[editor] fixed gimbal lock when rotating an entity using the transfor…

…m property boxes
PanosK92 · Jan 1, 2025 · 7fd4ce5 · 7fd4ce5
1 parent 2f3393e
commit 7fd4ce5
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Showing 2 changed files with 29 additions and 19 deletions.
diff --git a/editor/Widgets/Properties.cpp b/editor/Widgets/Properties.cpp
@@ -204,28 +204,39 @@ void Properties::Inspect(const shared_ptr<Material> material)
     m_inspected_material = material;
 }
 
-void Properties::ShowTransform(shared_ptr<Entity> entity) const
+void Properties::ShowTransform(shared_ptr<Entity> entity) const 
 {
     if (component_begin("Transform", IconType::Component_Transform, nullptr, true, false))
     {
-        //= REFLECT ==================================================
-        Vector3 position = entity->GetPositionLocal();
-        Vector3 rotation = entity->GetRotationLocal().ToEulerAngles();
-        Vector3 scale    = entity->GetScaleLocal();
-        //============================================================
+        //= REFLECT =====================================
+        Vector3 position    = entity->GetPositionLocal();
+        Quaternion rotation = entity->GetRotationLocal();
+        Vector3 scale       = entity->GetScaleLocal();
+        //===============================================
+
+        // convert current rotation to Euler angles for display
+        static Vector3 last_frame_euler = rotation.ToEulerAngles();
+        Vector3 current_euler           = last_frame_euler;
 
         ImGui::AlignTextToFramePadding();
         ImGuiSp::vector3("Position (m)", position);
         ImGui::SameLine();
-        ImGuiSp::vector3("Rotation (degrees)", rotation);
+        ImGuiSp::vector3("Rotation (degrees)", current_euler);
         ImGui::SameLine();
         ImGuiSp::vector3("Scale", scale);
 
-        //= MAP ========================================================
+        // calculate the the rotation delta, convert it to a quaternion, and apply it, avoiding gimbal lock
+        Vector3 delta_euler         = current_euler - last_frame_euler;
+        last_frame_euler            = current_euler;
+        Quaternion delta_quaternion = Quaternion::FromEulerAngles(delta_euler);
+        rotation                    = delta_quaternion * rotation;
+        rotation.Normalize();
+
+        //= MAP ===========================
         entity->SetPositionLocal(position);
         entity->SetScaleLocal(scale);
-        entity->SetRotationLocal(Quaternion::FromEulerAngles(rotation));
-        //==============================================================
+        entity->SetRotationLocal(rotation);
+        //=================================
     }
     component_end();
 }

diff --git a/runtime/Math/Quaternion.h b/runtime/Math/Quaternion.h
@@ -114,7 +114,7 @@ namespace Spartan::Math
             );
         }
 
-        static inline Quaternion FromToRotation(const Vector3& start, const Vector3& end)
+        static Quaternion FromToRotation(const Vector3& start, const Vector3& end)
         {
             const Vector3 normStart = start.Normalized();
             const Vector3 normEnd   = end.Normalized();
@@ -144,7 +144,7 @@ namespace Spartan::Math
             }
         }
 
-        static inline Quaternion FromLookRotation(const Vector3& direction, const Vector3& up_direction = Vector3::Up)
+        static Quaternion FromLookRotation(const Vector3& direction, const Vector3& up_direction = Vector3::Up)
         {
             Quaternion result;
             const Vector3 forward = direction.Normalized();
@@ -165,9 +165,9 @@ namespace Spartan::Math
             return result;
         }
 
-        static inline Quaternion FromToRotation(const Quaternion& start, const Quaternion& end) { return start.Inverse() * end; }
+        static Quaternion FromToRotation(const Quaternion& start, const Quaternion& end) { return start.Inverse() * end; }
 
-        static inline Quaternion Lerp(const Quaternion& a, const Quaternion& b, const float t)
+        static Quaternion Lerp(const Quaternion& a, const Quaternion& b, const float t)
         {
             Quaternion quaternion;
 
@@ -183,7 +183,7 @@ namespace Spartan::Math
             return quaternion.Normalized();
         }
 
-        static inline Quaternion Multiply(const Quaternion& Qa, const Quaternion& Qb)
+        static Quaternion Multiply(const Quaternion& Qa, const Quaternion& Qb)
         {
             const float x     = Qa.x;
             const float y     = Qa.y;
@@ -254,7 +254,6 @@ namespace Spartan::Math
             }
         }
 
-         // Returns Euler angles in degrees
         Vector3 ToEulerAngles() const
         {
             // Derivation from http://www.geometrictools.com/Documentation/EulerAngles.pdf
@@ -289,9 +288,9 @@ namespace Spartan::Math
             );
         }
 
-        // Euler angles to quaternion (input in degrees)
-        static inline auto FromEulerAngles(const Vector3& rotation)                           { return FromYawPitchRoll(rotation.y * Helper::DEG_TO_RAD, rotation.x * Helper::DEG_TO_RAD, rotation.z * Helper::DEG_TO_RAD); }
-        static inline auto FromEulerAngles(float rotationX, float rotationY, float rotationZ) { return FromYawPitchRoll(rotationY * Helper::DEG_TO_RAD,  rotationX * Helper::DEG_TO_RAD,  rotationZ * Helper::DEG_TO_RAD); }
+        // euler angles to quaternion (input in degrees)
+        static Quaternion FromEulerAngles(const Vector3& rotation)                           { return FromYawPitchRoll(rotation.y * Helper::DEG_TO_RAD, rotation.x * Helper::DEG_TO_RAD, rotation.z * Helper::DEG_TO_RAD); }
+        static Quaternion FromEulerAngles(float rotationX, float rotationY, float rotationZ) { return FromYawPitchRoll(rotationY * Helper::DEG_TO_RAD,  rotationX * Helper::DEG_TO_RAD,  rotationZ * Helper::DEG_TO_RAD); }
 
         // Returns yaw in degrees
         float Yaw() const   { return ToEulerAngles().y; }