Blog

View HTML 5 beta
The car rig project is intended for anyone wanting to create a vehicular animation in 3D Studio Max, and formed a module on my postgraduate degree. The project has since been updated to include oversteer, wheelspin and the option for a driver, as can be seen in the Motorway F1 video on the videos page.

A scripted rig is set up to allow for any four wheeled vehicle to be applied to it, which is manipulated using the sliders as you can see in the image below. All that is required is a model of a car, to edit the ground plane for any bumps if needed, and to draw the desired path the vehicle needs to take.

Speeds can be set to automatic or manual, allowing more control. The relevant forces that need to be applied to the car are automatically calculated, and the user then defines how much impact these forces will have. So a very heavy car with comparatively light suspension can be set to lean more in corners, while a lighter car, such as an F1 car with its stiffer chassis and suspension, will tend to bank less.





Similarly, forces applies upon acceleration and braking can be applied. This is accounted for by referencing frames in advance and behind to judge whether the car is accelerating, braking, or remaining at a constant speed. The faster the speed change, the greater the angle the vehicle will dip or raise. So under extreme braking, the front of the car will be pushed onto the front wheels, while the opposite will happen under heavy acceleration. A multiplier slider function is added to allow the user control over the amount that these forces should be applied - a cartoon dragster for example may have exaggerated effects and do a wheelie on acceleration, while a more conservative and realistic road car would react more gently.





Some of the features are automatic - such as the wheel rotation. This is calculated by working out the distance travelled in relation to the diameter of the wheel. A future development would be to allow wheel spin. On a similar theme, tweaks to manually control the steering may be beneficial, to give the impression of over or understeer. Oversteer in particular would be useful for rally cars. A change in grip levels could also be a future addition, to show the effects of driving on ice for example.


To control the steering and path, a spline is drawn. There is a look-ahead function to control the direction in which the wheels are pointing, so the vehicle begins to turn fractionally before the actual cornering effect begins, as in real life. As with everything else about this rig, this is also controllable how far ahead the function views to fine tune depending on the vehicle applied.

One thing that perhaps needs some work is the reaction over bumps, which seems a little forced. This obviously isn't a problem over flat ground, but over very harsh hills, the car should give the option to bounce a little more than it does, and this is something I shall continue to work on.

To demonstrate the rig, here are links to two further videos using a rally car and an F1 car. The F1 car has skinned suspension, as it is more of an unusual vehicle, with protruding wheels, and you will see it has an over-exaggerated effect to demonstrate the vertical movement, particularly as it bounces over the curbs.

Finally, a larger version of the video above can be found here. Other video sizes of all the clips here are on the videos page.

Related posts

 

    RegisterLogin

Comments [8]