SLLayerProtocol Protocol Reference Conforms to NSObject Declared in SLPublicProtocols.h expressionControls required method Returns an array containing all associated expression control effects (i.e. 3D Point Control, Angle Control etc.) @property (nonatomic, readonly) NSArray<SLProperty*> *expressionControls Declared In SLPublicProtocols.h – evaluateExpressions required method Call this method to force evaluate any attached expressions. By default Squall evaluates expressions whenever the time of the animation changes. - (void)evaluateExpressions Discussion You can also call evaluateExpressions on the SLAnimation containing the layer to force expression evaluation on all layers. Declared In SLPublicProtocols.h