Question Cut (clip) a uniform circle through the level.

EDIT: I solved it. just do
float2 coords = (IN.screenPos.xy / IN.screenPos.w) * _ScreenParams.xy;
float2 mid = _ScreenParams.xy/2;
float circle = -(100 - distance(coords, (mid)));
clip(circle);
To get a 100 pixel radius circle

Code (CSharp):

1.  void surf(Input IN, inout SurfaceOutputStandard o) {
2. ...
3. ...
4. float2 coords= IN.screenPos.xy / IN.screenPos.w;
5. planeDist = 0.5 - distance(coords, (0.5,0.5));
6. clip(-planeDist);
7. }

Hey. So i want to make this circle not streched and lets say it reaches all the way up or half the way up in height regardless of screen resolution, then i would want it to adapt its width to not stretch all the way but rather become a uniform circle. Any other way i should go about this? I know stencil masks work but i would ultimately want to only ignore pixels from the camera up to the main character in a circle around the camera. And I could do that with clip. But maybe not with stencil im thinking. Thx