@@ -7,67 +7,84 @@ $define shader fragment
77
88$include ../functions/ common.glsl
99$include ../functions/ hash.glsl
10- $include ssaoParams.glsl
10+ // $include ssaoParams.glsl
11+
12+
13+ layout (std140, binding = CAGE_SHADER_UNIBLOCK_CUSTOMDATA) uniform Ssao
14+ {
15+ mat4 proj;
16+ mat4 projInv;
17+ vec4 params; // strength, bias, power, radius
18+ ivec4 iparams; // sampleCount, hashSeed
19+ };
20+
1121
1222layout (std140, binding = 3 ) uniform SsaoPoints
1323{
24+ // unit sphere samples; .w is [0,1] random scalar
1425 vec4 pointsOnSphere[256 ];
1526};
1627
17- layout (binding = 0 ) uniform sampler2D texDepth;
28+ layout (binding = 0 ) uniform sampler2D texDepth; // NDC depth [0,1]
1829
1930out float outAo;
2031
21- vec3 reconstructNormal(vec3 position)
22- {
23- return normalize (cross (dFdx (position), dFdy (position)));
24- }
25-
26- vec3 s2w(vec2 p, float d)
32+ // inputs in NDC [-1,1]
33+ vec3 ndcToView(vec2 p, float d)
2734{
2835 vec4 p4 = vec4 (p, d, 1 );
2936 p4 = projInv * p4;
3037 return p4.xyz / p4.w;
3138}
3239
40+ // all view-space
41+ vec3 reconstructNormal(vec3 position)
42+ {
43+ return normalize (cross (dFdx (position), dFdy (position)));
44+ }
45+
3346void main()
3447{
3548 vec2 resolution = vec2 (textureSize(texDepth, 0 ));
36- vec2 myUv = gl_FragCoord .xy / resolution;
37- float myDepth = textureLod(texDepth, myUv, 0 ).x * 2.0 - 1.0 ;
49+ vec2 myUv = gl_FragCoord .xy / resolution; // screen-space [0,1]
50+ float myDepth = textureLod(texDepth, myUv, 0 ).x * 2 - 1 ; // NDC depth [-1,1]
3851 if (myDepth > 0.999 )
3952 { // no occlusion on skybox
4053 outAo = 0 ;
4154 return ;
4255 }
43- vec3 myPos = s2w (myUv, myDepth);
44- vec3 myNormal = reconstructNormal(myPos);
56+ vec3 myPos = ndcToView (myUv * 2 - 1 , myDepth); // view-space position
57+ vec3 myNormal = reconstructNormal(myPos); // view-space normal
4558
4659 // sampling
47- int n = int ( hash(uint (gl_FragCoord .x) ^ hash(uint (gl_FragCoord .y)) ^ uint (iparams[1 ])));
60+ uint n = hash(uint (gl_FragCoord .x) ^ hash(uint (gl_FragCoord .y)) ^ uint (iparams[1 ])); // per-pixel seed
4861 float ssaoRadius = params[3 ];
49- float occ = 0.0 ;
50- float total = 0.0 ;
62+ float occ = 0 ;
63+ float total = 0 ;
5164 for (int i = 0 ; i < iparams[0 ]; i++ )
5265 {
53- vec3 dir = pointsOnSphere[hash(uint (n * 17 + i)) % 256 ].xyz;
54- float d = dot (myNormal, dir);
66+ // view-space ray direction
67+ vec3 rayDir = pointsOnSphere[hash(uint (n * 17 + i)) % 256 ].xyz;
68+ float d = dot (myNormal, rayDir);
5569 if (abs (d) < 0.1 )
5670 continue ; // the direction is close to the surface and susceptible to noise
57- dir = sign (d) * dir; // move the direction into front hemisphere
58- float r = (sqr(pointsOnSphere[hash(uint (n * 13 + i)) % 256 ].w) * 0.9 + 0.1 ) * ssaoRadius;
59- vec3 sw = myPos + dir * r;
60- vec4 s4 = proj * vec4 (sw, 1.0 );
61- vec3 ss = s4.xyz / s4.w;
62- float sampleDepth = textureLod(texDepth, ss.xy, 0 ).x * 2.0 - 1.0 ;
63- if (sampleDepth < ss.z)
71+ rayDir = sign (d) * rayDir; // move the direction into front hemisphere
72+ rayDir *= (sqr(pointsOnSphere[hash(uint (n * 13 + i)) % 256 ].w) * 0.9 + 0.1 ) * ssaoRadius;
73+
74+ vec3 rayPos = myPos + rayDir; // view-space ray position
75+ vec4 r4 = proj * vec4 (rayPos, 1 ); // clip space
76+ vec3 rayNdc = r4.xyz / r4.w; // NDC [-1,1]
77+
78+ float sampleDepth = textureLod(texDepth, rayNdc.xy * 0.5 + 0.5 , 0 ).x * 2 - 1 ; // NDC depth [-1,1]
79+ if (sampleDepth < rayNdc.z)
6480 {
65- vec3 otherPos = s2w(ss .xy, sampleDepth);
66- float diff = length (sw - otherPos );
67- occ += smoothstep (1.0 , 0. 0/ ssaoRadius);
81+ vec3 samplePos = ndcToView(rayNdc .xy, sampleDepth); // view-space sample position
82+ float diff = length (rayPos - samplePos );
83+ occ += smoothstep (1 , 0 , diff / ssaoRadius);
6884 }
69- total += 1.0 ;
85+ total += 1 ;
7086 }
87+
7188 if (total > 0 )
7289 outAo = occ / total;
7390 else
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