diff --git a/src/models.py b/src/models.py
index d5de638..98b955c 100644
--- a/src/models.py
+++ b/src/models.py
@@ -161,9 +161,6 @@ class Keyframe:
     time: Decimal
     """Point of time of the keyframe. Stored as decimal for high precision."""
 
-    parameter: Parameter
-    """Parameter targeted by frame value."""
-
     value: KeyframeValue = None
     """Targeted state value reached by reaching the keyframe."""
 
@@ -175,27 +172,17 @@ class Keyframe:
 class EngineKeyframe:
     """A keyframe for engine use during rendering."""
 
-    keyframes: list[Keyframe]
-    """Reference keyframes."""
+    frame: Keyframe
+    """Reference keyframe."""
 
     delta: Decimal
     """Remaining time in seconds relative to previous keyframes."""
 
-    def __iter__(self) -> Iterator[Keyframe]:
-        return iter(self.keyframes)
-
-    def get(self, parameter: Parameter) -> Keyframe:
-        """Get keyframe for parameter found among the keyframes. Assumed to exist only once. Exception raised, if parameter not defined by keyframes."""
-        for k in self.keyframes:
-            if k.parameter == parameter:
-                return k
-        raise ValueError(f"Parameter [{parameter}] not given among keyframes.")
-
 
 @dataclass_json
 @dataclass
 class Track:
-    """Contains a sequence of keyframes for specified fixtures."""
+    """Contains a sequence of keyframes for specified fixtures and parameter."""
 
     id: str
     """Unique identifier for track."""
@@ -203,6 +190,9 @@ class Track:
     name: str
     """Human readable name."""
 
+    parameter: Parameter
+    """Parameter targeted by frame value."""
+
     fixture_ids: list[str]
     """Fixtures by ids targeted by track."""
 
@@ -218,10 +208,10 @@ class EngineTrack:
     """Reference track."""
 
     keyframes: list[EngineKeyframe] = field(default_factory=list)
-    """Relative keyframes of track."""
+    """Relative engine keyframes of track."""
 
     current: EngineKeyframe | None = None
-    """Keyframes before the next keyframes. Trigger time has been reached."""
+    """Keyframe before the next keyframe. Trigger time has been reached."""
 
     @property
     def next(self) -> EngineKeyframe | None:
@@ -238,20 +228,12 @@ class EngineTrack:
     def __post_init__(self):
         # Calculate relative keyframes
         sorted_keyframes = sorted(self.track.keyframes, key=lambda k: k.time)
-        prev_time: Decimal = Decimal.from_float(0)
-        curr_time: Decimal = Decimal.from_float(0)
-        keyframes = []
-        for k, next in zip(sorted_keyframes, [*sorted_keyframes[1:], None]):
-            curr_time = k.time
-            keyframes.append(k)
-
-            if next is None or k.time != next.time:
-                self.keyframes.append(EngineKeyframe(keyframes, curr_time - prev_time))
-
-                if next is not None:
-                    keyframes = []
-                    prev_time = curr_time
-                    curr_time = next.time
+        # Make keyframe time relative for engine use
+        for previous, current in zip([None, *sorted_keyframes[1:]], sorted_keyframes):
+            delta = current.time
+            if previous:
+                delta -= previous.time
+            self.keyframes.append(EngineKeyframe(current, delta))
 
     def step(self, step_size: Decimal):
         """Step keyframes forward by given step."""
@@ -340,8 +322,9 @@ if __name__ == "__main__":
                     Track(
                         "89idf",
                         "Ceiling flicker",
+                        Parameter.BRIGHTNESS,
                         ["98iwd"],
-                        [Keyframe(Decimal.from_float(0), Parameter.BRIGHTNESS, 1)],
+                        [Keyframe(Decimal.from_float(0), 1)],
                     )
                 ],
             )