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// Copyright 2009 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#include "render/pathtracer/PathStructs.ih"
#include "render/pathtracer/PathTracerDefines.ih"
#include "render/pathtracer/ShadowCatcher.ih"
#include "render/pathtracer/TransparentShadow.ih"
#include "render/Renderer.ih"
#include "common/Ray.ih"
#include "common/World.ih"
#include "math/random.ih"
// c++ shared
#include "PathTracerDataShared.h"
#include "lights/LightDispatch.ih"
#include "lights/LightShared.h"
OSPRAY_BEGIN_ISPC_NAMESPACE
SYCL_EXTERNAL bool shadowCatcher(const PathContext &pathContext,
PathState &pathState,
PathVertex &pathVertex,
const Ray &ray,
const RayCone &rayCone,
const uniform FeatureFlagsHandler &ffh)
{
if (!(pathContext.context->backgroundRefraction
? pathState.specularTransmissionPath
: pathState.straightPath))
return false;
// TODO use MIS as well
// consider real (flagged) geometries with material and move into light loop
// (will also handle MIS)
if (pathState.shadowCatcherDist <= ray.t
&& pathState.shadowCatcherDist > ray.t0) {
// "postIntersect" of shadowCatcher plane
pathVertex.dg.Ns = pathVertex.dg.Ng =
make_vec3f(pathContext.context->shadowCatcherPlane);
if (dot(ray.dir, pathVertex.dg.Ng) >= 0.f)
pathVertex.dg.Ns = pathVertex.dg.Ng = neg(pathVertex.dg.Ng);
pathVertex.dg.renderer = &pathContext.context->super;
pathVertex.dg.P = ray.org + pathState.shadowCatcherDist * ray.dir;
const float rayConeWidth = rayCone.width
+ rayCone.dwdt * pathState.shadowCatcherDist; // propagate to hit
const float eps =
calcEpsilon(pathVertex.dg.P, ray.dir, pathState.shadowCatcherDist);
pathVertex.dg.P = pathVertex.dg.P + eps * pathVertex.dg.Ng;
vec3f unshaded = make_vec3f(0.f); // illumination without occluders
vec3f shaded = make_vec3f(0.f); // illumination including shadows
const World *uniform world = pathContext.world;
const uniform PathTracerData &pathtracerData =
*((const uniform PathTracerData *)world->pathtracerData);
// TODO use lightsSamples
for (uniform uint32 i = 0; i < pathContext.numLights; i++) {
const Light *uniform light = pathtracerData.lights[i];
float dummy;
const vec2f s =
LDSampler_get3LightSamples(pathState.ldSampler, i, true, dummy);
Light_SampleRes ls =
Light_dispatch_sample(light, pathVertex.dg, s, pathState.time, ffh);
// skip when zero contribution from light
if (reduce_max(ls.weight) <= 0.0f | ls.pdf <= PDF_CULLING)
continue;
// evaluate a white diffuse BRDF
const float brdf =
clamp(dot(ls.dir, pathVertex.dg.Ns)); // * one_over_pi cancels anyway
// skip when zero contribution from material
if (brdf <= 0.0f)
continue;
// test for shadows
Ray shadowRay;
setRay(shadowRay, pathVertex.dg.P, ls.dir, 0.0f, ls.dist, pathState.time);
// connect ray cone to point on light
RayCone shadowCone;
shadowCone.width = rayConeWidth;
shadowCone.dwdt = -rayConeWidth * rcp(ls.dist);
// Trace ray in clipping geometries scene, fill array with ray intervals
RayIntervals rayIntervals;
traceClippingRay(pathContext.world, shadowRay, rayIntervals, ffh);
const vec3f unshadedLightContrib = pathState.throughput * ls.weight
* brdf; // * misHeuristic(pathContext, ls.pdf, brdf);
unshaded = unshaded + unshadedLightContrib;
shaded = shaded
+ transparentShadow(pathContext.context,
pathContext.world,
unshadedLightContrib,
shadowRay,
shadowCone,
rayIntervals,
pathState.currentMedium,
ffh);
}
// order of args important to filter NaNs (in case unshaded.X is zero)
const vec3f ratio = min(
pathState.throughput * shaded * rcp(unshaded), pathState.throughput);
// alpha blend-in black shadow
pathState.throughput = ratio;
pathState.contribution = make_vec3f(0.f);
return true;
}
// update dist for potential next intersection (if transparent)
pathState.shadowCatcherDist -= ray.t;
return false;
}
OSPRAY_END_ISPC_NAMESPACE
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