How can I make a transparent ground, that hides other objects beneath it?

Questions & Answers
1

I am making AR App. I’m in trouble with an animation that pond is created, fish come up and goes down and disappear. I did the rest of it but the fish is visible under the pond. Since it’s an AR App, the whole animation shouldn’t just cover the Screen. So what I thought is, I should just make a totally transparent plane and make it hide objects underneath it.(make other objects under plane invisible.) (Maybe just render upper parts of plane?) But I really couldn’t figure out how to do it. Is there anyway to do it?

2

I found the solution here
https://gamedev.stackexchange.com/questions/172656/how-to-hide-objects-behind-an-invisible-plane

i needed custom shader

Shader "Custom/DepthReserve"
{
    Properties
    {
    }
    SubShader
    {
        Tags { "RenderType" = "Opaque" "Queue"="Geometry-1" }
        LOD 100

        Blend Zero One

        Pass
        {

        }
    }
}

Applying this shader to material, any object can be transparent and also hide other object beneath it.