Properties{
// normal map texture on the material,
// default to dummy "flat surface" normalmap
_BumpMap("Normal Map", 2D) = "bump" {}
}
SubShader
{
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
struct v2f {
float3 worldPos : TEXCOORD0;
// these three vectors will hold a 3x3 rotation matrix
// that transforms from tangent to world space
half3 tspace0 : TEXCOORD1; // tangent.x, bitangent.x, normal.x
half3 tspace1 : TEXCOORD2; // tangent.y, bitangent.y, normal.y
half3 tspace2 : TEXCOORD3; // tangent.z, bitangent.z, normal.z
// texture coordinate for the normal map
float2 uv : TEXCOORD4;
float4 pos : SV_POSITION;
};
// vertex shader now also needs a per-vertex tangent vector.
// in Unity tangents are 4D vectors, with the .w component used to
// indicate direction of the bitangent vector.
// we also need the texture coordinate.
v2f vert(float4 vertex : POSITION, float3 normal : NORMAL, float4 tangent : TANGENT, float2 uv : TEXCOORD0)
{
v2f o;
o.pos = UnityObjectToClipPos(vertex);
o.worldPos = mul(_Object2World, vertex).xyz;
half3 wNormal = UnityObjectToWorldNormal(normal);
half3 wTangent = UnityObjectToWorldDir(tangent.xyz);
// compute bitangent from cross product of normal and tangent
half tangentSign = tangent.w * unity_WorldTransformParams.w;
half3 wBitangent = cross(wNormal, wTangent) * tangentSign;
// output the tangent space matrix
o.tspace0 = half3(wTangent.x, wBitangent.x, wNormal.x);
o.tspace1 = half3(wTangent.y, wBitangent.y, wNormal.y);
o.tspace2 = half3(wTangent.z, wBitangent.z, wNormal.z);
o.uv = uv;
return o;
}
// normal map texture from shader properties
sampler2D _BumpMap;
fixed4 frag(v2f i) : SV_Target
{
// sample the normal map, and decode from the Unity encoding
half3 tnormal = UnpackNormal(tex2D(_BumpMap, i.uv));
// transform normal from tangent to world space
half3 worldNormal;
worldNormal.x = dot(i.tspace0, tnormal);
worldNormal.y = dot(i.tspace1, tnormal);
worldNormal.z = dot(i.tspace2, tnormal);
// rest the same as in previous shader
half3 worldViewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));
half3 worldRefl = reflect(-worldViewDir, worldNormal);
half4 skyData = UNITY_SAMPLE_TEXCUBE(unity_SpecCube0, worldRefl);
half3 skyColor = DecodeHDR(skyData, unity_SpecCube0_HDR);
fixed4 c = 0;
c.rgb = skyColor;
return c;
}
ENDCG
}
}
}
