Lesson 4 - Suspension

The next stage is the suspension of the car. For this we will need a rear, front and full body suspension. Start by creating three CV curves and place them at the front, back and middle of the car to act as the controllers, remember to make them look like the action they control. In this case I used double headed arrows.

Next group the geometry of the car (minus the wheels) twice. You should now have 3 groups for the car like below:

The highlighted groups are the body geometry. Notice the wheels are seperate.

Rename the groups similarly to how they are in the example. To make it so the car rotates when the controller is translated up, we have to use an expression.

Select the "Front_suspension_group" and open the Expression editor (Window > Animation Editor)  then select the "rotateX" attribute. Add the following expression:

Front_suspension_group.rotateX

=

Front_suspension_control.translateY

;

It should look like this:

What does this do? This links the "Front_suspension_group" with the "Front_suspension_control". Furthermore, it states that when the controller translates on the Y axis, the group will rotate on the X.

Do this for the rear suspension too.

NOTE: One of your suspension controllers will rotate the car when moving down the Y instead of up. To fix this add *-1 as seen in the above example. This will reverse the direction.

Lastly, we need a controller for the full body suspension. This is a simple point constraint from the main_suspension_control to the Body_grp.

Don't forget to limit the controllers if you need to.

Locking Controllers

Limitting controllers allows you to control how far a controller will go before it stops meaning it can be restricted. Locking controllers is different.

Locking allows you to disable certain axis and tools from being used allowing you to essentially block anyone from breaking the rig by doing things they aren't supposed to.

To lock a controller, click it and go to Window > General Editor > Channel Control. Switch to the Locked tab at the top and in the Non-Locked section find anything you want to restrict.

Here, I've selected the main_suspension_control  and since it only needs to move on the Y to control the suspension, I've chosen to lock the Rotate and Scale tools and also the other translate axis. This now stops you from moving the controllers.

Keep in mind. This will also lock you out so make sure you do this at the end of the rig.