2020-11-28 16:54:41 +02:00

139 lines
5.0 KiB
GLSL

Shader "Unlit/GrassShaderLearn"
{
Properties {
_MainTex ("Texture", 2D) = "white" {}
_Color ("Color", COlor) = (1,1,1,1)
_BottomCol ("Bottom", COlor) = (1,1,1,1)
_TopCol ("Top", COlor) = (1,1,1,1)
_BendRotationRandom("Bend Rotation Random", Range(0, 1)) = 0.2
_BladeWidth("Blade Width", Float) = 0.05
_BladeWidthRandom("Blade Width Random", Float) = 0.02
_BladeHeight("Blade Height", Float) = 0.5
_BladeHeightRandom("Blade Height Random", Float) = 0.3
_TessellationUniform("Tessellation Uniform", Range(1, 64)) = 1
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma geometry geo
//#pragma hull hull
//#pragma domain domain
// make fog work
#pragma multi_compile_fog
#include "UnityCG.cginc"
//#include "Shaders/CustomTessellation.cginc"
struct appdata
{
float2 uv : TEXCOORD0;
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 tangent : TANGENT;
};
struct v2f
{
float2 uv : TEXCOORD0;
//UNITY_FOG_COORDS(1)
float4 vertex : SV_POSITION;
float3 normal : NORMAL;
float4 tangent : TANGENT;
};
struct geometryOutput {
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
};
geometryOutput VertexOutput(float3 pos, float2 uv){
geometryOutput o;
o.pos = UnityObjectToClipPos(pos);
o.uv = uv;
return o;
}
float rand(float3 co){
return frac(sin(dot(co.xyz, float3(12.9898, 78.233, 53.539))) * 43758.5453);
}
float3x3 AngleAxis3x3(float angle, float3 axis){
float c, s;
sincos(angle, s, c);
float t = 1 - c;
float x = axis.x;
float y = axis.y;
float z = axis.z;
return float3x3(
t * x * x + c, t * x * y - s * z, t * x * z + s * y,
t * x * y + s * z, t * y * y + c, t * y * z - s * x,
t * x * z - s * y, t * y * z + s * x, t * z * z + c
);
}
sampler2D _MainTex;
float4 _MainTex_ST;
fixed4 _Color, _BottomCol, _TopCol;
float _BendRotationRandom;
float _BladeHeight;
float _BladeHeightRandom;
float _BladeWidth;
float _BladeWidthRandom;
v2f vert (appdata v) {
v2f o;
o.vertex = v.vertex;//UnityObjectToClipPos(v.vertex);
o.uv = TRANSFORM_TEX(v.uv, _MainTex);
o.normal = v.normal;
o.tangent = v.tangent;
//UNITY_TRANSFER_FOG(o,o.vertex);
return o;
}
[maxvertexcount(3)]
void geo(triangle v2f IN[3] : SV_POSITION, inout TriangleStream<geometryOutput> triStream) {
float3 pos = IN[0].vertex;
float3 vNormal = IN[0].normal;
float4 vTangent = IN[0].tangent;
float3 vBinormal = cross (vNormal,vTangent)*vTangent.w;
float height = (rand(pos.zyx) * 2 - 1) * _BladeHeightRandom + _BladeHeight;
float width = (rand(pos.xzy) * 2 - 1) * _BladeWidthRandom + _BladeWidth;
float3x3 tangentToLocal = float3x3(
vTangent.x, vBinormal.x, vNormal.x,
vTangent.y, vBinormal.y, vNormal.y,
vTangent.z, vBinormal.z, vNormal.z
);
float3x3 facingRotationMatrix = AngleAxis3x3(rand(pos) * UNITY_TWO_PI, float3(0, 0, 1));
float3x3 bendRotationMatrix = AngleAxis3x3(rand(pos.zzx) * _BendRotationRandom * UNITY_PI * 0.5, float3(-1, 0, 0));
float3x3 transformationMatrix = mul(mul(tangentToLocal, facingRotationMatrix),bendRotationMatrix);
triStream.Append(VertexOutput(pos + mul(transformationMatrix, float3(width, 0, 0 )), float2(0 ,0) ));
triStream.Append(VertexOutput(pos + mul(transformationMatrix, float3(-width, 0, 0)), float2(1 ,0) ));
triStream.Append(VertexOutput(pos + mul(transformationMatrix, float3(height, 0, 1 )), float2(0.5,1) ));
}
fixed4 frag (geometryOutput i) : SV_Target {
// sample the texture
fixed4 col = tex2D(_MainTex, i.uv) * _Color;
// apply fog
//UNITY_APPLY_FOG(i.fogCoord, col);
return lerp(_BottomCol, _TopCol, i.uv.y) * _Color;
}
ENDCG
}
}
}