NASCAR 09 Input System and Driving Models

By: Mike DeVault and Guillermo J. Garcia-Sampedro

In NASCAR 09 we wanted to make a big improvement in the way the car handled out on the track when steered by the controller.  We were happy with the way that the steering wheel controls worked coming over from 08.  However, the inputs and handling when using the thumb-stick on the controller was an area we saw the need to improve on. 

The community was a big help in letting us know what adjustments needed to be made and we spent a lot of time researching what people were saying about our existing NASCAR 08 driving model.  In going through the feedback from playtests, media reviews and from the community, it became apparent that opinions were split on the matter of car handling.  Some really enjoyed the challenge of the simulation driving experience we delivered in 08 while others found the learning curve a bit too steep.  We were very happy that we had been able to deliver a simulation handling model that a lot of the hardcore fans were able to get behind, so for NASCAR 09 we set our sights on producing a second driving model geared for those looking for a more forgiving experience.  Additionally, we also targeted wholesale changes to the controller input model to give the player a better feel of the steering inputs regardless of if they were hardcore or more entry level fans of the game.

Guillermo J. Garcia-Sampedro is the Software Engineer on our team that we tapped on the shoulder to get the job done.  Game making is a hugely collaborative effort, however, Guillermo is very much to credit for the success of the controller inputs and handling model for NASCAR 09.  With that in mind, I think I’ll hand the reigns of this blog over to Guillermo, so he can tell you first hand the process behind the creation of what ultimately became our new controller input system and our new driving models (known as NORMAL and PRO Driving styles in NASCAR 09).

Take it away Guillermo…

Thank you, first of all, I would like to say thank you back at Mike for spending many hours helping me tune the thing. As Mike stated earlier, there was a huge challenge to make the game appeal to people without affecting the handling for those who already liked it. The very first thing that went into making the game handle like 09 was to check for the correct vehicle dimensions, the correctness of the center of gravity, the tire models and small things along these lines. As you can probably think, that in all took a lot of time to check and correct where necessary, it is a very time consuming task. After this was done, it became clear to us that we needed to make the physics engine scalable in realism as well, and since the game was originally meant to be a hardcore simulator, mainly driven with a steering wheel, then additional parameters to the physics engine were added to allow for such capabilities.

With the addition of these new parameters, the idea of the driving model system came along and after the usual ‘name shuffling’ process; the Normal/Pro modes became the final driving models that we were going to ship in the final game. This driving model system allowed us for a highly configurable physics system based on parameter blocks, all fully tunable by production, and all of that while in real time. This feature was also widely used for play testing and Q&A to find problems that were very difficult to reproduce under normal playing conditions but they could still happen in rare occasions. The Pro driving model that shipped in NASCAR’09 was basically the same driving model that shipped in NASCAR’08 but with revised geometry for the cars, revised dimensions and tire slip curves and other minor tweaks done to the physics system to make it more enjoyable while still maintaining the difficulty of it.

All these new physics model system and revised data provided us with a good baseline to start concentrating on the player’s side of the game, questions like, is it too hard?, too easy? With these goals in mind, great deal of attention was then paid to the gamepad controller. This was done because we all know that a gamepad is not the preferred input device for driving cars, and therefore a lot of those driving mechanics needed to be tailored for the gamepad before it could be made comparable to the steering wheel. The challenge proved a hard one to solve, but I must say that here was the moment when having a strong background on R/C vehicles really helped to come up with the solution for this particular problem. The idea of a driving game is the same as in R/C, where part of the problem is solving the issues with the physics, but the other big part of the problem is setting up the game controller to make the car feel more like a real car.  Two words were spoken of: fun and challenging, as the main goals for handling in NASCAR’09, and at the same time, nobody wanted the car to drive by itself either.

Custom tailoring the controller physics to match the physics of the car was a technological achievement and a huge team effort to get it just right. The entire team, and in particular Mike, they all provided invaluable feedback and that was key to make the final tweaks to create the handling model that shipped on NASCAR 09.