diff --git a/src/code_800029B0.c b/src/code_800029B0.c
index beba2e490..30263e4f9 100644
--- a/src/code_800029B0.c
+++ b/src/code_800029B0.c
@@ -68,7 +68,8 @@ s32 gIsMirrorMode = 0;
 f32 vtxStretchY = 1.0f;
 Lights1 D_800DC610[] = {
     gdSPDefLights1(175, 175, 175, 255, 255, 255, 0, 0, 120),
-    gdSPDefLights1(115, 115, 115, 255, 255, 255, 0, 0, 120),
+    //! @todo impl lighting in custom track origin value 115 instead of 209. Hack fix for lighting for now
+    gdSPDefLights1(209, 209, 209, 255, 255, 255, 0, 0, 120),
 };
 UNUSED s32 pad_800029B0 = 0x80000000;
 s16 gCreditsCourseId = COURSE_LUIGI_RACEWAY;
diff --git a/src/engine/HM_Intro.cpp b/src/engine/HM_Intro.cpp
index e27d5db0c..320ea9e45 100644
--- a/src/engine/HM_Intro.cpp
+++ b/src/engine/HM_Intro.cpp
@@ -3,6 +3,7 @@
 #include "HM_Intro.h"
 
 #include "port/Game.h"
+#include "port/interpolation/FrameInterpolation.h"
 
 extern "C" {
 #include "main.h"
@@ -64,7 +65,7 @@ void HarbourMastersIntro::HM_InitIntro() {
 	0x60, 20, 10, 0x49, 0x49, 0x49
     );
 
-    gEditor.AddObject("lus", &lusPos, &lusRot, &lusScale, nullptr, 1, Editor::GameObject::CollisionType::BOUNDING_BOX, 10, &DespawnValue, -1);
+    //gEditor.AddObject("lus", &lusPos, &lusRot, &lusScale, nullptr, 1, Editor::GameObject::CollisionType::BOUNDING_BOX, 10, &DespawnValue, -1);
 }
 
 void HarbourMastersIntro::HM_TickIntro() {
@@ -115,6 +116,7 @@ void HarbourMastersIntro::SpagBob(FVector& pos, IRotator& rot, f32 bobAmp, f32 b
 }
 
 void HarbourMastersIntro::HM_DrawIntro() {
+    FrameInterpolation_ShouldInterpolateFrame(false);
     HarbourMastersIntro::Setup();
 
     gSPMatrix(gDisplayListHead++, &gGfxPool->mtxScreen, G_MTX_NOPUSH | G_MTX_LOAD | G_MTX_PROJECTION);
@@ -122,21 +124,28 @@ void HarbourMastersIntro::HM_DrawIntro() {
     gDPSetRenderMode(gDisplayListHead++, G_RM_AA_ZB_OPA_SURF, G_RM_AA_ZB_OPA_SURF2);
     gDPSetEnvColor(gDisplayListHead++, 0x00, 0x00, 0x00, 0x00);
 
+    FrameInterpolation_RecordOpenChild("spag_ship", 0);
     Mat4 mtx_spaghettiShip;
     ApplyMatrixTransformations(mtx_spaghettiShip, _pos, _rot, _scale);
     render_set_position(mtx_spaghettiShip, 0);
     gSPDisplayList(gDisplayListHead++, ship1_spag1_mesh);
+    FrameInterpolation_RecordCloseChild();
 
+    FrameInterpolation_RecordOpenChild("ship2", 0);
     Mat4 mtx_ship2;
     ApplyMatrixTransformations(mtx_ship2, _ship2Pos, _ship2Rot, _scale);
     render_set_position(mtx_ship2, 0);
     gSPDisplayList(gDisplayListHead++, ship2_SoH_mesh);
+    FrameInterpolation_RecordCloseChild();
 
+    FrameInterpolation_RecordOpenChild("ship3", 0);
     Mat4 mtx_ship3;
     ApplyMatrixTransformations(mtx_ship3, _shipPos, _shipRot, _scale);
     render_set_position(mtx_ship3, 0);
     gSPDisplayList(gDisplayListHead++, ship3_2Ship_mesh);
+    FrameInterpolation_RecordCloseChild();
 
+    FrameInterpolation_RecordOpenChild("hm_geo", 0);
     Mat4 mtx_geo;
     ApplyMatrixTransformations(mtx_geo, _hPos, _hRot, _hScale);
     render_set_position(mtx_geo, 0);
@@ -146,13 +155,17 @@ void HarbourMastersIntro::HM_DrawIntro() {
     gSPDisplayList(gDisplayListHead++, castle_map_002_mesh);
     gSPDisplayList(gDisplayListHead++, road_map_001_mesh);
     gSPDisplayList(gDisplayListHead++, water_water1_mesh);
+    FrameInterpolation_RecordCloseChild();
 
+    FrameInterpolation_RecordOpenChild("hm_lus", 0);
     Mat4 lusMtx;
     ApplyMatrixTransformations(lusMtx, lusPos, lusRot, lusScale);
     render_set_position(lusMtx, 0);
     gSPDisplayList(gDisplayListHead++, (Gfx*)"__OTR__hmintro/poweredbylus");
+    FrameInterpolation_RecordCloseChild();
 
     HarbourMastersIntro::Sync();
+    FrameInterpolation_ShouldInterpolateFrame(true);
 }
 
 void HarbourMastersIntro::Setup() {
diff --git a/src/engine/Matrix.cpp b/src/engine/Matrix.cpp
index b55a9b89f..4c87d7eb7 100644
--- a/src/engine/Matrix.cpp
+++ b/src/engine/Matrix.cpp
@@ -74,6 +74,7 @@ void ApplyMatrixTransformations(Mat4 mtx, FVector pos, IRotator rot, FVector sca
     f32 sine1, cosine1;
     f32 sine2, cosine2;
     f32 sine3, cosine3;
+    FrameInterpolation_ApplyMatrixTransformations((Mat4*)mtx, pos, rot, scale);
 
     // Compute the sine and cosine of the orientation (Euler angles)
     sine1 = sins(rot.pitch);
diff --git a/src/engine/courses/Course.cpp b/src/engine/courses/Course.cpp
index bbc9455fe..94d634373 100644
--- a/src/engine/courses/Course.cpp
+++ b/src/engine/courses/Course.cpp
@@ -23,12 +23,13 @@ extern "C" {
 #include "render_courses.h"
 #include "collision.h"
 #include "actors.h"
+#include "math_util.h"
 extern StaffGhost* d_mario_raceway_staff_ghost;
 }
 
 Course::Course() {
-    // Props.Name = "Course Name";
-    // Props.DebugName = "CName";
+    Props.SetText(Props.Name, "Blank Track", sizeof(Props.Name));
+    Props.SetText(Props.DebugName, "blnktrck", sizeof(Props.DebugName));
     Props.SetText(Props.CourseLength, "100m", sizeof(Props.CourseLength));
     // Props.Cup = FLOWER_CUP;
     // Props.CupIndex = 3;
@@ -134,7 +135,7 @@ void Course::LoadO2R(std::string trackPath) {
     }
 }
 
-// Load stock track
+// Load stock and o2r tracks
 void Course::Load() {
 
     // Load from O2R
@@ -150,6 +151,8 @@ void Course::Load() {
             ParseCourseSections(sections, size);
             func_80295C6C();
             Props.WaterLevel = gCourseMinY - 10.0f;
+        } else {
+            printf("Course.cpp: Custom track sections are invalid\n");
         }
         return;
     }
@@ -337,7 +340,7 @@ void Course::Render(struct UnkStruct_800DC5EC* arg0) {
     if (!TrackSectionsPtr.empty()) {
         gSPSetGeometryMode(gDisplayListHead++, G_SHADING_SMOOTH);
         gSPClearGeometryMode(gDisplayListHead++, G_LIGHTING);
-       // set_track_light_direction(D_800DC610, D_802B87D4, 0, 1);
+        set_track_light_direction(D_800DC610, D_802B87D4, 0, 1);
         gSPTexture(gDisplayListHead++, 0xFFFF, 0xFFFF, 0, G_TX_RENDERTILE, G_ON);
         gSPSetGeometryMode(gDisplayListHead++, G_SHADING_SMOOTH);
 
diff --git a/src/engine/courses/Course.h b/src/engine/courses/Course.h
index 0a0eff823..a1a7d2f4b 100644
--- a/src/engine/courses/Course.h
+++ b/src/engine/courses/Course.h
@@ -96,7 +96,7 @@ typedef struct Properties {
         j["Name"] = Name ? Name : "";
         j["DebugName"] = DebugName ? DebugName : "";
         j["CourseLength"] = CourseLength ? CourseLength : "";
-        j["AIBehaviour"] = AIBehaviour ? AIBehaviour : "";
+        //j["AIBehaviour"] = AIBehaviour ? AIBehaviour : "";
         j["LakituTowType"] = LakituTowType;
         j["AIMaximumSeparation"] = AIMaximumSeparation;
         j["AIMinimumSeparation"] = AIMinimumSeparation;
@@ -133,10 +133,22 @@ typedef struct Properties {
         j["MinimapFinishlineY"] = Minimap.FinishlineY;
         j["MinimapColour"] = {static_cast<int>(Minimap.Colour.r), static_cast<int>(Minimap.Colour.g), static_cast<int>(Minimap.Colour.b)};
         // SkyboxColors - assuming SkyboxColors can be serialized similarly
-        // j["Skybox"] = Skybox; // Implement your serialization logic here
+
+        #define TO_INT(value) static_cast<int>(value)
+        j["Skybox"] = {
+            TO_INT(Skybox.TopRight.r), TO_INT(Skybox.TopRight.g), TO_INT(Skybox.TopRight.b),
+            TO_INT(Skybox.BottomRight.r), TO_INT(Skybox.BottomRight.g), TO_INT(Skybox.BottomRight.b),
+            TO_INT(Skybox.BottomLeft.r), TO_INT(Skybox.BottomLeft.g), TO_INT(Skybox.BottomLeft.b),
+            TO_INT(Skybox.TopLeft.r), TO_INT(Skybox.TopLeft.g), TO_INT(Skybox.TopLeft.b),
+            TO_INT(Skybox.FloorTopRight.r), TO_INT(Skybox.FloorTopRight.g), TO_INT(Skybox.FloorTopRight.b),
+            TO_INT(Skybox.FloorBottomRight.r), TO_INT(Skybox.FloorBottomRight.g), TO_INT(Skybox.FloorBottomRight.b),
+            TO_INT(Skybox.FloorBottomLeft.r), TO_INT(Skybox.FloorBottomLeft.g), TO_INT(Skybox.FloorBottomLeft.b),
+            TO_INT(Skybox.FloorTopLeft.r), TO_INT(Skybox.FloorTopLeft.g), TO_INT(Skybox.FloorTopLeft.b)
+        };
         j["Sequence"] = static_cast<int>(Sequence);
 
         j["WaterLevel"] = static_cast<float>(WaterLevel);
+        #undef CAST_TO_INT
 
         return j;
     }
@@ -156,7 +168,7 @@ typedef struct Properties {
         strncpy(CourseLength, j.at("CourseLength").get<std::string>().c_str(), sizeof(CourseLength) - 1);
         CourseLength[sizeof(CourseLength) - 1] = '\0'; // Ensure null termination
 
-        AIBehaviour = j.at("AIBehaviour").get<std::string>().c_str();
+        //AIBehaviour = j.at("AIBehaviour").get<std::string>().c_str();
         LakituTowType = j.at("LakituTowType").get<int>();
 
         AIMaximumSeparation = j.at("AIMaximumSeparation").get<float>();
@@ -215,6 +227,39 @@ typedef struct Properties {
         Minimap.Colour.g = j.at("MinimapColour")[1].get<uint8_t>();
         Minimap.Colour.b = j.at("MinimapColour")[2].get<uint8_t>();
         //textures = nullptr; // Deserialize textures if present
+
+        Skybox.TopRight.r = j.at("Skybox")[0].get<uint8_t>();
+        Skybox.TopRight.g = j.at("Skybox")[1].get<uint8_t>();
+        Skybox.TopRight.b = j.at("Skybox")[2].get<uint8_t>();
+
+        Skybox.BottomRight.r = j.at("Skybox")[3].get<uint8_t>();
+        Skybox.BottomRight.g = j.at("Skybox")[4].get<uint8_t>();
+        Skybox.BottomRight.b = j.at("Skybox")[5].get<uint8_t>();
+
+        Skybox.BottomLeft.r = j.at("Skybox")[6].get<uint8_t>();
+        Skybox.BottomLeft.g = j.at("Skybox")[7].get<uint8_t>();
+        Skybox.BottomLeft.b = j.at("Skybox")[8].get<uint8_t>();
+        
+        Skybox.TopLeft.r = j.at("Skybox")[9].get<uint8_t>();
+        Skybox.TopLeft.g = j.at("Skybox")[10].get<uint8_t>();
+        Skybox.TopLeft.b = j.at("Skybox")[11].get<uint8_t>();
+
+        Skybox.FloorTopRight.r = j.at("Skybox")[12].get<uint8_t>();
+        Skybox.FloorTopRight.g = j.at("Skybox")[13].get<uint8_t>();
+        Skybox.FloorTopRight.b = j.at("Skybox")[14].get<uint8_t>();
+
+        Skybox.FloorBottomRight.r = j.at("Skybox")[15].get<uint8_t>();
+        Skybox.FloorBottomRight.g = j.at("Skybox")[16].get<uint8_t>();
+        Skybox.FloorBottomRight.b = j.at("Skybox")[17].get<uint8_t>();
+
+        Skybox.FloorBottomLeft.r = j.at("Skybox")[18].get<uint8_t>();
+        Skybox.FloorBottomLeft.g = j.at("Skybox")[19].get<uint8_t>();
+        Skybox.FloorBottomLeft.b = j.at("Skybox")[20].get<uint8_t>();
+
+        Skybox.FloorTopLeft.r = j.at("Skybox")[21].get<uint8_t>();
+        Skybox.FloorTopLeft.g = j.at("Skybox")[22].get<uint8_t>();
+        Skybox.FloorTopLeft.b = j.at("Skybox")[23].get<uint8_t>();
+
         Sequence = static_cast<MusicSeq>(j.at("Sequence").get<int>());
         WaterLevel = j.at("WaterLevel").get<float>();
     }
diff --git a/src/engine/editor/SceneManager.cpp b/src/engine/editor/SceneManager.cpp
index a2de6656c..c825431de 100644
--- a/src/engine/editor/SceneManager.cpp
+++ b/src/engine/editor/SceneManager.cpp
@@ -69,7 +69,7 @@ namespace Editor {
     void LoadLevel(std::shared_ptr<Ship::Archive> archive, Course* course, std::string sceneFile) {
         SceneFile = sceneFile;
 
-        if (archive) {
+        if (archive && (course != nullptr)) {
             auto initData = std::make_shared<Ship::ResourceInitData>();
             initData->Parent = archive;
             initData->Format = RESOURCE_FORMAT_BINARY;
diff --git a/src/port/Game.cpp b/src/port/Game.cpp
index 4cea9c5e2..63faab45c 100644
--- a/src/port/Game.cpp
+++ b/src/port/Game.cpp
@@ -141,7 +141,8 @@ void CustomEngineInit() {
     gWorldInstance.AddCup(gBattleCup);
 
     /* Set default course; mario raceway */
-    SelectMarioRaceway();
+    //SelectMarioRaceway(); // This results in a nullptr
+    gWorldInstance.CurrentCourse = mario;
     gWorldInstance.CurrentCup = gMushroomCup;
     gWorldInstance.CurrentCup->CursorPosition = 3;
     gWorldInstance.CupIndex = 0;
@@ -601,10 +602,6 @@ void* GetCourse(void) {
     return gWorldInstance.CurrentCourse;
 }
 
-void SetCourseByClass(void* course) {
-    gWorldInstance.CurrentCourse = (Course*) course;
-}
-
 struct Actor* CM_GetActor(size_t index) {
     if (index < gWorldInstance.Actors.size()) {
         AActor* actor = gWorldInstance.Actors[index];
diff --git a/src/port/Game.h b/src/port/Game.h
index 14cc0edf6..3cc63afc0 100644
--- a/src/port/Game.h
+++ b/src/port/Game.h
@@ -143,8 +143,6 @@ void* GetCourse(void);
 
 void SetCourseById(s32 course);
 
-void SetCourseByClass(void* course);
-
 struct Actor* CM_GetActor(size_t index);
 void CM_DeleteActor(size_t index);
 struct Actor* CM_AddBaseActor();
diff --git a/src/port/interpolation/FrameInterpolation.cpp b/src/port/interpolation/FrameInterpolation.cpp
index 438c10c0a..b11eb0391 100644
--- a/src/port/interpolation/FrameInterpolation.cpp
+++ b/src/port/interpolation/FrameInterpolation.cpp
@@ -8,6 +8,7 @@
 #include "FrameInterpolation.h"
 #include "matrix.h"
 #include "engine/Matrix.h"
+#include "src/engine/CoreMath.h"
 
 extern "C" {
 #include "math_util.h"
@@ -85,6 +86,7 @@ enum class Op {
     SetTranslateRotate,
     SetTextMatrix,
     SetMatrixPosRotScaleXY,
+    SetApplyMatrixTransformations,
 };
 
 typedef pair<const void*, uintptr_t> label;
@@ -108,6 +110,13 @@ union Data {
         u8 mode;
     } matrix_mult;
 
+    struct {
+        Mat4* matrix;
+        FVector pos;
+        IRotator rot;
+        FVector scale;
+    } matrix_applytransformations;
+
     struct {
         Mat4* matrix;
         Vec3fInterp b;
@@ -578,6 +587,13 @@ struct InterpolateCtx {
                             mtxf_translation_x_y_rotate_z_scale_x_y(*gInterpolationMatrix, tmp32[0], tmp32[1], tmp_vec3s[0], tmp_vec3f[0]);
                             break;
                         }
+                        case Op::SetApplyMatrixTransformations: {
+                            lerp_vec3f(&tmp_vec3f, (Vec3f*)&old_op.matrix_applytransformations.pos, (Vec3f*)&new_op.matrix_applytransformations.pos);
+                            lerp_vec3s(&tmp_vec3s, (int16_t*)&old_op.matrix_applytransformations.rot, (int16_t*)&new_op.matrix_applytransformations.rot);
+                            lerp_vec3f(&tmp_vec3f2, (Vec3f*)&old_op.matrix_applytransformations.scale, (Vec3f*)&new_op.matrix_applytransformations.scale);
+
+                            ApplyMatrixTransformations(*gInterpolationMatrix, *(FVector*)&tmp_vec3f, *(IRotator*)&tmp_vec3s, *(FVector*)&tmp_vec3f2);
+                        }
                     }
                 }
             }
@@ -694,6 +710,12 @@ void FrameInterpolation_RecordMatrixMult(Mat4* matrix, MtxF* mf, u8 mode) {
     append(Op::MatrixMult).matrix_mult = { matrix, *mf, mode };
 }
 
+void FrameInterpolation_ApplyMatrixTransformations(Mat4* matrix, FVector pos, IRotator rot, FVector scale) {
+    if (!is_recording)
+        return;
+    append(Op::SetApplyMatrixTransformations).matrix_applytransformations = { matrix, pos, rot, scale };
+}
+
 void FrameInterpolation_RecordMatrixTranslate(Mat4* matrix, Vec3f b) {
     if (!is_recording)
         return;
diff --git a/src/port/interpolation/FrameInterpolation.h b/src/port/interpolation/FrameInterpolation.h
index 30187c808..8acb0a83a 100644
--- a/src/port/interpolation/FrameInterpolation.h
+++ b/src/port/interpolation/FrameInterpolation.h
@@ -7,11 +7,13 @@
 
 #ifdef __cplusplus
 
+#include "src/engine/CoreMath.h"
 #include <unordered_map>
 
 
 
 std::unordered_map<Mtx*, MtxF> FrameInterpolation_Interpolate(float step);
+void FrameInterpolation_ApplyMatrixTransformations(Mat4* matrix, FVector pos, IRotator rot, FVector scale);
 
 extern "C" {
 #endif
diff --git a/src/port/resource/importers/TrackSectionsFactory.cpp b/src/port/resource/importers/TrackSectionsFactory.cpp
index 2abce35d4..64a3b0a2f 100644
--- a/src/port/resource/importers/TrackSectionsFactory.cpp
+++ b/src/port/resource/importers/TrackSectionsFactory.cpp
@@ -44,9 +44,10 @@ ResourceFactoryXMLTrackSectionsV0::ReadResource(std::shared_ptr<Ship::File> file
     if (!FileHasValidFormatAndReader(file, initData)) {
         return nullptr;
     }
-    
+
     auto section = std::make_shared<TrackSectionsO2RClass>(initData);
-    auto child = std::get<std::shared_ptr<tinyxml2::XMLDocument>>(file->Reader)->FirstChildElement("TrackSections");
+    auto child =
+        std::get<std::shared_ptr<tinyxml2::XMLDocument>>(file->Reader)->FirstChildElement()->FirstChildElement();
 
     while (child != nullptr) {
         std::string childName = std::string(child->Name());
diff --git a/src/port/ui/ContentBrowser.cpp b/src/port/ui/ContentBrowser.cpp
index 5390d8a9d..ee109d290 100644
--- a/src/port/ui/ContentBrowser.cpp
+++ b/src/port/ui/ContentBrowser.cpp
@@ -127,7 +127,7 @@ namespace Editor {
             if (!track.SceneFile.empty()) { // has scene file
                 std::string label = fmt::format("{}##{}", track.Name, i_track);
                 if (ImGui::Button(label.c_str())) {
-                    SetCourseByClass(track.course);
+                    gWorldInstance.CurrentCourse = track.course;
                     gGamestateNext = RACING;
                     SetSceneFile(track.Archive, track.SceneFile);
                     break;
@@ -136,7 +136,7 @@ namespace Editor {
                 std::string label = fmt::format("{} {}", ICON_FA_EXCLAMATION_TRIANGLE, track.Name);
                 if (ImGui::Button(label.c_str())) {
                     track.SceneFile = track.Dir + "/scene.json";
-                    SetCourseByClass(track.course);
+                    gWorldInstance.CurrentCourse = track.invalidTrack.get();
                     SetSceneFile(track.Archive, track.SceneFile);
                     SaveLevel();
                     Refresh = true;
@@ -240,10 +240,10 @@ namespace Editor {
                     
                     auto course = std::make_unique<Course>();
                     course->LoadO2R(dir);
-                    gWorldInstance.Courses.push_back(std::move(course));
                     LoadLevel(archive, course.get(), sceneFile);
                     LoadMinimap(archive, course.get(), minimapFile);
-                    Tracks.push_back({course.get(), sceneFile, name, dir, archive});
+                    Tracks.push_back({nullptr, course.get(), sceneFile, name, dir, archive});
+                    gWorldInstance.Courses.push_back(std::move(course));
                 } else { // The track does not have a valid scene file
                     const std::string file = dir + "/data_track_sections";
                     
@@ -256,9 +256,8 @@ namespace Editor {
                         course->Id = (std::string("mods:") + name).c_str();
                         course->Props.SetText(course->Props.Name, name.c_str(), sizeof(course->Props.Name));
                         course->Props.SetText(course->Props.DebugName, name.c_str(), sizeof(course->Props.Name));
-
                         auto archive = manager->GetArchiveFromFile(file);
-                        Tracks.push_back({course.get(), "", name, dir, archive});
+                        Tracks.push_back({std::move(course), nullptr, "", name, dir, archive});
                     } else {
                         printf("ContentBrowser.cpp: Track '%s' missing required track files. Cannot add to game\n  Missing %s/data_track_sections file\n", name.c_str(), dir.c_str());
                     }
diff --git a/src/port/ui/ContentBrowser.h b/src/port/ui/ContentBrowser.h
index f077f7283..001d1a3b3 100644
--- a/src/port/ui/ContentBrowser.h
+++ b/src/port/ui/ContentBrowser.h
@@ -10,7 +10,8 @@ public:
     ~ContentBrowserWindow();
 
     struct Tracks {
-        Course* course;
+        std::unique_ptr<Course> invalidTrack; // If not nullptr, user needs to create a scene file for this track.
+        Course* course; // A valid custom track. Used to reset the Courses array on a file system refresh.
         std::string SceneFile;
         std::string Name;
         std::string Dir; // Directory