Sign in to follow this  
rumblesushi

Basic 3D car physics, how to properly apply forces to wheels etc

Recommended Posts

rumblesushi    159
Hello,

I'm working on my first game at the moment, a 3D racing game for the web, using my proprietary engine.

Right now I'm just getting some basic car physics working. As performance is paramount, I'm representing the cars just as 3D rectangles. 4 particles and 5 constraints.

The particles represent the wheels. I'm playing around at the moment just with applying forces to the particles, steering etc.

However, I can't find a reference for 3D car physics. It would be very useful if I had some fundamentals on how to apply force to the wheels according to whether the car is FWD or RWD etc.

Should each wheel have it's own velocity, or should each wheel simply apply force to a single velocity on the car?

Right now to represent a RWD car I'm applying most of the force on the rear wheels, with just a small amount on the front wheels, with rotated velocity for steering. Presumably for a FWD drive car you simply only apply force on the front wheels.

On the RWD test I'm doing, the car's pivot point feels like it's too far back, at the very back of the car basically. In real life, it is the front of the car that swings around, with the pivot point being at least somewhat to the rear, but it feels slightly wrong.

What additional forces do I need to apply? I've heard people mention normal force, but it's not something I'm acquainted with in the fairly basic physics experiments I've done. When I've seen it mentioned, it seems almost like a centrifugal force.

And if you know of a solid reference for 3D car physics from scratch, that would be great.

Also, I'm not developing a simulation. I want the handling and feel to be very much more on the arcadey side, a la Ridge Racer, Daytona, Burnout etc.

But even being arcade style, obviously the cars need to feel like cars :)

Cheers,
RumbleSushi

Share this post


Link to post
Share on other sites
rumblesushi    159
Thanks BMC, I'll look that up.

I forgot to say actually, once I'm happy with the basic mechanics and handling, the next step is to implement drift physics, as the game is arcade style touge game, so drifting is very important.

Share this post


Link to post
Share on other sites
rumblesushi    159
Also, what is generally considered the best way to implement friction in a racing game?

I've heard several people say friction is tricky.

In the physics experiments I've done, including verlet based soft body dynamics, I always use the basic velocity *= friction, where friction is a damping value around 0.99 etc. I guess this is considered air drag.

Even in arcade racing games, do people generally use surface friction in addition to air drag?

Cheers.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this