Line Renderer water reflection issue

Okay, I made a few tests and found a workaround.

Actually I think that linerenderer geometry is dynamically computed to match the orientation of the main camera (the polygons always face the main camera). However, when we use a water shader, the camera used for reflection doesn't recompute the linerenderer orientation. Thus, in the reflection we see the "other side" of the linerenderer. Sadly, most materials in Unity are only 1-sided.

A trick is to use a two-sided material shader, such as this one:

 Shader "Custom/UnlitCutout2Sided" 
 {
     Properties
     {
         _TintColor ("Tint Color", Color) = (1,1,1,1)
         _MainTex ("Base (RGB) Trans. (Alpha)", 2D) = "white" { }
         _CutOff ("Alpha cutoff", Range(0,1)) = 0.5
     }
     
     SubShader {
         Tags { "Queue"="AlphaTest" "IgnoreProjector"="True" "RenderType"="TransparentCutout"}
         ZWrite On
         Cull Off
         AlphaTest Greater 0.5
 
         Pass {
             Lighting Off
             CGPROGRAM
             
             #pragma vertex vert_img
             #pragma fragment frag
 
             #include "UnityCG.cginc"
 
             uniform sampler2D _MainTex;
             float4 _TintColor; 
                         
             half4 frag(v2f_img i):COLOR
             {
                 return _TintColor*tex2D(_MainTex, i.uv);
             }
             ENDCG
         }
     } 
     Fallback "Transparent/Cutout/Diffuse"
   }

You can use a lot of different shaders, the important part is "Cull Off" which renders both sides of a mesh. I don't know if Unity provides default 2-sided shaders, but, if it does, they should do the job as well.

Maybe it's not the best solution, but it kinda works for me. I hope it helps :)

Peace.