Download source files here.

This tutorial will show you an easy way to rig a vehicle that can be used for a car chase to have control over the animation to achieve some sliding, tilting and banking effects so you can emulate a realistic action.

At the moment I'm working on an animated short about a very well recognized superhero, whose identity can't be revealed at this time, that contains long car chase sequences. Part of the animation team is currently working on it and I saw my team trying to animate the vehicles by adjusting the pivot point over time and of course creating several keyframes to achieve the right action. So I came up with the idea of creating a simple system of nulls parented in an order that allows you have control over all those movements without having to waist time trying to adjust the objects pivot point.

Let's start by opening a clean new scene in Lightwave layout.

1. Load the object file named truck_tutorial.lwo.
   

2. Now create a null object by hitting 'ctrl+n' and give it a name. Click 'Ok'.
   

3. Clone the null object four times by hitting 'ctrl+c' and write in the field '4'. Click 'Ok'.
   

4. Rename the nulls, use the following names: 'null_MASTER', 'null_front', 'null_back', 'null_R' and 'null_L'.
   

5. Now to make tings easier, press the '2' key on the main keyboard pad to toggle to the top view. Change the view mode to front face wireframe so we can see the nulls.

6. Select 'null_front' and move it on the Z-axis so it gets aligned to the front wheels axis.
   
   Do the same with the 'null_back' object but in this case, align it to the rear wheels axis. Next step is to move the 'null_R' object on the X axis aligning it to the right side wheels . Last but not least, move the 'null_L' object to be aligned to the left side wheels.

7. Open the scene editor so you can see the objects in the tree. Select the 'null_front' object and hit 'm' to bring up its motion panel. click on the 'Parent Item' drop down menu and select 'null_MASTER' to be the parent.
   
   Now select null_back and in the motion panel, select 'null_front' as the parent. Do the same with the rest of the nulls, parenting 'null_R' to 'null_back' and 'null_L' to 'null_R'. To finish parenting, grab the 'truck_tutorial' object and parent it to the last object in the hierarchy, in this case, the 'null_L' object. As a result, you should have the following structure:
   
   null_MASTER
      null_front
         null_back
            null_R
               null_L
                  truck_tutorial

Now that everything is set we can move on and start animating.

Test drive.

8. Select 'null_MASTER', go to frame 60 and pull the Z axis blue arrow to move the entire hierarchy to the front as shown.
   
   'Auto Key' should be on. Now we want to draw some curves on the path. using the left arrow key on the keyboard go back some frames in the timeline. Now move the X axis red arrow to the left.
   
   Go some more frames back in the timeline and move the object to the right. As a result, we have an 'S' like path drawn.

9. Next step is to adjust the heading rotation. Hit the 'y' key to select the rotate tool. Move the timeline slider to the last keyframe created. Adjust the red handle so the object aligns to the path.
   
   Move the slider to the next keyframe and adjust the handle to align the object to the direction of the path. Now move the slider to a position between keyframes and adjust the heading so the object starts to adopt the position of the next keyframe.It will make that slippery effect of the car sliding on the rode when steering left and right.

Here comes the magic. What we want to do now is to exaggerate the motion by making the vehicle bank rotate to one side and the other. Notice that until now I've been moving just the 'null_MASTER' object.

10. Change the screen mode to whether camera view or perspective view. Move the timeline slider to the keyframe that describes the curve to the right. Grab the 'null_R' object and drag the blue handle to rotate the bank so the vehicle separates the left wheels from the road.
    
    Therefore, go a few frames back and and set the bank value back to '0' using the numeric panel on the bottom left corner of the screen. Now move the slider to a few frames ahead the main banking keyframe and set the value to '0' again.

11. Then move the timeline slider to the keyframe that describes the curve to the left. Select the 'null_L' object and rotate it on the bank so the right hand wheels separate from the road.
    
    Now, as we did in step 10, go back and forth a few keyframes and bring the bank value to 0 so all the tyres are making contact with the road before and after the banking rotation.

Make a preview. The result should be close to the preview movie attached to the Downloads section at the beginning of this tutorial. In this ocasion I animated a cartoonish van so I exaggerated the motions to a point where you can understand clearly the use of each controller. The null_front and null_back objects can be used to make the car roll over to the front when crashing against an obstacle or to make that fast launch effect in a race rising the front tires out of the road.

Final note: The hierarchy of the nulls may vary depending on the desired effect. Have fun and keep working!

Bio.- Alejandro Parrilla started his career as an illustrator in an age of transition between the traditional techniques and the digital world. After some time in that field he decided to take a further step and joined the 3D environment falling entirely in love with it. Now his goal is to find his place in the industry as a cgi artist. To contact Alejandro send an email to alejoide@hotmail.com.