Doomsky shader

[elvisish]

A couple of years ago, you posted your DoomSky shader on Unity Answers (https://answers.unity.com/questions/1500175/doom-style-billardsprite-skybox-without-perspectiv.html), and I always use it as my default skybox shader, since it has very little cylindrical distortion. I've been trying to figure out how to add a rotation offset to it (like the built-in panoramic shader has) but I've not been able to figure out how exactly. Would it require much reworking to add?

One other question I have, I get an error in Unity "Shader for this material does not support skybox rendering" but it works fine, I just don't know if it matters that I get this error or not.

Thanks again for the amazing shader, it's my go-to every time for skyboxes!

[Bunny83]

Just saw your message ^^.

Well the shader actually already has an x-offset of "0.5" hardcoded in this line:

float2 uv = float2(0.5+atan2(dir.z, dir.x)/(2*UNITY_PI), _StretchDown+dir.y*(1-_StretchDown));

Note that the value for "U" (the x component in our "uv") goes from 0 to 1 however since we expect our texture to be tilable we can happily go beyond those limits. If you want to add an additional offset. just replace the "0.5" with a variable. Keep in mind that a value of 0 and a value of 1 are essentially the same and corresponds to 0° or 360°. To avoid floating point issues of course the value should be kept between 0 and 1.

About that warning you get I can only say that I have never used the shader for the default skybox but only applied it to custom sky brush meshes. According to this question this warning is only a matter of "tagging" the shader as a skybox shader. Though as mentioned I have never tried this.

[elvisish]

Thanks for getting back! I also added the line you suggested uv.x *= 4; to get the right sort of tiling (I changed it to 3) which probably should also be a variable rather than hard-coded: ` Shader "FX/DoomSky" { Properties { _MainTex ("Texture", 2D) = "white" {} _StretchDown ("Stretch", Range(0, 0.5)) = 0 } SubShader { Tags { "RenderType"="Opaque" } Cull off ZWrite On ZTest Lequal

     LOD 100

     Pass
     {
         CGPROGRAM
         #pragma vertex vert
         #pragma fragment frag

         #include "UnityCG.cginc"

         struct appdata
         {
             float4 vertex : POSITION;
         };

         struct v2f
         {
             float3 worldView : TEXCOORD1;
             float4 vertex : SV_POSITION;
         };

         v2f vert (appdata v)
         {
             v2f o;
             o.vertex = UnityObjectToClipPos(v.vertex);
             o.worldView = -WorldSpaceViewDir (v.vertex);
             return o;
         }
         sampler2D _MainTex;
         float _StretchDown;

         fixed4 frag (v2f i) : SV_Target
         {
             float3 dir = normalize(i.worldView);
             float2 uv = float2(0.5+atan2(dir.z, dir.x)/(2*UNITY_PI), _StretchDown+dir.y*(1-_StretchDown));
             uv.x*=3;
             fixed4 col = tex2D(_MainTex, uv);
             return col;
         }
         ENDCG
     }
 }

}`

I need to actually learn a bit more about using variables in shaders, my knowledge is truly awful to be honest!