’ll need to mess with the fall off settings.