This effect makes all intersecting portions of BaseParts into a specific color. I believe this is from some sort of trick, since it works with Parts and MeshParts (so it’s not some coded part replacement thing).
This might be relevant, when the camera goes under the “water” this effect goes away:
As can be seen above, it works with the head mesh, which is either a SpecialMesh or MeshPart.
It also works with different shapes of Parts, like wedges:
As can be seen below, it definitely works with MeshParts:
Please let me know if you can think of any ways this was accomplished or if you know the trick to doing this. (I imagine it has something to do with some of the newer materials (Neon, ForceField, Glass), transparency, reflection, SurfaceAppearance, or Colors greater than 255,255,255.) Any help is appreciated!
It almost looks like 2 semi-transparent decals on 2 Parts with one about .1 stud higher, since the edge of the wall or the player has 2 shades of blue slightly separate. If the decals were on the top face but there was only one on a bottom surface then the effect would be different when seen from underneath.
I was thinking something similar. I put the camera right between the two surfaces though and it didn’t make a difference (the top surface became invisible and the effect was still happening).
Edit:
In this screen grab the camera is right between the two layers:
Apparently there is some sort of max transparency, and once you reach that the shapes stop being increasingly hidden, but the change in color change continues to increase.
I’ll edit this reply in a bit and add how to accomplish this and what the limitations are.
Edit:
It only works with future lighting. To do it set the transparency of a part to about 0.100001 or stack a few parts with transparencies greater than 0.1.
Edit:
You can do some pretty interesting stuff with this: