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@sergiobd
Created November 10, 2018 17:57
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Unity skybox 6-sided with arbitrary rotation axis
// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)
// Edited from Unity built-in, copied rotation function from here: http://www.neilmendoza.com/glsl-rotation-about-an-arbitrary-axis/
Shader "Skybox/6 Sided - Arbitrary Rotation" {
Properties {
_Tint ("Tint Color", Color) = (.5, .5, .5, .5)
[Gamma] _Exposure ("Exposure", Range(0, 8)) = 1.0
_Rotation ("Rotation", Range(0, 360)) = 0
_RotationAxis("Rotation axis", Vector) = (0, 1, 0)
[NoScaleOffset] _FrontTex ("Front [+Z] (HDR)", 2D) = "grey" {}
[NoScaleOffset] _BackTex ("Back [-Z] (HDR)", 2D) = "grey" {}
[NoScaleOffset] _LeftTex ("Left [+X] (HDR)", 2D) = "grey" {}
[NoScaleOffset] _RightTex ("Right [-X] (HDR)", 2D) = "grey" {}
[NoScaleOffset] _UpTex ("Up [+Y] (HDR)", 2D) = "grey" {}
[NoScaleOffset] _DownTex ("Down [-Y] (HDR)", 2D) = "grey" {}
}
SubShader {
Tags { "Queue"="Background" "RenderType"="Background" "PreviewType"="Skybox" }
Cull Off ZWrite Off
CGINCLUDE
#include "UnityCG.cginc"
half4 _Tint;
half _Exposure;
float _Rotation;
float3 _RotationAxis;
float3 RotateAroundYInDegrees (float3 vertex, float degrees)
{
float alpha = degrees * UNITY_PI / 180.0;
float sina, cosa;
sincos(alpha, sina, cosa);
float2x2 m = float2x2(cosa, -sina, sina, cosa);
return float3(mul(m, vertex.xz), vertex.y).xzy;
}
float4x4 rotationMatrix(float3 axis, float angle)
{
axis = normalize(axis);
float s = sin(angle);
float c = cos(angle);
float oc = 1.0 - c;
return float4x4(oc * axis.x * axis.x + c, oc * axis.x * axis.y - axis.z * s, oc * axis.z * axis.x + axis.y * s, 0.0,
oc * axis.x * axis.y + axis.z * s, oc * axis.y * axis.y + c, oc * axis.y * axis.z - axis.x * s, 0.0,
oc * axis.z * axis.x - axis.y * s, oc * axis.y * axis.z + axis.x * s, oc * axis.z * axis.z + c, 0.0,
0.0, 0.0, 0.0, 1.0);
}
struct appdata_t {
float4 vertex : POSITION;
float2 texcoord : TEXCOORD0;
UNITY_VERTEX_INPUT_INSTANCE_ID
};
struct v2f {
float4 vertex : SV_POSITION;
float2 texcoord : TEXCOORD0;
UNITY_VERTEX_OUTPUT_STEREO
};
v2f vert (appdata_t v)
{
v2f o;
UNITY_SETUP_INSTANCE_ID(v);
UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
//float3 rotated = RotateAroundYInDegrees(v.vertex, _Rotation);
float3 rotated = mul( rotationMatrix( normalize(_RotationAxis.xyz), _Rotation * UNITY_PI / 180.0), v.vertex).xyz;
o.vertex = UnityObjectToClipPos(rotated);
o.texcoord = v.texcoord;
return o;
}
half4 skybox_frag (v2f i, sampler2D smp, half4 smpDecode)
{
half4 tex = tex2D (smp, i.texcoord);
half3 c = DecodeHDR (tex, smpDecode);
c = c * _Tint.rgb * unity_ColorSpaceDouble.rgb;
c *= _Exposure;
return half4(c, 1);
}
ENDCG
Pass {
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
sampler2D _FrontTex;
half4 _FrontTex_HDR;
half4 frag (v2f i) : SV_Target { return skybox_frag(i,_FrontTex, _FrontTex_HDR); }
ENDCG
}
Pass{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
sampler2D _BackTex;
half4 _BackTex_HDR;
half4 frag (v2f i) : SV_Target { return skybox_frag(i,_BackTex, _BackTex_HDR); }
ENDCG
}
Pass{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
sampler2D _LeftTex;
half4 _LeftTex_HDR;
half4 frag (v2f i) : SV_Target { return skybox_frag(i,_LeftTex, _LeftTex_HDR); }
ENDCG
}
Pass{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
sampler2D _RightTex;
half4 _RightTex_HDR;
half4 frag (v2f i) : SV_Target { return skybox_frag(i,_RightTex, _RightTex_HDR); }
ENDCG
}
Pass{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
sampler2D _UpTex;
half4 _UpTex_HDR;
half4 frag (v2f i) : SV_Target { return skybox_frag(i,_UpTex, _UpTex_HDR); }
ENDCG
}
Pass{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma target 2.0
sampler2D _DownTex;
half4 _DownTex_HDR;
half4 frag (v2f i) : SV_Target { return skybox_frag(i,_DownTex, _DownTex_HDR); }
ENDCG
}
}
}
@katerynak
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Much appreciated! ☺

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