0.8.19/20: Fantastic Global Update II

shader/lightRender.cs

@@ -1,30 +1,29 @@
 #define PI 3.14
 extern float xresolution;
-//从1D距离map采样
+//sample from 1D vis-depth map
 float samp(vec2 coord,float r,Image u_texture){
 	return step(r,Texel(u_texture,coord).r);
 }
 vec4 effect(vec4 color,Image texture,vec2 texture_coords,vec2 screen_coords){
-	//直角转极坐标，用于采样1D材质的y总是0
+	//cartesian to polar, y of 1D sample is always 0
 	vec2 norm=texture_coords.st*2.-1.;
 	float r=length(norm);
 	vec2 tc=vec2((atan(norm.y,norm.x)+PI)/(2.*PI),0.);
-	//根据离光源距离放大模糊系数，模拟影子淡出
-	float blur=(1./xresolution)*smoothstep(0.,1.,r);
 
-	//简易高斯模糊
-	float sum=
-		samp(vec2(tc.x-4.*blur,tc.y),r,texture)*.5
-		+samp(vec2(tc.x-3.*blur,tc.y),r,texture)*.9
-		+samp(vec2(tc.x-2.*blur,tc.y),r,texture)*.12
-		+samp(vec2(tc.x-1.*blur,tc.y),r,texture)*.15
+	//enlarge blur parameter by distance, light scattering simulation
+	float blur=(1./xresolution)*smoothstep(.3,1.,r);
 
-		+samp(tc,r,texture)*.16//The center tex coord,which gives us hard shadows.
-		+samp(vec2(tc.x+1.*blur,tc.y),r,texture)*.15
-		+samp(vec2(tc.x+2.*blur,tc.y),r,texture)*.12
-		+samp(vec2(tc.x+3.*blur,tc.y),r,texture)*.9
-		+samp(vec2(tc.x+4.*blur,tc.y),r,texture)*.5;
-	//sum值为亮度(0~1)
-	//乘上距离得到逐渐变淡的光线
-	return vec4(vec3(1.),sum*smoothstep(1.,.1,r));
+	//Simple Gaussian blur
+	float sum=//brightness(0~1)
+		samp(vec2(tc.x-3.*blur,tc.y),r,texture)*.1
+		+samp(vec2(tc.x-2.*blur,tc.y),r,texture)*.13
+		+samp(vec2(tc.x-1.*blur,tc.y),r,texture)*.17
+
+		+samp(tc,r,texture)*.2//The center tex coord,which gives us hard shadows.
+		+samp(vec2(tc.x+1.*blur,tc.y),r,texture)*.17
+		+samp(vec2(tc.x+2.*blur,tc.y),r,texture)*.13
+		+samp(vec2(tc.x+3.*blur,tc.y),r,texture)*.1;
+
+	//Multiply the distance to get a soft fading
+	return vec4(vec3(1.),sum*smoothstep(1.,0.,r));
 }