Our ReVolt Pub

I've noticed with cars that aren't 100% precise in their handling, the AI tends to drive them in a very wavy fashiong - no straight lines. Back and forth, back and forth. This increases if the car has especially slow turning response (including high inertia) or low grip. On a shall corner, the AI tends to steer a little into the corner, but a little too far so it'll swing back to compensate - a little too far, so it'll swing back to compensate again which usually results in the car losing control and crashing into the inside of the corner. Its really annoying how the AI does this.

Anyone have a good solution for how to avoid it, either in car params or AI params?

Right now I have my cars with mildly high inertia (not too high or they really lose control) because it makes the handling of the car feel much more smooth, responsive and realistic, and it keeps the car from instantly changing direction when it hits a bump in the road.

One of my cars has almost twice as much friction in the back tires as the front, and it still drives in a wavy pattern.

I have experienced very similar to your observations.
I believe it's something to do with the OVER & UNDER settings in the AI section.
Just as a recomendation, delete the whole Car AI Details section and retest your car, see if you still get the same results, don't worry, the car will still load and work without that section, I guess it uses a default setting if one can't be found.

I remeber you stating that that changing a certain value increased your AI's lap times, I would be very interested in what data and findings you have summised and proved, please get in touch personally, either by email or through the Pub.

That reminds me that I needed to insert and best my best AI profile:
If you want to test this out, do some test runs with the car you want to use it on and check their race times. Then insert this AI and test the race times again, and compare the difference. Note that its designed for cars which are having "wavy driving" problems, so not all cars will need it.

Be sure to replace the bottom five values with whatever you think is appropriate for the car.

Now, I don't actually know what does what in the AI section - this AI is kind of a mesh between Humma and Volken AI values, and it just happens to work pretty well. I did some experimenting at one point and wrote down some notes that may or may not be accurate. Its really, really hard to tell what's going on with these values based on observation only.

Here's some notes I wrote:
OverThresh - higher values are how quickly they turn inward?
OverRange - lower values seem to promote smaller zigzags?

Is there any company that has the source code for Re-Volt that we can ask about this stuff?

Track AI is easier to work with - you can see what is happening!

Start a 12-car, 20-lap race with MAKEITGOOD and F4 pressed. Leave your car at the start line and position the camera over the corner you want to work on - you can look straight down and watch the cars go by.

This way, you can pick out where the cars are wandering; usually they vere off-line at 1 of the AI nodes. I think this is because the change in racing line angle is too great for the more sensitive cars. If you add more AI nodes (say, 2-3 times as many), you can reduce this angle and make it easier for the cpu to cope.

You can make adjustments without stopping the race - the cars will ignore the new nodes until you save your efforts (don't forget to make a copy of your original .fan). Then you can watch the cars through again, and repeat if necessary.

Sometimes, a well positioned 30mph slow down can do the job. Often, if you have fast cars, a couple of 30mph nodes on the straight before the corner, but with a 'racing speed' node immediately before the corner, sets the cars up. Don't be afraid to experiment, there are a lot of nodes to try!

Geoff

Oh great, now I don't know whether nodes should be close together or far apart.

What bothers me with nodes that are close together to specify exactly how the AI should ride out a turn is that it inherently ruins whatever advantage a car that can handle tight corners has over one with less control. They're both required to navigate the turn in the same way, so assuming the cars have equal potential in the hands of a decent driver, one of them will always do worse in the hands of the AI.

On the other hand, if the nodes were placed further apart, it seems like the AI would take the corners at whatever pace they can handle. The problem occurs when the AI tries to do a maneuver that it can't handle and either understeers into a wall or oversteers and ends up out of control.

If you're designing cars to be realistic like I was before, there doesn't seem to be a whole lot you can do about this, since realistically some cars didn't have ideal performance and it was up to the driver to make up for any weaknesses on the part of the car's handling. But right now, with the futuristic cars, there's no reason why the cars can't be designed to eliminate oversteer and understeer. So if the car is negotiating a turn in a way that's resulting in bad things, there's probably some car parameters that can be adjusted to fix that.

I just don't know if those parameters are the car's performance stats or in the AI section.

It must be a compromise. If you make all the cars behave the same on the track, they will lose their individuality; if you make the track cope with all the cars, the better cars will lose their advantage, though the fastest should benefit.

You really need a different .fan for each class of car you race.

Perhaps it is an idea to have a 'control' car and make the track ideal for it?

As for distance between AI nodes, if it is too far then some cpu cars can ,seemingly, forget where they are going and can lose the racing line completely. I've had this happen on the middle deck of Toytanic 1.

Geoff