Transparency in front of player

So I'm trying to create a shader that takes in a vector and and creates a transparent circle in front of this vector. Here is the significant code regarding it.

 Vert
 o.pos = UnityObjectToClipPos(v.vertex);
 o.screenPos = ComputeScreenPos(o.pos);
 o.transScreenPos =ComputeScreenPos( UnityObjectToClipPos(mul(unity_WorldToObject, _TransparentPosition)));
                 
 Frag
 i.screenPos.xyz /= i.screenPos.w;
 i.transScreenPos.xyz /= i.transScreenPos.w;
 if (length(i.screenPos.xy - i.transScreenPos.xy)<_TransparencySize)

In the game, however there are unique circles for each object using the shader and it isn't centered on the vector. Thanks for your time.