Get Z-Map of another Camera

Unity Engine
, ,
1

Hi, I’m encountering issues with the depth texture of my second Camera. I’m currently trying to get the Z-map of my second camera and use it in a custom shader, however I’m not able to find a way in order to realize this.
I tried to use the “_LastCameraDepthTexture” like this :

Shader "RenderDepth" {

    SubShader
    {
        Pass
        {
            cull off
            ZWrite On
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"       
             
            sampler2D _LastCameraDepthTexture;
            v2f_img vert(appdata_img v)
            {
                return vert_img(v);
            }
            float4 frag(v2f_img i) : COLOR
            {
                float depth = tex2D(_LastCameraDepthTexture, i.uv.xy);
                depth = Linear01Depth(depth);
                return float4(depth, depth, depth,1);
            }
            ENDCG
        }
    }
        FallBack "Diffuse"
}

I tried to make a render texture with the depth buffer only :

using UnityEngine;
using System.Collections;
using UnityEngine.Rendering;
[RequireComponent(typeof(Camera))]
public class DepthCameraManager : MonoBehaviour
{
    [SerializeField] private RenderTexture target = null;
    [SerializeField] private RenderTexture targetDepth = null;
    [SerializeField] private Vector2Int _rangeWithHeight = new Vector2Int(256, 256);
    [SerializeField] private Material _mat;

    void Start()
    {
        Camera camera = GetComponent<Camera>();
        camera.depthTextureMode = camera.depthTextureMode | DepthTextureMode.Depth;

        target = new RenderTexture(_rangeWithHeight.x, _rangeWithHeight.y, 0, RenderTextureFormat.Default);
        targetDepth = new RenderTexture(_rangeWithHeight.x, _rangeWithHeight.y, 24, RenderTextureFormat.Depth);
       
        camera.SetTargetBuffers(target.colorBuffer, targetDepth.depthBuffer);

        _mat.SetTexture("_DepthTexture", targetDepth);
    }
}

I’m pretty sure I’m missing something, maybe some camera parameters or render texture parameters. Perhaps I need to make a blit in a custom render pass. But I don’t find any clues. I’m currently using Unity URP 2022.3. Thanks for your help, I can provide you more details if needed.