feat(anymocap): Allow overwriting tStart/tEnd/nStep of MarkerTracking (#988)

Author: melund

Tools/AnyMocap/MarkerTrackingSettings.any

@@ -52,8 +52,10 @@ Main.Studies.MarkerTracking =
   #define N_STEP_KINEMATICS round(1+(T_END-T_START)*Main.ModelSetup.C3DFileData.Header.VideoFrameRate)
   #endif
 
-  tStart = T_START;
-  tEnd = T_END;
-  nStep = N_STEP_KINEMATICS;
+  // Becarefull when overwriting these directly. It is important that
+  // timesteps match the frames and framerate of the C3D/BVH file. 
+  tStart ??= T_START;
+  tEnd ??= T_END;
+  nStep ??= N_STEP_KINEMATICS;
 
 };