3D object as cutout alpha/transparency mask

Unity Engine
1

Hi,

I want to fade out the rim of my scene in all 3 dimensions with a movable 3D sphere as an effector for the visible parts. Everything inside the sphere is visible. Everything outside not. Is that possible?

Something like the alpha cutout like here just as a global scene 3D effect? Best would be with a soft falloff:

Here is the workflow in C4D shown:

Any ideas, scripts or plugins out there? Maybe using culling to cut away objects outside the sphere?

Cheers

2

It’s not really possible to do this with another 3D mesh in the scene. Rather the solution would be to use a shader that calculates the distance to a point in the world that you pass to the shader, and fade in/out based on that calculation.

There are some excellent examples of how to do this here:

Those examples all use noise and a alpha test shader, but it could be made soft by just switching to alpha blending.

3

Hi bgolus,

that is getting very close. Thanks a lot man!