phoenix-firestorm/indra/newview/app_settings/shaders/class3/deferred/reflectionProbeF.glsl

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22 KiB
GLSL

/**
* @file class3/deferred/reflectionProbeF.glsl
*
* $LicenseInfo:firstyear=2022&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2022, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#define FLT_MAX 3.402823466e+38
#if defined(SSR)
float tapScreenSpaceReflection(int totalSamples, vec2 tc, vec3 viewPos, vec3 n, inout vec4 collectedColor, sampler2D source);
#endif
#define REFMAP_COUNT 256
#define REF_SAMPLE_COUNT 64 //maximum number of samples to consider
uniform samplerCubeArray reflectionProbes;
uniform samplerCubeArray irradianceProbes;
uniform sampler2D sceneMap;
uniform int cube_snapshot;
uniform float max_probe_lod;
layout (std140) uniform ReflectionProbes
{
// list of OBBs for user override probes
// box is a set of 3 planes outward facing planes and the depth of the box along that plane
// for each box refBox[i]...
/// box[0..2] - plane 0 .. 2 in [A,B,C,D] notation
// box[3][0..2] - plane thickness
mat4 refBox[REFMAP_COUNT];
// list of bounding spheres for reflection probes sorted by distance to camera (closest first)
vec4 refSphere[REFMAP_COUNT];
// extra parameters (currently only .x used for probe ambiance)
vec4 refParams[REFMAP_COUNT];
// index of cube map in reflectionProbes for a corresponding reflection probe
// e.g. cube map channel of refSphere[2] is stored in refIndex[2]
// refIndex.x - cubemap channel in reflectionProbes
// refIndex.y - index in refNeighbor of neighbor list (index is ivec4 index, not int index)
// refIndex.z - number of neighbors
// refIndex.w - priority, if negative, this probe has a box influence
ivec4 refIndex[REFMAP_COUNT];
// neighbor list data (refSphere indices, not cubemap array layer)
ivec4 refNeighbor[1024];
// number of reflection probes present in refSphere
int refmapCount;
};
// Inputs
uniform mat3 env_mat;
// list of probeIndexes shader will actually use after "getRefIndex" is called
// (stores refIndex/refSphere indices, NOT rerflectionProbes layer)
int probeIndex[REF_SAMPLE_COUNT];
// number of probes stored in probeIndex
int probeInfluences = 0;
bool isAbove(vec3 pos, vec4 plane)
{
return (dot(plane.xyz, pos) + plane.w) > 0;
}
int max_priority = 0;
// return true if probe at index i influences position pos
bool shouldSampleProbe(int i, vec3 pos)
{
if (refIndex[i].w < 0)
{
vec4 v = refBox[i] * vec4(pos, 1.0);
if (abs(v.x) > 1 ||
abs(v.y) > 1 ||
abs(v.z) > 1)
{
return false;
}
max_priority = max(max_priority, -refIndex[i].w);
}
else
{
if (refSphere[i].w > 0.0) // zero is special indicator to always sample this probe
{
vec3 delta = pos.xyz - refSphere[i].xyz;
float d = dot(delta, delta);
float r2 = refSphere[i].w;
r2 *= r2;
if (d > r2)
{ //outside bounding sphere
return false;
}
}
max_priority = max(max_priority, refIndex[i].w);
}
return true;
}
// call before sampleRef
// populate "probeIndex" with N probe indices that influence pos where N is REF_SAMPLE_COUNT
// overall algorithm --
void preProbeSample(vec3 pos)
{
// TODO: make some sort of structure that reduces the number of distance checks
for (int i = 1; i < refmapCount; ++i)
{
// found an influencing probe
if (shouldSampleProbe(i, pos))
{
probeIndex[probeInfluences] = i;
++probeInfluences;
int neighborIdx = refIndex[i].y;
if (neighborIdx != -1)
{
int neighborCount = min(refIndex[i].z, REF_SAMPLE_COUNT-1);
int count = 0;
while (count < neighborCount)
{
// check up to REF_SAMPLE_COUNT-1 neighbors (neighborIdx is ivec4 index)
int idx = refNeighbor[neighborIdx].x;
if (shouldSampleProbe(idx, pos))
{
probeIndex[probeInfluences++] = idx;
if (probeInfluences == REF_SAMPLE_COUNT)
{
break;
}
}
count++;
if (count == neighborCount)
{
break;
}
idx = refNeighbor[neighborIdx].y;
if (shouldSampleProbe(idx, pos))
{
probeIndex[probeInfluences++] = idx;
if (probeInfluences == REF_SAMPLE_COUNT)
{
break;
}
}
count++;
if (count == neighborCount)
{
break;
}
idx = refNeighbor[neighborIdx].z;
if (shouldSampleProbe(idx, pos))
{
probeIndex[probeInfluences++] = idx;
if (probeInfluences == REF_SAMPLE_COUNT)
{
break;
}
}
count++;
if (count == neighborCount)
{
break;
}
idx = refNeighbor[neighborIdx].w;
if (shouldSampleProbe(idx, pos))
{
probeIndex[probeInfluences++] = idx;
if (probeInfluences == REF_SAMPLE_COUNT)
{
break;
}
}
count++;
if (count == neighborCount)
{
break;
}
++neighborIdx;
}
break;
}
}
}
if (max_priority <= 1)
{ // probe at index 0 is a special probe for smoothing out automatic probes
probeIndex[probeInfluences++] = 0;
}
}
// from https://www.scratchapixel.com/lessons/3d-basic-rendering/minimal-ray-tracer-rendering-simple-shapes/ray-sphere-intersection
// original reference implementation:
/*
bool intersect(const Ray &ray) const
{
float t0, t1; // solutions for t if the ray intersects
#if 0
// geometric solution
Vec3f L = center - orig;
float tca = L.dotProduct(dir);
// if (tca < 0) return false;
float d2 = L.dotProduct(L) - tca * tca;
if (d2 > radius2) return false;
float thc = sqrt(radius2 - d2);
t0 = tca - thc;
t1 = tca + thc;
#else
// analytic solution
Vec3f L = orig - center;
float a = dir.dotProduct(dir);
float b = 2 * dir.dotProduct(L);
float c = L.dotProduct(L) - radius2;
if (!solveQuadratic(a, b, c, t0, t1)) return false;
#endif
if (t0 > t1) std::swap(t0, t1);
if (t0 < 0) {
t0 = t1; // if t0 is negative, let's use t1 instead
if (t0 < 0) return false; // both t0 and t1 are negative
}
t = t0;
return true;
} */
// adapted -- assume that origin is inside sphere, return intersection of ray with edge of sphere
vec3 sphereIntersect(vec3 origin, vec3 dir, vec3 center, float radius2)
{
float t0, t1; // solutions for t if the ray intersects
vec3 L = center - origin;
float tca = dot(L,dir);
float d2 = dot(L,L) - tca * tca;
float thc = sqrt(radius2 - d2);
t0 = tca - thc;
t1 = tca + thc;
vec3 v = origin + dir * t1;
return v;
}
void swap(inout float a, inout float b)
{
float t = a;
a = b;
b = a;
}
// debug implementation, make no assumptions about origin
void sphereIntersectDebug(vec3 origin, vec3 dir, vec3 center, float radius2, float depth, inout vec4 col)
{
float t[2]; // solutions for t if the ray intersects
// geometric solution
vec3 L = center - origin;
float tca = dot(L, dir);
// if (tca < 0) return false;
float d2 = dot(L, L) - tca * tca;
if (d2 > radius2) return;
float thc = sqrt(radius2 - d2);
t[0] = tca - thc;
t[1] = tca + thc;
for (int i = 0; i < 2; ++i)
{
if (t[i] > 0)
{
if (t[i] > depth)
{
float w = 0.125/((t[i]-depth)*0.125 + 1.0);
col += vec4(0, 0, w, w)*(1.0-min(col.a, 1.0));
}
else
{
float w = 0.25;
col += vec4(w,w,0,w)*(1.0-min(col.a, 1.0));
}
}
}
}
// from https://seblagarde.wordpress.com/2012/09/29/image-based-lighting-approaches-and-parallax-corrected-cubemap/
/*
vec3 DirectionWS = normalize(PositionWS - CameraWS);
vec3 ReflDirectionWS = reflect(DirectionWS, NormalWS);
// Intersection with OBB convertto unit box space
// Transform in local unit parallax cube space (scaled and rotated)
vec3 RayLS = MulMatrix( float(3x3)WorldToLocal, ReflDirectionWS);
vec3 PositionLS = MulMatrix( WorldToLocal, PositionWS);
vec3 Unitary = vec3(1.0f, 1.0f, 1.0f);
vec3 FirstPlaneIntersect = (Unitary - PositionLS) / RayLS;
vec3 SecondPlaneIntersect = (-Unitary - PositionLS) / RayLS;
vec3 FurthestPlane = max(FirstPlaneIntersect, SecondPlaneIntersect);
float Distance = min(FurthestPlane.x, min(FurthestPlane.y, FurthestPlane.z));
// Use Distance in WS directly to recover intersection
vec3 IntersectPositionWS = PositionWS + ReflDirectionWS * Distance;
vec3 ReflDirectionWS = IntersectPositionWS - CubemapPositionWS;
return texCUBE(envMap, ReflDirectionWS);
*/
// get point of intersection with given probe's box influence volume
// origin - ray origin in clip space
// dir - ray direction in clip space
// i - probe index in refBox/refSphere
// d - distance to nearest wall in clip space
vec3 boxIntersect(vec3 origin, vec3 dir, int i, out float d)
{
// Intersection with OBB convertto unit box space
// Transform in local unit parallax cube space (scaled and rotated)
mat4 clipToLocal = refBox[i];
vec3 RayLS = mat3(clipToLocal) * dir;
vec3 PositionLS = (clipToLocal * vec4(origin, 1.0)).xyz;
d = 1.0-max(max(abs(PositionLS.x), abs(PositionLS.y)), abs(PositionLS.z));
vec3 Unitary = vec3(1.0f, 1.0f, 1.0f);
vec3 FirstPlaneIntersect = (Unitary - PositionLS) / RayLS;
vec3 SecondPlaneIntersect = (-Unitary - PositionLS) / RayLS;
vec3 FurthestPlane = max(FirstPlaneIntersect, SecondPlaneIntersect);
float Distance = min(FurthestPlane.x, min(FurthestPlane.y, FurthestPlane.z));
// Use Distance in CS directly to recover intersection
vec3 IntersectPositionCS = origin + dir * Distance;
return IntersectPositionCS;
}
void debugBoxCol(vec3 ro, vec3 rd, float t, vec3 p, inout vec4 col)
{
vec3 v = ro + rd * t;
v -= ro;
vec3 pos = p - ro;
bool behind = dot(v,v) > dot(pos,pos);
float w = 0.25;
if (behind)
{
w *= 0.5;
w /= (length(v)-length(pos))*0.5+1.0;
col += vec4(0,0,w,w)*(1.0-min(col.a, 1.0));
}
else
{
col += vec4(w,w,0,w)*(1.0-min(col.a, 1.0));
}
}
// cribbed from https://iquilezles.org/articles/intersectors/
// axis aligned box centered at the origin, with size boxSize
void boxIntersectionDebug( in vec3 ro, in vec3 p, vec3 boxSize, inout vec4 col)
{
vec3 rd = normalize(p-ro);
vec3 m = 1.0/rd; // can precompute if traversing a set of aligned boxes
vec3 n = m*ro; // can precompute if traversing a set of aligned boxes
vec3 k = abs(m)*boxSize;
vec3 t1 = -n - k;
vec3 t2 = -n + k;
float tN = max( max( t1.x, t1.y ), t1.z );
float tF = min( min( t2.x, t2.y ), t2.z );
if( tN>tF || tF<0.0) return ; // no intersection
float t = tN < 0 ? tF : tN;
debugBoxCol(ro, rd, t, p, col);
if (tN > 0) // eye is outside box, check backside, too
{
debugBoxCol(ro, rd, tF, p, col);
}
}
void boxIntersectDebug(vec3 origin, vec3 pos, int i, inout vec4 col)
{
mat4 clipToLocal = refBox[i];
// transform into unit cube space
origin = (clipToLocal * vec4(origin, 1.0)).xyz;
pos = (clipToLocal * vec4(pos, 1.0)).xyz;
boxIntersectionDebug(origin, pos, vec3(1), col);
}
// get the weight of a sphere probe
// pos - position to be weighted
// dir - normal to be weighted
// origin - center of sphere probe
// r - radius of probe influence volume
// min_da - minimum angular attenuation coefficient
float sphereWeight(vec3 pos, vec3 dir, vec3 origin, float r, float min_da)
{
float r1 = r * 0.5; // 50% of radius (outer sphere to start interpolating down)
vec3 delta = pos.xyz - origin;
float d2 = max(length(delta), 0.001);
float r2 = r1; //r1 * r1;
//float atten = 1.0 - max(d2 - r2, 0.0) / max((rr - r2), 0.001);
float atten = 1.0 - max(d2 - r2, 0.0) / max((r - r2), 0.001);
atten *= max(dot(normalize(-delta), dir), min_da);
float w = 1.0 / d2;
w *= atten;
return w;
}
// Tap a reflection probe
// pos - position of pixel
// dir - pixel normal
// vi - return value of intersection point with influence volume
// wi - return value of approximate world space position of sampled pixel
// lod - which mip to bias towards (lower is higher res, sharper reflections)
// c - center of probe
// r2 - radius of probe squared
// i - index of probe
vec3 tapRefMap(vec3 pos, vec3 dir, out float w, out vec3 vi, out vec3 wi, float lod, vec3 c, int i)
{
//lod = max(lod, 1);
// parallax adjustment
vec3 v;
if (refIndex[i].w < 0)
{
float d = 0;
v = boxIntersect(pos, dir, i, d);
w = max(d, 0.001);
}
else
{
float r = refSphere[i].w; // radius of sphere volume
float rr = r * r; // radius squared
v = sphereIntersect(pos, dir, c,
refIndex[i].w <= 1 ? 4096.0*4096.0 : // <== effectively disable parallax correction for automatically placed probes to keep from bombing the world with obvious spheres
rr);
w = sphereWeight(pos, dir, refSphere[i].xyz, r, 0.25);
}
vi = v;
v -= c;
vec3 d = normalize(v);
v = env_mat * v;
vec4 ret = textureLod(reflectionProbes, vec4(v.xyz, refIndex[i].x), lod);
wi = d * ret.a * 256.0+c;
return ret.rgb;
}
// Tap an irradiance map
// pos - position of pixel
// dir - pixel normal
// c - center of probe
// r2 - radius of probe squared
// i - index of probe
vec3 tapIrradianceMap(vec3 pos, vec3 dir, out float w, vec3 c, int i)
{
// parallax adjustment
vec3 v;
if (refIndex[i].w < 0)
{
float d = 0.0;
v = boxIntersect(pos, dir, i, d);
w = max(d, 0.001);
}
else
{
float r = refSphere[i].w; // radius of sphere volume
float p = float(abs(refIndex[i].w)); // priority
float rr = r * r; // radius squred
v = sphereIntersect(pos, dir, c,
refIndex[i].w <= 1 ? 4096.0*4096.0 : // <== effectively disable parallax correction for automatically placed probes to keep from bombing the world with obvious spheres
rr);
w = sphereWeight(pos, dir, refSphere[i].xyz, r, 0.001);
}
v -= c;
v = env_mat * v;
{
return textureLod(irradianceProbes, vec4(v.xyz, refIndex[i].x), 0).rgb * refParams[i].x;
}
}
vec3 sampleProbes(vec3 pos, vec3 dir, float lod, bool errorCorrect)
{
float wsum = 0.0;
vec3 col = vec3(0,0,0);
float vd2 = dot(pos,pos); // view distance squared
for (int idx = 0; idx < probeInfluences; ++idx)
{
int i = probeIndex[idx];
if (abs(refIndex[i].w) < max_priority)
{
continue;
}
float w;
vec3 vi, wi;
vec3 refcol;
{
if (errorCorrect && refIndex[i].w >= 0)
{ // error correction is on and this probe is a sphere
//take a sample to get depth value, then error correct
refcol = tapRefMap(pos, dir, w, vi, wi, abs(lod + 2), refSphere[i].xyz, i);
//adjust lookup by distance result
float d = length(vi - wi);
vi += dir * d;
vi -= refSphere[i].xyz;
vi = env_mat * vi;
refcol = textureLod(reflectionProbes, vec4(vi, refIndex[i].x), lod).rgb;
// weight by vector correctness
vec3 pi = normalize(wi - pos);
w *= max(dot(pi, dir), 0.1);
//w = pow(w, 32.0);
}
else
{
refcol = tapRefMap(pos, dir, w, vi, wi, lod, refSphere[i].xyz, i);
}
col += refcol.rgb*w;
wsum += w;
}
}
if (wsum > 0.0)
{
col *= 1.0/wsum;
}
return col;
}
vec3 sampleProbeAmbient(vec3 pos, vec3 dir)
{
// modified copy/paste of sampleProbes follows, will likely diverge from sampleProbes further
// as irradiance map mixing is tuned independently of radiance map mixing
float wsum = 0.0;
vec3 col = vec3(0,0,0);
float vd2 = dot(pos,pos); // view distance squared
float minweight = 1.0;
for (int idx = 0; idx < probeInfluences; ++idx)
{
int i = probeIndex[idx];
if (abs(refIndex[i].w) < max_priority)
{
continue;
}
{
float w;
vec3 refcol = tapIrradianceMap(pos, dir, w, refSphere[i].xyz, i);
col += refcol*w;
wsum += w;
}
}
if (wsum > 0.0)
{
col *= 1.0/wsum;
}
return col;
}
void sampleReflectionProbes(inout vec3 ambenv, inout vec3 glossenv,
vec2 tc, vec3 pos, vec3 norm, float glossiness, bool errorCorrect)
{
// TODO - don't hard code lods
float reflection_lods = max_probe_lod;
preProbeSample(pos);
vec3 refnormpersp = reflect(pos.xyz, norm.xyz);
ambenv = sampleProbeAmbient(pos, norm);
float lod = (1.0-glossiness)*reflection_lods;
glossenv = sampleProbes(pos, normalize(refnormpersp), lod, errorCorrect);
#if defined(SSR)
if (cube_snapshot != 1)
{
vec4 ssr = vec4(0);
//float w = tapScreenSpaceReflection(errorCorrect ? 1 : 4, tc, pos, norm, ssr, sceneMap);
float w = tapScreenSpaceReflection(1, tc, pos, norm, ssr, sceneMap);
glossenv = mix(glossenv, ssr.rgb, w);
}
#endif
}
void debugTapRefMap(vec3 pos, vec3 dir, float depth, int i, inout vec4 col)
{
vec3 origin = vec3(0,0,0);
bool manual_probe = abs(refIndex[i].w) > 2;
if (manual_probe)
{
if (refIndex[i].w < 0)
{
boxIntersectDebug(origin, pos, i, col);
}
else
{
float r = refSphere[i].w; // radius of sphere volume
float rr = r * r; // radius squared
float t = 0.0;
sphereIntersectDebug(origin, dir, refSphere[i].xyz, rr, depth, col);
}
}
}
vec4 sampleReflectionProbesDebug(vec3 pos)
{
vec4 col = vec4(0,0,0,0);
vec3 dir = normalize(pos);
float d = length(pos);
for (int i = 1; i < refmapCount; ++i)
{
debugTapRefMap(pos, dir, d, i, col);
}
return col;
}
void sampleReflectionProbes(inout vec3 ambenv, inout vec3 glossenv,
vec2 tc, vec3 pos, vec3 norm, float glossiness)
{
sampleReflectionProbes(ambenv, glossenv,
tc, pos, norm, glossiness, false);
}
void sampleReflectionProbesLegacy(inout vec3 ambenv, inout vec3 glossenv, inout vec3 legacyenv,
vec2 tc, vec3 pos, vec3 norm, float glossiness, float envIntensity)
{
// TODO - don't hard code lods
float reflection_lods = max_probe_lod;
preProbeSample(pos);
vec3 refnormpersp = reflect(pos.xyz, norm.xyz);
ambenv = sampleProbeAmbient(pos, norm);
if (glossiness > 0.0)
{
float lod = (1.0-glossiness)*reflection_lods;
glossenv = sampleProbes(pos, normalize(refnormpersp), lod, false);
}
if (envIntensity > 0.0)
{
legacyenv = sampleProbes(pos, normalize(refnormpersp), 0.0, false);
}
#if defined(SSR)
if (cube_snapshot != 1)
{
vec4 ssr = vec4(0);
float w = tapScreenSpaceReflection(1, tc, pos, norm, ssr, sceneMap);
glossenv = mix(glossenv, ssr.rgb, w);
legacyenv = mix(legacyenv, ssr.rgb, w);
}
#endif
}
void applyGlossEnv(inout vec3 color, vec3 glossenv, vec4 spec, vec3 pos, vec3 norm)
{
glossenv *= 0.5; // fudge darker
float fresnel = clamp(1.0+dot(normalize(pos.xyz), norm.xyz), 0.3, 1.0);
fresnel *= fresnel;
fresnel *= spec.a;
glossenv *= spec.rgb*fresnel;
glossenv *= vec3(1.0) - color; // fake energy conservation
color.rgb += glossenv*0.5;
}
void applyLegacyEnv(inout vec3 color, vec3 legacyenv, vec4 spec, vec3 pos, vec3 norm, float envIntensity)
{
vec3 reflected_color = legacyenv;
vec3 lookAt = normalize(pos);
float fresnel = 1.0+dot(lookAt, norm.xyz);
fresnel *= fresnel;
fresnel = min(fresnel+envIntensity, 1.0);
reflected_color *= (envIntensity*fresnel);
color = mix(color.rgb, reflected_color*0.5, envIntensity);
}