# Animating The Rudder This page goes through the steps needed to animate the rudder of the aircraft.     ### Basic Animation To animate the rudder, you'll need to first create a point (generally using the format `Rudder`), and then place it on the rotational axis of the rudder mesh. Note that the pivot must be aligned with the rotational axis. With that done you can now link the mesh to the rudder bone with the **link** tool![Link Tool Icon](images/3_Models_And_Textures/Aircraft/animations/aileron/icon_link.png). {{< image-center src="images/3_Models_And_Textures/Aircraft/animations/rudder/rudder_1.png" alt="The Rudder Mesh Animation Point" >}}   The animation of the rudder is done over 4 frames (0 to3):
FrameLeft Aileron
0Neutral position
1LEFT (20°-25° angle)
2Neutral position
3RIGHT (20°-25° angle)
    ### Mechanisms As with other parts, you may have additional mechanisms to add. In the rudder for the example aircraft used here, there are two cables that directly link the rudder to the rudder pedals in the cockpit. To animate these you would need to create two more [PLOT](animations-overview/#PLOT)s and place them at the intersection between the cable and the *rudder*, naming them using the standard convention: `Rudder_Aux1` and `Rudder_Aux2`. Since these two must move with the rudder, they need to be linked to the Rudder helper.   Next you would need to create another two [PLOT](animations-overview/#PLOT)s and place them at the intersection between the cable and the *fuselage*. These will again be named using the same convention: `Rudder_Aux3` and `Rudder_Aux4`. Since these two shouldn't move with the rudder they should be linked to the helper [HIPS](animations-overview/#HIPS). {{< image-center src="images/3_Models_And_Textures/Aircraft/animations/rudder/rudder_2.png" alt="Helper Positions" >}}   We also want to ensure that the cables are kept apart from the fuselage when they follow the movement of the rudder, so you'd create a LookAt Constraint between `Rudder_Aux1` and `Rudder_Aux3`, and between `Rudder_Aux2` and `Rudder_Aux4`. After constraint PLOTs, you'd link mesh objects to them: right cable to `Rudder_Aux1` and left cable to `Rudder_Aux2`.     ### Rear Wheels We're going to look at a more complex element of the model that is specific to the rudder: having a tail wheel that is linked to the rudder position. To make the wheel follow the rotation of the rudder, we need to constrain the mechanism with the rudder helper.   To start with, on the mesh we can see that the axis of rotation of the wheel is fixed to a static element: {{< image-center src="images/3_Models_And_Textures/Aircraft/animations/rudder/rudder_3.png" alt="Static Wheel Axis Element" >}}   We can also see that the rudder is linked by two chains to the wheel: {{< image-center src="images/3_Models_And_Textures/Aircraft/animations/rudder/rudder_4.png" alt="The Mobile Chain Elements Of The Rudder Wheel" >}}   So, with this setup, we want the wheel to rotate along with the chains at the same time as when the rudder is moved using the rudder pedals.   To create this correctly, you'd need a new helper - called something like `CenterUpLeg` - and this helper will allow us to animate the rear landing gear (just a small movement of deformation when the plane will land). This would be placed at the junction of the landing gear and the fuselage and be linked to the [HIPS](animations-overview/#HIPS) helper. {{< image-center src="images/3_Models_And_Textures/Aircraft/animations/rudder/rudder_5.png" alt="The Wheel Helper" >}}   Now we need to constrain the rotation of the wheel with the rotation of the Rudder. For that, we create a new PLOT, and name it `CenterLeg` and then we place it on the rotational axis of the wheel mechanism. The PLOT must be aligned with the axis, not just be placed on it, and be linked to the `CenterUpLeg` helper. To constrain its rotation, you would go to the **Animation** menu, select **Constraints**, then select the **Orientation constraint**. You can now link the plot with the Rudder helper. {{< image-center src="images/3_Models_And_Textures/Aircraft/animations/rudder/rudder_7.png" alt="Orientation Constraint In 3DS Max" >}} Now you can link objects with the same rotational axis to the PLOT `CenterLeg`. We now need to constrain the chains to follow the rotation. For that, we create two PLOTS (like previous rudder mechanisms) and name them `CenterLeg_MasterAux1` and `CenterLeg_MasterAux2` and those will be linked with the rudder helper. Next, we'd create two more PLOTs and name them `CenterLeg_MasterAux1.1` and `CenterLeg_MasterAux2.1` and those will be linked with the `CenterLeg` Plot.   After that, we create a LookAt constraint between PLOTs: `CenterLeg_MasterAux1` with `CenterLeg_MasterAux1.1` and `CenterLeg_MasterAux2` with `CenterLeg_MasterAux2.1`. After creating LookAt constraints, we link the left chain to `CenterLeg_MasterAux1` and the right chain to `CenterLeg_MasterAux2`. ![FInal Connections For The Rudder And Wheel](images/3_Models_And_Textures/Aircraft/animations/rudder/rudder_9.png)**NOTE**: You can use [Skinning](animations-overview/#skinning) for the chains instead of linking them using PLOTs.