Question Novice Shader Question

Hello. I am trying to learn to write my own shaders and I've gotten to where I want to start using _CameraDepthTexture. In particular, I want to write my own logic to do an outline and I'd like to use that texture among others.

What I want to do right now: render specific layer of objects as their depth.

Where I am at: (The cube is the only object on the layer to be displayed as depth)

As you can see, the cube is taking the entire depth texture and painting it on each face, but I only want the cube's portion of that texture to be painted.

Relevant Settings:



The Shader Code:

Code (CSharp):

1.  
2. Shader "Unlit/DepthShade"
3. {
4.     Properties
5.     {
6.         _MainTex ("Texture", 2D) = "white" {}
7.     }
8.  
9.     SubShader
10.     {
11.         Tags { "RenderType"="Opaque" }
12.         LOD 100
13.  
14.         Pass
15.         {
16.             CGPROGRAM
17.             #pragma vertex vert
18.             #pragma fragment frag
19.             // make fog work
20.             #pragma multi_compile_fog
21.  
22.             #include "UnityCG.cginc"
23.  
24.             struct appdata
25.             {
26.                 float4 vertex : POSITION;
27.                 float2 uv : TEXCOORD0;
28.             };
29.  
30.             struct v2f
31.             {
32.                 float2 uv : TEXCOORD0;
33.                 float4 vertex : SV_POSITION;
34.             };
35.  
36.             sampler2D _MainTex;
37.             float4 _MainTex_ST;
38.             sampler2D _CameraDepthTexture;
39.             float4 _CameraDepthTexture_ST;
40.  
41.             v2f vert (appdata v)
42.             {
43.                 v2f o;
44.                 o.vertex = UnityObjectToClipPos(v.vertex);
45.                 o.uv = TRANSFORM_TEX(v.uv, _MainTex);
46.  
47.                 return o;
48.             }
49.  
50.             fixed4 frag (v2f i) : SV_Target
51.             {
52.                 // sample the texture
53.                 fixed4 col = tex2D(_CameraDepthTexture, i.uv);
54.                
55.                 return col.r;
56.             }
57.             ENDCG
58.         }
59.     }
60. }
61.  

I am assuming I should transform the UV coordinates but I just don't know what to do to them.
Any help is appreciated.

 

...for anybody else who ends up here - what you want to do is use ComputeGrabScreenPos to get the correct coordinates to sample the depth texture.

Here are a couple of links that helped me.
https://forum.unity.com/threads/how...en-space-in-framgment-shader-function.219843/

https://docs.unity3d.com/Manual/SL-GrabPass.html

and the shader code I used that produced the result I wanted.

Code (CSharp):

1. Shader "Unlit/DepthShade"
2. {
3.     Properties
4.     {
5.         _MainTex ("Texture", 2D) = "white" {}
6.     }
7.  
8.     SubShader
9.     {
10.         Tags { "RenderType"="Opaque" }
11.         LOD 100
12.  
13.         Pass
14.         {
15.             CGPROGRAM
16.             #pragma vertex vert
17.             #pragma fragment frag
18.             // make fog work
19.             #pragma multi_compile_fog
20.  
21.             #include "UnityCG.cginc"
22.  
23.             struct appdata
24.             {
25.                 float4 vertex : POSITION;
26.                 float2 uv : TEXCOORD0;
27.             };
28.  
29.             struct v2f
30.             {
31.                 float2 uv : TEXCOORD0;
32.                 float4 grabPos : TEXCOORD1;
33.                 float4 vertex : SV_POSITION;
34.             };
35.  
36.             sampler2D _MainTex;
37.             float4 _MainTex_ST;
38.             sampler2D _CameraDepthTexture;
39.             float4 _CameraDepthTexture_ST;
40.  
41.             v2f vert (appdata v)
42.             {
43.                 v2f o;
44.                 o.vertex = UnityObjectToClipPos(v.vertex);
45.                 o.uv = TRANSFORM_TEX(v.uv, _MainTex);
46.                
47.                 o.grabPos = ComputeGrabScreenPos(o.vertex);
48.  
49.                 return o;
50.             }
51.  
52.             fixed4 frag (v2f i) : SV_Target
53.             {
54.                 // sample the texture
55.                 fixed4 col = tex2Dproj(_CameraDepthTexture, i.grabPos);
56.                
57.                 return col.r;
58.             }
59.             ENDCG
60.         }
61.     }
62. }
63.