133 lines
4.0 KiB
GLSL
133 lines
4.0 KiB
GLSL
Shader "Unlit/StarFieldStars"
|
|
{
|
|
Properties
|
|
{
|
|
_Speed("Speed",Range(0.01,5.0)) = 0.1
|
|
_Scale("Scale",Range(1.0,50.0)) = 2.0
|
|
_StarISize("Star Inner Size",Range(0.001,0.1)) = 0.05
|
|
_StarCrossLines("Star Cross Lines Size",Range(1,1000)) = 1000
|
|
_GlowDistance("Glow Distance",Range(0.01,1.5)) = 1.0
|
|
_NumLayers("Number Of Layers",Range(1.0,20.0)) = 4.0
|
|
}
|
|
SubShader
|
|
{
|
|
Tags { "RenderType"="Opaque" }
|
|
LOD 100
|
|
|
|
Pass
|
|
{
|
|
CGPROGRAM
|
|
#pragma vertex vert
|
|
#pragma fragment frag
|
|
|
|
#include "UnityCG.cginc"
|
|
|
|
struct appdata
|
|
{
|
|
float4 vertex : POSITION;
|
|
float2 uv : TEXCOORD0;
|
|
};
|
|
|
|
struct v2f
|
|
{
|
|
float2 uv : TEXCOORD0;
|
|
float4 vertex : SV_POSITION;
|
|
};
|
|
|
|
fixed _Scale;
|
|
fixed _Speed;
|
|
fixed _StarISize;
|
|
fixed _StarCrossLines;
|
|
fixed _GlowDistance;
|
|
fixed _NumLayers;
|
|
|
|
v2f vert (appdata v)
|
|
{
|
|
v2f o;
|
|
o.vertex = UnityObjectToClipPos(v.vertex);
|
|
o.uv = v.uv;
|
|
return o;
|
|
}
|
|
|
|
fixed2x2 Rot(fixed a)
|
|
{
|
|
fixed s = sin(a) , c = cos(a);
|
|
return fixed2x2(c, -s ,s ,c);
|
|
}
|
|
|
|
fixed Star(fixed2 uv, fixed flare)
|
|
{
|
|
fixed d = length(uv); // distance to center
|
|
fixed m = _StarISize/d;//smoothstep(0.1,0.05, d);
|
|
|
|
fixed rays = max(0.0, 1.0-abs(uv.x*uv.y*_StarCrossLines));
|
|
m += rays * flare;
|
|
uv = mul(uv, Rot(3.1415/4.0)); // rot by 45 degrees
|
|
rays = max(0.0, 1.0-abs(uv.x*uv.y*_StarCrossLines));
|
|
m += rays * 0.3 * flare;
|
|
|
|
m *= smoothstep(_GlowDistance,0.2, d); // fade star brightness from distance
|
|
return m;
|
|
}
|
|
|
|
fixed Hash21( fixed2 p)
|
|
{
|
|
p = frac( p * fixed2(123.34, 456.21));
|
|
p += dot(p, p+45.32);
|
|
return frac(p.x * p.y);
|
|
}
|
|
|
|
fixed3 StarLayer(fixed2 uv)
|
|
{
|
|
fixed3 col = 0;
|
|
|
|
fixed2 gv = frac(uv) - 0.5; // grid uv
|
|
fixed2 id = floor(uv);
|
|
|
|
for(int y= -1; y <= 1; y++)
|
|
{
|
|
for(int x = -1; x <= 1; x++)
|
|
{
|
|
fixed2 offs = fixed2(x,y);
|
|
|
|
fixed n = Hash21(id + offs); // random between 0 and 1
|
|
fixed size = frac(n * 345.32);
|
|
|
|
fixed star = Star(gv - offs - fixed2(n, frac(n * 34.0)) + 0.5, smoothstep(0.8,0.9,size));
|
|
fixed3 color = sin(fixed3(0.2,0.3,0.9) * frac(n*2345.2)*123.2) * 0.5 + 0.5;
|
|
color *= fixed3(1,0.5,1.+size);
|
|
|
|
star *= sin(_Time.y *3. + n * 6.2831) * 0.5 + 1.0; // twinkle effect
|
|
col += star * size * color;
|
|
}
|
|
}
|
|
|
|
return col;
|
|
}
|
|
|
|
fixed4 frag (v2f i) : SV_Target
|
|
{
|
|
fixed2 uv = (i.uv - 0.5) * _Scale;
|
|
|
|
fixed3 col = 0;
|
|
fixed time = _Time.y * _Speed;
|
|
|
|
uv = mul(uv , Rot(time));
|
|
for(fixed i=0; i <1.0; i+=1.0/_NumLayers)
|
|
{
|
|
fixed depth = frac(i+time);
|
|
|
|
fixed scale = lerp(20.,0.5, depth);
|
|
fixed fade = depth * smoothstep(1.0,0.9, depth);
|
|
col += StarLayer(uv * scale + i*423.25) * fade;
|
|
}
|
|
// for debuging
|
|
//if(gv.x > 0.48 || gv.y > 0.48) col.r = 1.0;
|
|
|
|
return fixed4(col,1.0);
|
|
}
|
|
ENDCG
|
|
}
|
|
}
|
|
}
|