Fixed an issue with DirectedPoint tangents

LibCarla/source/carla/road/Map.cpp

@@ -73,23 +73,29 @@ namespace road {
     }
   }
 
-  /// returns a pair containing first = width, second = tangent
+  /// Returns a pair containing first = width, second = tangent,
+  /// for an specific Lane given an s and a iterator over lanes
   template <typename T>
   static std::pair<float, float> ComputeTotalLaneWidth(
-    const T container, const float s, const LaneId lane_id) {
+      const T container,
+      const float s, const
+      LaneId lane_id) {
     const bool negative_lane_id = lane_id < 0;
-    float dist = 0.0;
-    float tangent = 0.0;
+    auto dist = 0.0;
+    auto tangent = 0.0;
     for (const auto &lane : container) {
       const auto current_polynomial =
           lane.second->template GetInfo<RoadInfoLaneWidth>(s)->GetPolynomial();
-      float current_dist = current_polynomial.Evaluate(s);
+      auto current_dist = current_polynomial.Evaluate(s);
+      auto current_tangent = current_polynomial.Tangent(s);
       if (lane.first != lane_id) {
         dist += negative_lane_id ? current_dist : - current_dist;
+        tangent += current_tangent;
       } else if (lane.first == lane_id) {
         current_dist *= 0.5;
+        current_tangent *= 0.5;
         dist += negative_lane_id ? current_dist : - current_dist;
-        tangent = current_polynomial.Tangent(s);
+        tangent += current_tangent;
         break;
       }
     }
@@ -213,6 +219,9 @@ namespace road {
       lane_tangent = computed_width.second;
     }
 
+    // Unreal's Y axis hack
+    lane_tangent *= -1;
+
     // get a directed point in s and apply the computed lateral offet
     DirectedPoint dp = road->GetDirectedPointIn(waypoint.s);
 

LibCarla/source/carla/road/Road.cpp

@@ -176,11 +176,15 @@ namespace road {
 
     const auto lane_offset = _info.GetInfo<element::RoadInfoLaneOffset>(clamped_s);
     const float offset = lane_offset->GetPolynomial().Evaluate(clamped_s);
+    const float tangent = lane_offset->GetPolynomial().Tangent(clamped_s);
 
+    // Apply road's lane offset record
     element::DirectedPoint p = geometry->GetGeometry().PosFromDist(clamped_s - geometry->GetDistance());
-    // Unreal's Y axis hack
+    // Unreal's Y axis hack (the minus on the offset)
     p.ApplyLateralOffset(-offset);
+    p.tangent += tangent;
 
+    // Apply road's elevation record
     const auto elevation_info = GetElevationOn(s);
     p.location.z = elevation_info.Evaluate(s);
     p.pitch = elevation_info.Tangent(s);

LibCarla/source/carla/road/Road.h

@@ -75,6 +75,10 @@ namespace road {
 
     std::unordered_map<SignId, signal::SignalReference>* getSignalReferences();
 
+    /// Returns a directed point on the center of the road (lane 0),
+    /// with the corresponding laneOffset and elevation records applied,
+    /// on distance "s".
+    /// - @ param s distance regarding the road to compute the point
     element::DirectedPoint GetDirectedPointIn (const float s) const;
 
     /// Returns a pair containing: