Simple Billboard shader for Unity

billboard.shader

Shader "Unlit/Billboard"
{
	Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
	}
	SubShader
	{
		Tags{ "Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent" "DisableBatching" = "True" }

		ZWrite Off
		Blend SrcAlpha OneMinusSrcAlpha

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			// make fog work
			#pragma multi_compile_fog

			#include "UnityCG.cginc"

			struct appdata
			{
				float4 vertex : POSITION;
				float2 uv : TEXCOORD0;
			};

			struct v2f
			{
				float2 uv : TEXCOORD0;
				UNITY_FOG_COORDS(1)
				float4 pos : SV_POSITION;
			};

			sampler2D _MainTex;
			float4 _MainTex_ST;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.pos = UnityObjectToClipPos(v.vertex);
				o.uv = v.uv.xy;

				// billboard mesh towards camera
				float3 vpos = mul((float3x3)unity_ObjectToWorld, v.vertex.xyz);
				float4 worldCoord = float4(unity_ObjectToWorld._m03, unity_ObjectToWorld._m13, unity_ObjectToWorld._m23, 1);
				float4 viewPos = mul(UNITY_MATRIX_V, worldCoord) + float4(vpos, 0);
				float4 outPos = mul(UNITY_MATRIX_P, viewPos);

				o.pos = outPos;

				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				// sample the texture
				fixed4 col = tex2D(_MainTex, i.uv);
				// apply fog
				UNITY_APPLY_FOG(i.fogCoord, col);
				return col;
			}
			ENDCG
		}
	}
}

The direction is not towards the camera further it is only billboard the mesh not its collider

The direction is not towards the camera further it is only billboard the mesh not its collider

How could a shader program (which executes on the GPU as part of the graphics pipeline) possibly access and manipulate the physics collider data??? Short answer: it can't