Add extra visbility test & fix incorrect gaussian sampling implementa…

…tion
LuisaGroup · Apr 21, 2024 · 623aa52 · 623aa52
1 parent faf00f0
commit 623aa52
Showing 1 changed file with 8 additions and 9 deletions.
diff --git a/src/integrators/restir_di.cpp b/src/integrators/restir_di.cpp
@@ -382,14 +382,10 @@ class ReSTIRDirectLightingInstance final : public ProgressiveIntegrator::Instanc
     }
     void _perturb_sample(Expr<uint> frame_index, Expr<uint2> pixel_id, Expr<float> time) const noexcept {
         auto constexpr num_perturb_iter = 10u;
-        auto constexpr sample_gaussian = [](Expr<float2> u) noexcept {
-            Float2 uu = u;
-            uu.x = 2.f * abs(u.x - .5f);
-            auto x = ite(u.x < .5f, -1.f, 1.f) * sqrt(-log(uu));
-            $if(any(dsl::isnan(x))) {
-                x = make_float2(0.f);
-            };
-            return x;
+        auto constexpr sample_box_muller = [](Expr<float2> u) noexcept {
+            auto r = sqrt(clamp(-2.f * log(u.x), 0.f, 1.f));
+            auto theta = 2.f * pi * u.y;
+            return make_float2(r * cos(theta), r * sin(theta));
         };
         sampler()->start(pixel_id, frame_index);
         auto spectrum = pipeline().spectrum();
@@ -405,7 +401,7 @@ class ReSTIRDirectLightingInstance final : public ProgressiveIntegrator::Instanc
             // offset the sample location on the light surface
             $for(_, num_perturb_iter) {
                 auto candidate = reservoir;
-                auto perturbation = 0.01f * sample_gaussian(sampler()->generate_2d());
+                auto perturbation = 0.02f * sample_box_muller(sampler()->generate_2d());
                 candidate.sample.u_light_surface = clamp(reservoir.sample.u_light_surface + perturbation, 0.f, 1.f);
                 auto [L, pdf] = _evaluate_without_occlusion(candidate.sample, *it, wo, swl, time);
                 $if(reservoir.weight.target_pdf > 0.f & pdf > 0.f) {
@@ -545,6 +541,9 @@ class ReSTIRDirectLightingInstance final : public ProgressiveIntegrator::Instanc
                     if (node<ReSTIRDirectLighting>()->enable_decorrelation()) {
                         command_buffer << perturb(_total_frame_count, s.point.time).dispatch(resolution);
                     }
+                    if (node<ReSTIRDirectLighting>()->enable_visibility_reuse()) {
+                        command_buffer << visibility_reuse(_total_frame_count, s.point.time).dispatch(resolution);
+                    }
                 }
                 if (node<ReSTIRDirectLighting>()->enable_spatial_reuse()) {
                     for (auto j = 0u; j < num_spatial_reuse_pass; j++) {