Add neighbour selection heuristic controls

Author: MrMagnifico

.vscode/settings.json

@@ -88,9 +88,5 @@
         "bitset": "cpp",
         "regex": "cpp",
         "typeindex": "cpp"
-    },
-    "cmake.buildEnvironment": {
-        "embree_DIR": "C:/embree-4.3.1.x64.windows/lib/cmake/embree-4.3.1/",
-        "TBB_DIR": "C:/Program Files (x86)/Intel/oneAPI/tbb/2021.12/lib/cmake/tbb/"
     }
 }

src/ray_tracing/embree_interface.cpp

@@ -80,6 +80,7 @@ bool EmbreeInterface::closestHit(Ray& ray, HitInfo& hitInfo) const {
     rtcInterpolate0(rtcGetGeometry(m_scene, rayhit.hit.geomID), rayhit.hit.primID, rayhit.hit.u, rayhit.hit.v,
                     RTC_BUFFER_TYPE_VERTEX_ATTRIBUTE,   1, glm::value_ptr(hitInfo.texCoord),            2);
     hitInfo.material    = m_meshToMaterial.at(rayhit.hit.geomID);
+    hitInfo.geometryId  = rayhit.hit.geomID;
     ray.t               = rayhit.ray.tfar;
 
     // Debug draw ray and normal, then return true

src/rendering/neighbour_selection.cpp

@@ -3,11 +3,21 @@
 #include <algorithm>
 #include <random>
 
+
 bool areSimilar(const RayHit& lhs, const RayHit& rhs, const Features& features) {
-    // TODO: Expand to user-adjustable values (and maybe additional properties)
-    float depthFracDiff     = std::abs(1.0f - (lhs.ray.t / rhs.ray.t));             // Depth difference (greater than 10% leads to rejection) 
-    float normalsDotProd    = glm::dot(lhs.hit.normal, rhs.hit.normal);             // Normal difference (greater than 25 degrees leads to rejection)
-    if (depthFracDiff > 0.1f || normalsDotProd < 0.90630778703f) { return false; }  // TODO: Apply R&L instead of this lemming bullshit
+    // Same geometries
+    if (features.neighbourSameGeometry && lhs.hit.geometryId != rhs.hit.geometryId) { return false; }
+    
+    // Depth difference
+    float depthFracDiff = std::abs(1.0f - (lhs.ray.t / rhs.ray.t)); 
+    if (depthFracDiff > features.neighbourMaxDepthDifferenceFraction) { return false; }
+
+    // Normal angle difference
+    float maxDiffCos        = std::cos(features.neighbourMaxNormalAngleDifferenceRadians);
+    float normalsDotProd    = glm::dot(lhs.hit.normal, rhs.hit.normal);
+    if (normalsDotProd < features.neighbourMaxNormalAngleDifferenceRadians) { return false; }
+
+    // We passed the similarity test!
     return true;
 }
 

src/ui/ui.cpp

@@ -72,6 +72,9 @@ void UiManager::drawProjectTab() {
 }
 
 void UiManager::drawRayTracingTab() {
+    drawRayTracingNeighbourSelectionParams();
+    ImGui::Spacing();
+    ImGui::Separator();
     drawRayTracingFeaturesToggles();
     ImGui::Spacing();
     ImGui::Separator();
@@ -257,6 +260,14 @@ void UiManager::drawLightControls() {
     }
 }
 
+void UiManager::drawRayTracingNeighbourSelectionParams() {
+    if (ImGui::CollapsingHeader("Neighbour Selection Heuristics", ImGuiTreeNodeFlags_DefaultOpen)) {
+        ImGui::Checkbox("Same geometry", &config.features.neighbourSameGeometry);
+        ImGui::SliderFloat("Max depth difference fraction", &config.features.neighbourMaxDepthDifferenceFraction, 0.01f, 1.0f);
+        ImGui::SliderAngle("Max normal angle difference", &config.features.neighbourMaxNormalAngleDifferenceRadians, 0.0f, 90.0f);
+    }
+}
+
 void UiManager::drawRayTracingFeaturesToggles() {
     if (ImGui::CollapsingHeader("Features", ImGuiTreeNodeFlags_DefaultOpen)) {
         ImGui::Text("Common");

src/ui/ui.h

@@ -48,6 +48,7 @@ class UiManager {
 
     // Ray-tracing UI bits
     void drawRayTracingTab();
+    void drawRayTracingNeighbourSelectionParams();
     void drawRayTracingFeaturesToggles();
     void drawRayTracingParams();
 

src/utils/common.h

@@ -45,6 +45,7 @@ struct HitInfo {
     glm::vec3 barycentricCoord;
     glm::vec2 texCoord;
     Material material;
+    uint32_t geometryId;
 };
 
 struct RayHit {
@@ -106,6 +107,11 @@ struct Features {
     uint32_t numNeighboursToSample      = 5U;
     uint32_t spatialResampleRadius      = 10U;
 
+    // Neighbour selection heuristics controls
+    bool neighbourSameGeometry                      = false;
+    float neighbourMaxDepthDifferenceFraction       = 0.10f;
+    float neighbourMaxNormalAngleDifferenceRadians  = 0.436332f;
+
     // R-MIS/R-OMIS parameter(s)
     uint32_t maxIterationsMIS                               = 5U;
     NeighbourSelectionStrategy neighbourSelectionStrategy   = NeighbourSelectionStrategy::Random;