diff --git a/src/AcDream.App/Rendering/GameWindow.cs b/src/AcDream.App/Rendering/GameWindow.cs
index 7017a65..6df4d44 100644
--- a/src/AcDream.App/Rendering/GameWindow.cs
+++ b/src/AcDream.App/Rendering/GameWindow.cs
@@ -7942,6 +7942,11 @@ public sealed class GameWindow : IDisposable
                         if (ImGuiNET.ImGui.MenuItem(flyLabel, "Ctrl+Shift+F"))
                             ToggleFlyOrChase();
                     }
+                    // A8.F: spring-arm camera collision (live A/B toggle).
+                    if (ImGuiNET.ImGui.MenuItem("Collide Camera (spring arm)", "",
+                            AcDream.Core.Rendering.CameraDiagnostics.CollideCamera))
+                        AcDream.Core.Rendering.CameraDiagnostics.CollideCamera =
+                            !AcDream.Core.Rendering.CameraDiagnostics.CollideCamera;
                     ImGuiNET.ImGui.EndMenu();
                 }
                 ImGuiNET.ImGui.EndMainMenuBar();