Basic XPresso car tutorial

In this mini tutorial I shall show you how to make the wheels of the car rotate as the car is moved, while also rotating the light (siren). Now this is a very basic tutorial just to give you a taste for what Xpresso can do ( I am not an expert in Xpresso nor do I claim to be, this tutorial is meant an introduction for someone that hasn't used it before).

The result shown in the below link
basic_Xpresso_car1

Step 1, create your main car body, wheels and siren and drop the wheels/siren onto the car object in the Object manager ( making them children of the car object, easy way to make them move with the car). Then place all these into a null object. Make sure the car object is set at 0,0,0 in the scene.

Step 2, right click on the null object in the Object manager and goto Cinema4d tags, then go down to Xpresso. This will place an Xpresso tag onto the Null object ( it doesn't really matter where you place this tag as it doesnt effect the results).

Step 3, now double click on the tag to open the Xpresso manager and drag the car into it. Do the same with the wheels and siren. Then arrange them like shown below.

Step 4, click on the red square on the right of the car (node) and go down to coordinates, position, then position Z ( this is the axis direction in which the car will travel ).

Step 5, now click on the wheel blue square top left and go down to coordinates, Rotation, Rotation P ( as this is the axis you will want the wheel to rotate around). Do this for all the wheels.

step 6, now drag the car's red dot to each of the wheels blue dots this will connect them all. Now when you move the car in the view port the wheels will rotate.

step 7, now for the light. This is slightly different to the wheels as we want it to rotate as the car moves but we dont want it to rotate as fast, so I have used a range mapper to control it. So follow the image below to make a Range mapper ( by right clicking on an empty part in the Xpresso Editor)

First set the blue top right square of the light/siren to coordinates, Rotation, Rotation H ( this is the axis we need to rotate the light on when the car moves forward). Now connect that to the Output on the Range mapper ( red dot) and then connect the input of the Range mapper to the cars Position Z ( red dot). Now when you move the car the light should rotate.

step 8, select the Range mapper box/node in the editor and then goto the Attribute manager and in the input/ output range select "percent". Then change the output upper to 1%. This will make it rotate at a slower rate when the car is being moved.

Well thats about it. Like I said this is a very basic set up just to give you a first look at Xpresso. Xpresso is a very powerful system and one that can speed up and improve your workflow. I will post some more tutorials on Xpresso soon and hope that this one is useful to someone.

scene file:

click to download

(v12 file)