Question Depth texture visualize shader

Hi there!

I'm currently learning how to write shaders in Unity. I've been following some tutorials on how to write a shader that utilizes depth texture in URP, but unfortunately, I'm unable to achieve the same result as in the tutorial for some unknown reasons. It seems that SampleSceneDepth always returns 0, regardless of the position of my test object.

To check this idea, I decided to write a simple shader that would visualize the depth texture. However, for some reason, the color returned by the shader is always black. I have already enabled the DepthTexture checkbox on the URP asset. Here's the code for my shader. Can anyone please tell me what I did wrong?

Code (CSharp):

1. Shader "Custom/DepthTextureVisualize"
2. {
3.     Properties {}
4.     SubShader
5.     {
6.         Tags
7.         {
8.             "RenderType" = "Opaque"
9.             "RenderPipeline" = "UniversalPipeline"
10.         }
11.  
12.         Pass
13.         {
14.             HLSLPROGRAM
15.             #pragma vertex vert
16.             #pragma fragment frag
17.            
18.             #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
19.             #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DeclareDepthTexture.hlsl"
20.            
21.             struct appdata
22.             {
23.                 float4 positionOS : POSITION;
24.             };
25.  
26.             struct v2f
27.             {
28.                 float4 positionHCS : SV_POSITION;
29.             };
30.            
31.             v2f vert(appdata IN)
32.             {
33.                 v2f OUT;
34.                 OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);
35.                 return OUT;
36.             }
37.            
38.             float4 frag(v2f IN) : SV_Target
39.             {
40.                 float2 UV = IN.positionHCS.xy / _ScaledScreenParams.xy;
41.                 float depth = SampleSceneDepth(UV);
42.  
43.                 return float4(depth, depth, depth, 1.0);
44.             }
45.             ENDHLSL
46.         }
47.     }
48. }

 

In case if someone has the same situation in future. I found solution - it appeared that in my scene existed only objects with my shaders, which do not write to ZBuffer and as far as I understood that was the reason, why depth texture was black. After adding objects with Lit URP shaders everything started to work.