Race and Vehicle Simulations

Kunos Simulazioni have grown up in the public eye; starting with their first sim, ‘namie’ (freely available), they went on to code the highly respected and deeply flawed masterpiece that was netKar Pro (their first commercial sim), before maturing with the official Ferrari F1 Sim (Ferrari Virtual Academy). Now they’re back with their second commercial product, Assetto Corsa. Will they deliver on their talent this time?

Jon Denton was invited to take a sneak peak at development …

Campagnano di Roma is a peaceful Roman town in the Latium region of Italy. Dating back over a thousand years, it’s sleepy, confined streets reflect a calm solitude that must echo the distant, catastrophic wars of antiquity when the race fans roll into town. For this town is but a few short miles from the Autodromo Vallelunga Piero Taruffi, the sand oval track built back in the 50s and now, homologated by the FIA and expanded, scene of many an F1-test and where, this sunny spring time morning, I find myself ensconced in the offices of Kunos Simulazioni for a test-drive of my very own.

Kunos Simulazioni (Kunos) have been around the sim-racing world for quite a while now, and regular readers of AutoSimSport will need no introduction. Most famous for netKar Pro (nKPro)—regarded by many as the finest commercial simulator currently available (if by that one refers to driving feel and accuracy of the tyre model)—that was developed on a shoestring and a diet of boiled rice back in 2005, Kunos’ involvement with sim-racing can be traced further back than that—all the way back to the turn of the century and the original, free netKar (namie) which Kunos founder Stefano Casillo had developed out of his shed (metaphorically speaking) and on top of which sat the core of nKPro.

netKarPro was not well received on its release back in 2006, primarily due to problems with netcode, but not helped by a community that, at the time, felt that the moon on a stick should just be the beginning of what they deserved from a racing sim. Kunos was, and still is, a small team (but not, I add, just one man), and the reaction at the time came as quite a shock. Now, moving on to their new sim Assetto Corsa, meaning essentially ‘race setup’, they are moving forward with their eyes open much wider, buoyed no doubt by their professional advancement that has seen them swap the cold windy flats of Trieste for the more gentle climes of Southern Italy and now far more aware of what sim-racers might want from a title.

Having A Chat

‘When I was making netKarPro, I used to look around on forums and I would see people talking so much about this or that feature, but the reality was different,” Stefano tells me in his clean, Italian-modern office. ‘We put in things such as the “full mode” where drivers would have to wait for repairs, or the pitboard being the only information for a driver in a race. These things were nice, but when it came down to it, maybe only twenty percent of players would use them.’

Does this hint at a lower focus on ‘hard core’ simulation elements in AC?

‘No, I don’t think so,’ Stefano says, ‘we are building the physics and graphics engines from the ground-up from scratch, and we are aiming for as much realism as possible in tyre behaviour and fundamental vehicle dynamics. Using an evolution of the existing netKarPro engine would have involved too much fudging, a ground up rebuild also helps us take more advantage of new technology, both in software and hardware.’

Aristotelis Vasilakos (Aris) joined the Kunos team last year to assist on working with the physics of AC, (you may know him from his work on the P&G mod for GTR2), and he felt this an opportune time to air his thoughts. ‘The first thing, for us, when we started to work, is that we need a physics engine that is workable across as many platforms as possible, and I mean car platforms. In netKarPro, the base physics were focussed on single-seater race cars, which pull high G-ratings and are very light, often using slick tyres with stiff sidewall construction. This meant that, when we started to introduce heavier cars that had more bodywork and overall inertia, we could not make them feel as good to drive as the original, single-seater cars.’

This was something Aris and I discussed in last issue’s piece on Ferrari Virtual Academy 2011 Adrenaline Pack, where the newly introduced Ferrari 458 Trofeo Cup car did not feel like a solid, planted GT car, but a little more spongy, like a road car.

‘Yes, as I said to you at the time,’ confirms Aris, ‘it was a balancing act to set that car up, {and} this is just the sort of thing we want to avoid. AC is an open platform for modders,’ he reveals, ‘and we hope, over time, to see a wide variety of cars being created in the community, but also, we plan to release a variety of different machinery in the core release. Every sim-racer has a different opinion on what is the finest race car or road car to drive—not everyone wants to race F1 cars or Formula Fords—so we want to offer a selection on initial release that will offer something to everyone’s tastes.’

Already then we can see a wholesale departure from the naivety of nKPro. So how, I ask, have they got around this limitation, what is the starting point?

The first thing we wanted to get right is a simple car,’ explains Aris, ‘a road-going, front wheel drive hatchback that can generate about 1-G in cornering forces on road tyres. If we started at this point, it should be relatively straightforward to move up the scale to cars with more power and grip.’ Aris turns with a grin to Stefano, who chirps up, “So we used my car! The Fiat 500 Abarth.’

At 165BHP and 1,035KG, the 500, or cinquecento, will represent a vehicle quite close to what many of us may have sampled on the road. In my experience, this is often where many sims fall down. There are sims on the market that can do a great job with lower speed road cars, but their physics model stumbles when presented with beastly race cars on slicks and with tons of aero grip. At the same time, other sims do the race cars well and come to pieces with softer sprung, road cars equipped with tyres more suited to comfort than speed. Arguably, from the sim-racer’s perspective, both are race-able, and both require very different driving styles.

‘Going back to what we were saying earlier, about the hardcore sim part,’ Stefano says watching me sip my fourth espresso of the morning (it was a 6AM flight out of London that had brought me here!), ‘what I came to realise with netKarPro is that there is a group of people in the community who want things as hardcore and realistic as they can get. They want to replicate what it is like to race cars in real life; but there are many who want a more open and free experience. Many don’t want to be penalised for a white line infringement, or made to wait patiently for a rear wing adjustment, and even among those who do, not all of them have the time to indulge in it. When you have to spend hours making a setup for a race, and practicing a track to have it perfect, sometimes sim-racing becomes a bit like work.’ A sentiment to which I can only agree, having spent enough hours on setup pages myself. ‘I am not saying that this is not something some people enjoy, but there should be a choice, and there is no reason not to make a sim with a hardcore physics model, but with gameplay elements that don’t force the driver into being an engineer, or having to take the whole thing so seriously; this is our hobby, our passion, it should be fun!’

Experience talking, and I can’t say I disagree; I remember talking to Stefano about such things in 2005, and thinking that making a sim as close to real life as possible was exactly what I wanted, but I can say that in my netKarPro ‘career’, I have raced using ‘full mode’ precisely twice. Both times I had to work on setups for hours and hours outside of full mode, and practice the circuit in question for hours to ensure I would not crash in the race. It was a challenge, but was it fun? The key, for me, is a sim with balance, where I can give myself that challenge if I so choose it, but if I want a more casual experience then it should be there as an option.

It’s generally regarded in the community that the best realisations of race tracks in modern sim-racing are the laser scanned efforts by iRacing, and Kunos have embraced this technology for AC. Marco Massarutto, production director for Kunos, feels that, for AC to compete in the marketplace, they need to invest in this area. ‘Really, aside from the driving feel and physics, the areas we want to improve over previous titles are the racing environments. We are working with an all-new DX11-based graphics engine, and so we really want to do justice to the circuits we have in AC.’

Those circuits that have been confirmed currently include Magione, Monza, Imola, and the slightly less Italian Silverstone. ‘We had to go with laser scanning, the bar for circuit quality was pushed forward when this technology was introduced, and we are very happy with the results so far,’ Marco tells me.

Big name licences such as Silverstone and Monza surely don’t come easily, and I ask him about the challenges involved.

‘Silverstone and Monza were great to work with, but you call up some circuits, and there can be someone on the end of the line who really has no idea what you are talking about, these people are motorsports people, they don’t know anything about video games. We’ve had people thinking we want to put on a race at their circuit, people thinking I want to paint pictures of their circuit, and on one occasion I had the phone slammed down on me!’

Some absolutely stunning WIP pictures have been posted around on the AC Facebook page, and the standard of graphical artistry being put into these tracks belies a deep passion for the pursuit.

‘We are very proud of some of the circuits we have, going to Monza for the laser scan was a special time for all of us, it is a cathedral to motor racing’s history, and while it may sometimes seem like a boring circuit, especially in a Fiat 500, when you are inside the circuit there is such a feeling of history and passion for the sport.’ Nuvolari, Caracciola, Rosemeyer, Ascari, Fangio, Moss, Hill, Clark, Surtees, Stewart, Fittipaldi, Andretti, Lauda, Piquet, Prost, Senna, Schumacher, Alonso, Vettel—since 1922, this place has crowned kings. ‘We really want to do it justice—if we can put just a piece of that special feeling into our simulator, then I will die a happy man.’

The Italian feel of the circuits on offer may not be a big surprise given that Kunos is a largely Italian concern, but the announcement of Silverstone hints that, as the development moves along, we may see more of an international feel to the sim. ‘I am working very hard on securing a good selection of circuits,’ confirms Marco. ‘It’s still early days, but it’s important for us to go to release with enough circuits to present drivers with a wide enough selection to keep them occupied.’

What about the flexibility of the racing environment? Can we expect a dynamic surface, wet weather, marble build up, maybe some leaves floating majestically in the breeze?

‘We’re not really committing to a massive feature set at this stage,’ Stefano replies, ‘we want to walk before we can run, {and} we are so early in the development process that the importance, for us, at this stage, is getting the basics right. It all depends on how things go with the implementation of the base, core simulator, and the solidity of components such as the physics, graphics and multiplayer components as well as AI that will determine what features we look at later in the development cycle.’

AI? So this won’t just be an online sim?

‘Not at all. I’m not sure I believe in going down only one route nowadays,’ Stefano muses. ‘People sometimes just want to have a bit of a drive around for fun against AI, where they can pause the game and setup things to their preference. The more serious online racer is not the only sim-racer out there, and we want AC to be enjoyed by as many people as possible.’

So, online serious simmer, offline casual simmer, what about the car nuts?

‘Well, we hope to have a good spread of cars in the initial release, hopefully something for everyone,’ Aris chirps, brightly. ‘We’re still working on many licences, but cars like the KTM X-Bow, Formula Abarth, Fiat 500, and Ferrari P4/5 Competizione already bring a good spread of differing machinery to the sim, and a vintage singleseater is something we’re working on too. The important thing, for us, is that they feel right, and so with the licences we have acquired, we have ensured full access to the machines in question, as well as all the data available on the setup and overall design of the cars.’

This bodes well for those seeking an authentic ride; unfettered access to the car in question is a must for accurate simulation, and Stefano confirms my thought when he says, ‘We don’t see ourselves making the sort of sim that comes out with three of four hundred cars, because with the size of team we have, and the attention to detail we want to give these vehicles, that could take years and years. Aris and I have recently spent an entire day just talking about and working on the vintage single-seater’s suspension. It was a good, productive day, but at the same time, we want to get the feel of these cars as good as we can get them, and for that we’re focussing on the details.’

There has been clear indication on the AC website that this sim will be open for modders to work on their own content for the sim—how much focus, I ask, eyeing another espresso, is being given to this area of the sim?

‘Because from the start we knew we wanted the sim to be moddable, we have built the software like a framework,’ explains Aris. ‘This means that we should be able to release some relatively simple tools that will let mod teams work on new content, or modifications to the sim or GUI. We want to make it so that modders don’t find it too hard to implement what they need. In the past, this was difficult as netKar was not built with any of this in mind. With AC, we want to introduce something that people can enjoy both as a racing sim and also as a launch pad for their creativity.’

It all sounds jolly grand, doesn’t it? The enthusiasm this small team have to create a simulator that is not just about racing, but also about driving, enamours me greatly. The, sheer, visceral joy of piloting a motor car is something they want to deliver to the home driver, and with their pedigree, you feel that they can do it.

Perhaps sensing that another espresso may have been a little too much, the lads from Kunos suggest I occupy my mind with something other than caffeine—do you, they inquire, want to have a go?

Having A Go

No sooner was it said than done, and I was thrown into their handy bucket seat and presented with a choice of cars and tracks. Now, being something of a veteran at trying sims for the first time with an audience, my focus was to pick up something with a manageable power-to-weight ratio and basic handling that I could easily relate to. Hmm, Fiat 500 Abarth, or Formula Abarth? After insulting anyone in the room that might own a Fiat 500, I promptly opted for the single-seater, at Imola.

After a brief (rather impressively so) loading sequence, the car was dropped on the track, and immediately the rawness of this pre-alpha version of the sim was apparent. Modifications to the seat position and controller configuration had to be done via a ‘console’ within the sim, similar to that seen in first-person-shooters, and the car was positioned on the startline, rather than in a pit garage. Clutch modelling had not been implemented yet, so it was just me and two pedals. I clonked the sequential shifter into first, and set forth on my way, the first-ever test-drive of Assetto Corsa.

Gingerly arriving at Traguardo, the first thing to hit me was the solidity of the steering, the firmness of grip that feels so ‘connected’. There is no discernible controller lag and the force feedback presents the firm feel of a tyre contact patch reacting to the change of direction cleanly and decisively. This firm feedback gives me confidence, and I try to up the speed. Then, at Acque Minerali (named for a botanical park in nearby Bologna, and not Italian for mineral water as is commonly, and incorrectly, inferred), I fly into the gravel. My first experience with the Fanatec Clubsport pedals is granting me the first chance to try a load-cell brake pedal, and being used to a standard spring-based system (albeit a firm spring on my BRD Speed 7s at home), I was not hitting the pedal hard enough. Ok, something else to think about; ‘act like its real life’I tell myself as I scramble out of the gravel in front of my expectant crowd.

In these early stages, there is no damage turned on in the sim, which is a godsend as I take a few laps to get used to the feel of the load-cell brake pedal. When I start to arrive at corners at the right speed and push a little with the car, I find a trance-like feeling taking me over as I start to process the way this car works. The steering feedback is simply stunning; under hard braking, the car jiggles and squirms in a very natural way, but not in such a way as to be unpredictable. The planted feel of the car keeps surprising me as I come to expect ‘sim-like’ motions or snap oversteer on braking or heavy throttle. The car behaves, full stop. It is a racing car and should not be sliding and flying about the place, and this is what happens. The Formula Abarth has more downforce than it does power, and this shows. Admittedly, the early setup is understeery, not unlike what you might expect on a real car, and this means in the faster turns the back end stays well planted on heavier throttle and can be driven hard without necessarily kicking back. It takes me some laps to trust in this—many sims over the years have taught me to be wary of a sim-car’s behaviour, never quite trusting in the early laps what the back end might do. For AC, I had to train myself out of this behaviour, until you really start pushing; it is not tricky to keep the car on the track.

The feel of the contact patch on the front tyres, directly through the steering, became my opiate as I built up more and more speed with this little gem of a single-seater. Feeling the front tyre slip through my hands becoming more and more natural, I could easily initiate understeer by breaking the traction with a heavy steering input, then bring it back by releasing lock on the wheel, no hunting for grip, it could be felt directly through the wheel-rim, making small corrections to trajectory feel intuitive. In fact, they are so intuitive they are barely ‘felt’ at all, they just happen!

What this gives the driver is a remarkable feel for the car on entry, the weighting of the front tyres under brakes, the yaw on turn in, and deftness on controlling longitudinal weight transfer. Understeering towards the apex at Tosa or lasering into Piratella at high speed, with each passing lap this sim feels more and more glorious.

As Marco proceeds to post a few pictures to Facebook of my ‘concentrating face’, I decide to try something else. Slipping neatly into the P4/5 Competizione, a race-prepared and heavily modified Ferrari 430 in GT3 spec, and much heavier than the Abarth, I do so anticipating that it will feel quite different from the driver’s seat.

The same, clean, decisive feedback could be felt instantly in the P4/5, but the weight of the car meant a tidier hand needed to be applied on entries, and care taken not to overwhelm the chassis. Again, the load cell caused me problems, the extra weight of the car needing and even harder stamp on the pedal, especially as I took the car to Monza, where there are some seriously big stops. Starting to push in the P4/5, there was a clear feeling of much more weight in the car, and with it the added respect you have to give the controls. Smoothness was rewarded, and driving it like a Formula Abarth in the early laps mainly led to me having big slides on entry through being too aggressive with the steering. As I began to settle down and let the car have its head, rather than wrestle it, that trance started to come back, and the feel from the car began to become more and more intuitive. Provided I could get it stopped in time! The chassis would soak up kerbs with minimal fuss and started to feel like a very nice drive, if far more serene than the Formula Abarth. Pushing more and more made the car bite back, and sometimes quite hard. But a smooth hand on the steering wheel ensured no big surprises, and as the laps ticked away, I started to get a great feel for the slip of the front and rear tyres, diving deep on brakes into Parabolica, then hard on the throttle, no surprises, and gently drifting to the outside edge of the circuit for a full speed drag to the Variante del Rettifilo.

It was time for the big one—the vintage single seater. AKA the legendary Lotus 49.

The Lotus 49 seems to be making a major comeback in sim-racing recently (iRacing, rFactor2, and pCARS). Boasting 410BHP and weighing in at 600KG, I actually sense a mild trepidation when selecting this car; whilst everything so far has felt natural enough to drive for me, they all bear relation to cars I have driven in real life. This is a step beyond.

I take it to Monza figuring there are less corners to kill myself on.

Initially it feels … fine. Very stable, connected to the road and manageable. A reasonable foot on the throttle keeps the back-end in check, and once the speed loads up, you can be fairly heavy with the throttle and not expect wild, lurid slides. This is more like it. And the sound, woah, it sounds tremendous, the induction note on throttle so throaty and full of beef, while the off throttle wheeze makes me grin uncontrollably. I turn to Aris: ‘This is great!’

Again, the car is setup for understeer, and you can feel it through Curva Grande as the fronts scrub. But instead of ploughing off the circuit, the tyre model responds more deftly. Break of peak grip does not mean no grip, and so when the fronts break traction, they drag at the nose and skip over the track, slowing the car all the time. Let off a little and let the front grip come back in, and she responds, the steering comes back, and once again that glorious force feedback let’s me feel the grip available as I start to push on with this fine motor car. Maintaining a healthy fear on the throttle on exits, I keep hearing Aris in my ear saying, ‘give it more throttle, go on.’ But with limited laps, whilst I started to get a feel for the way this car can be driven on the throttle, it will take many more for my confidence to build to really get to grips with the vehicle. Aris duly leaps into the seat and shows me how it is done, driving the car confidently on the throttle, braking deep and letting the car yaw mildly, then getting on the right-hand pedal and deftly controlling the oversteer.

The feeling I get from AC is that each car is a very, very detailed model, and as such, one learns more and more about the machine with each passing lap. Cars like the Lotus 49 could bring surprises even after 2000KMs of running, the depth of the simulation is so remarkable that I get the feeling this could steal a lot of my time, even before any AI or online racing comes into it. Curiously, though, this is not through having to learn to drive the sim. The cars feel stable and usable easily at lower speeds, as they should. No one flies off the road in the pitlane in normal conditions, and most of us manage to drive a car from place to place on the road without having big slides or end-over-end crashes. But when you start to push in AC, the feedback from the car takes you in, and as you find yourself braking deeper and deeper into Rivazza, you gain a flush of endorphins as the car hooks into the apex. Getting it right and being quick is a challenge, but not an impossible one—the car is never unpredictable in its responses, it behaves itself, provided its driver does.

Most of my early ‘moments’ with AC saw me driving it as if it were a ‘sim’ and not like a ‘car’.  A curious response, but over years of sim-racing, we build pathways in our brain that tell us what a virtual car will do in given situations, and it hasn’t always been the same as a real car, even in the best sims on the market. AC requires you to train your brain out of this, and look at your own performance as a driver to analyse what could be causing the car to behave certain ways. As I found more and more pace in the Formula Abarth, after lunch and espresso, I started to recognise problems with my driving that were causing me to lose speed, and they were the same problems that affect my real life performance. My style translated across and, well, rather annoyingly, I developed the same habits that cause me to not always find the sharp end in real life racing. My tidy, smooth inputs in high speed stuff reflected in a glorious feeling through Piratella. But my tendency to overwhelm front grip and take more than one ‘bite’ at a corner in the slower stuff blighted me through Acque Minerali. I had to sit back and tell myself those fateful words that Alonso said to Massa at the Nürburgring in 2007: ‘You need to learn!’

Stepping out into the Mediterranean sun for lunch, I began to enthuse gently (whilst keeping my cool, you understand!) with Aris, but the information was still setting it, slowly, about this sim and what I had just tried out. Things were coming to me as I ate my Pappardelle at the Ristorante da Righetto (con ragu di cinghiale o di lepre, and yes, it was delightful, and yes, it was the boar not the hare), things kept coming to me as we drove back to the airport, and the damn thing was still stuck in my head when I was finally walking back through the door at 23.30 that evening.

Assetto Corsa, at this early stage, feels superb to drive, and the team admit that this was their first mission. The potential in, what is, a very early alpha of the software, is remarkable, and truly reflects to me the next generation of racing simulators that will come our way. There is a long way to go, and potential for this sim to get even better. As it stands, the laser scanned tracks in full DX11 glory look stunning, and run smoothly on hardware that is far from top-end. The driving experience, for me, represents the beginnings of a sim that could go on to great things. For now, we must all sit back and wait, and watch those tantilising shots appear on the AC facebook page as the weeks tick by. For me, it will be even more difficult as I contemplate that hot Italian summer and the warm Autumn until finally I will be able to embrace it again …

 

The original Ferrari Virtual Academy (FVA) was a curious sim. Perhaps not really wanting to compete with the mainstream market, Ferrari opted to join forces with Kunos Simulazioni to create a special little nugget of racing-sim memorabilia that people almost definitely wouldn’t be playing for years to come. And so to prove me right, they decided to offer us with a seasonal update, the so-called Adrenaline Pack.

What FVA’s Adrenaline Pack gives us is a chance to drive this year’s Ferrari F1 car, the F150th, bolting onto the 2010 version of FVA which gave us the far more competitive F60. Both cars are meticulously realised, both in sim terms and graphical terms, and can be driven across three laser-scanned circuits (depending on which tracks you shelled out for): Fiorano, Mugello, and the Nürburgring GP. Laptimes, as before, will be uploaded to a central server at Ferrari.com for entry into a competition that will give the winners all manner of things and stuff. This package also includes a more ‘normal’ car in the form of the Ferrari 458 Trofeo Cup, which will appeal to many as a more drivable vehicle. Whether the contest is important to you or not, the important thing to note here is that this sim, whilst derived from the very capable physics engine used in netKarPro V1.3, is a hotlap sim. There is no racing, no wheel-to-wheel, just you, the cars, and the tracks.

For some people this will be an immediate switch off, as there is limited appeal to running around a track on your own, and if you are ‘most people’, and have been driving racing sims long enough, you will know you are not fast enough to set the fastest lap of anyone the world over. Yes, you. So why buy this sim? A good question. The marketing decision not to include an option to race any of the cars on the beautifully realised tracks in the package makes little sense to me, and what will limit long-term interest even more is that each comes with a fixed setup, so even the tinkerers amongst us will not be sated.

For me, this sim represents the peak of what the netKarPro engine is capable of. F1 cars present a unique problem for sim developers: they are exceptionally fast, with minimal suspension movement, and very high torsional stiffness and that all combines to produce a large focus onto the tyres. Thus, any car this fast and stiff will highlight any problems with the tyre model. The tyre model in netKarPro is widely regarded as one of, if not the best, tyre model available commercially. So, the chance to drive such a gem is a feast for the senses; not only is this the first time a high performance, GT-class supercar has been modelled in this engine, but also the differing F1 cars, from 2010 and 2011 respectively, are showcasing very different tyres (Bridgestone and Pirelli respectively).

As many of you will know, the change from Bridgestone in 2010 to Pirelli in 2011 has been the talking point of the year in F1 circles, and FVA gives us the chance to feel that difference, with a sim that has been tested and approved by drivers such as Giancarlo Fisichella, Felipe Massa, and Fernando Alonso. So let’s go back a bit and rephrase what we said: Yes, this is just a hotlap sim. But it also happens to be a unique a chance to compare yourself against F1 drivers in one of the most accurate commercial simulators of this generation. So let’s get cracking.

First of all, I’d like to take the Ferrari 458 Trofeo Cup for a drive. This car, derived from the road-going version, is a stiffer, lighter race-bred GT car used in the European one-make ‘Ferrari Challenge’ series enjoyed by many a playboy. The car features a semi-automatic, seven-speed paddle-shift gearbox mated with a 4.5 litre V8 pushing out 562 horsepower.

Pulling onto the track, my first thought was how comfortable and easy to drive this car is for such weighty specifications. With traction control disabled, it is easy to get the tail wagging, but the torque curve, peaking at the top end of the rev’ range, means that a relatively gentle foot will see you right, and the deftness of the tyres’ slip curve allows supple manipulation on the limit. This starts to become a joy as laptimes start being ignored in favor of controlled four-wheel drifts; though overheating the rears can become an issue, the tyres seem to cool very quickly. This ‘feature’ of the sim is based on the hotlap nature, and there is no damage if you go off, and minimal tyre wear.

Nonetheless, the more I lapped in this car the more I liked it, and subsequently found myself running lap after lap until the fuel tank was dry.

As the laps drew on, it was interesting how the car developed for me. I jumped into the car at Mugello initially, and was instantly missing braking points, taking brakes too deep, and carrying too much speed into corners. This oddly let me learn quite a bit about the car as I started to get a much better feel for its front end. Too much speed into a turn would easily overload the fronts and foster an almost terminal understeer, but more precision, and getting the car slowed in time, allowed me to start slicing into apexes. This felt like the forward weight transfer was causing a heavy dive at the front, as may be seen in a softer road-going car, so the development of style to a more smooth entry yielded notable benefits in times.

This link to a road car feel reminded me of a drive I took in real life in a Ferrari 360 Modena a few years back; the suspension is compliant but usable, with the front tyres being easily overloaded by too much entry enthusiasm, the back-end getting wayward with a heavy right foot, but nothing resulting in anything too ‘uncatchable’. In the sim the tyres behave superbly as they break grip, and then the subsequent return to grip as the moment recovers feels precise and natural.

So after a few laps of understeering, I started to balance it properly on entry and not overload the fronts, getting smoother and smoother as I went, and before I knew it I was having the car moving around gently around me in a delightful way. The final corner at Mugello, indeed, started to become something of an adventure in controlled four wheel drifts. I can’t remember a sim where it felt so natural and easy to put a car into this condition and not fear that it would kamikaze into some insanely exaggerated oversteer moment; modulating the throttle and making sure the rears didn’t get too hot meant I could keep this up for lap-after-lap.

Under brakes, the 458 also feels absolutely superb. The way weight shifts on initial application, the way it feels as it squirms around, is well done, as it is in netkarPro V1.3, with the subtle touches of feedback through the steering wheel making for a clean and visceral experience. The only thing, and I will come back to it again, that took a while to adapt to in this car was judging turn-in grip levels, and how loaded the front tyres were, or whether indeed they were too overloaded and would not turn. This is something I find quite common in cars with power steering, as the steering does not weigh-up sufficiently to feel the amount of grip available. This is usually the hardest thing to judge in any car, as one usually finds out when one takes the first ‘bite’ at the wheel. However, the steering in this 458 does not give enough feedback for my liking, which may well be a complaint I would find in a real-world 458.

Upon investigation and discussion with the guys at KS, it seems that this ‘road car feel’ that the Ferrari 458 has in this sim is something of a limitation of the engine. With the 458 Trofeo Cup we have a car that can generate 1.6 of lateral g-forces, and yet the feel is one of a road car: It does not always feel well connected to the road, and at times feels a bit ‘floaty’.

Trying to balance the car between the setup and physics point of view was like lying in bed with a short blanket was how the KS team explained the process. You try to cover your head and your feet get uncovered, then you try to cover your feet and your chest gets uncovered. So when setting up the car, if you try to give it more front-end bite, you get too much oversteer, and vice versa. It’s hard to find a sweet spot because the tyres themselves are a little unstable.

This is not an issue on light single-seaters (the main cars that netKarPro evolved with as a sim), and you don’t feel it at all with the F1 cars in FVA. But as the weight and the inertia of the car rises, and the grip lowers, this issue surfaces, and the car can feel softer and less connected to the road than you would expect from a race car. This is not to say that the Ferrari 458 in FVA is not superb fun to drive, and would be a blast to race.

The KS team is all too aware of this limitation to the engine, and at present is moving forward with development of a completely new, ground-up rebuild of their physics engine to combat such problems. By focusing on the small details of the engine, one by one, and addressing them at the base, they are hoping for a far better feeling in future titles (and yes, some big ones are already being worked on). netKarPro, admittedly, had many problems, but the fundamental driving ‘feel’ remains its strong point. With their new project, KS are taking this aspect to a whole new level. By starting out making a light car with ‘road’ tyres that generate around 1 to 1.2 of lateral g-forces, and getting this right as a benchmark, is the first priority of KS moving forward. Once a low grip car, road car, feels connected, then anything else, moving up the scale of overall grip, becomes easier and will feel better.

On to the F1 cars, and time for a comparison. Anyone who drove last year’s FVA and the Ferrari F60 will have an idea how the car feels in this sim, and to my mind it remains the best example of a commercially available F1 simulator around. This physics engine feels made for this, and the nature of the experience in FVA closely approaches instinct as you push more and more in a car than can carry obscene amounts of speed through corner after corner. Catch a slide there, mount a kerb here, it feels like the link between you and the car is inseparable.

Where the two cars differ is in the tyres; the difference between the Bridgestones on the F60 and the Pirelli’s on the F150th makes for a surprisingly different driving experience.

The Bridgestones are precise, and favor a smooth style as the driver needs to gently load them up on entry, avoid carrying brakes too deep, and not overload the fronts as the turn-in phase becomes a tight-rope moment. As balance transfers to the rears on exit, it can similarly be easy to overload them and face a big drop off in grip as you power out of a turn. This all adds-up to lend the Bridgestone tyres toward a precise style, with clean, balanced turn-in and smooth throttle application.

The Pirellis, in stark contrast, feel overall lower in grip, and very ‘waxy’ on the limit as they respond better to being heavily loaded-up and considerably more forgiving when pushing outside the envelope. As a result, the driver can be much more aggressive with the Pirelli tyre, giving much firmer steering inputs as the tyre will take the ‘abuse’, though preferably via an earlier turn-in to allow for the lack of precision as the tyre loads up.

Getting speed out of the two differing tyres is achieved via distinctive ends, making for fascinating laps as you learn what works for the two tyres. Swapping between the two cars therefore becomes tricky quickly too as, whilst the vehicles themselves are not radically different, the rubber they are wearing certainly is. The F60 requires a far gentler touch on the wheel than does the F150th, for which the same gentle touch is simply not aggressive enough to make the tyres perform; with not enough load, the Pirelli lacks grip. Comparatively, to be this heavy-handed in loading-up the tyres on the Bridgestone-shod F60, results only in the tyres being too heavily loaded too quickly and dropping off severely in grip.

From this, we can start not only to understand but to experience what we have heard from many F1 drivers concerning their tyres in the last couple of years. And this, really, is the best way to assess FVA: One of the best sims on the market for sheer driving, but with a lack of content and game modes, it has limited appeal. Driving for some fun laps for a while in each of the cars can be a worthwhile diversion, but I cannot see myself booting FVA up too often in a year’s time just to do some fun laps. It’s a shame in many ways, because if there was a relatively simple online racing component to this sim, it would become a long-lasting cult classic that could continue to have DLC added for years to come. Still, a better F1 racing sim doesn’t exist commercially, and if you’re at all curious to experience these ultimate machines, and don’t have a few million to buy a seat, this is as good a place as any to try them out. As it stands, this will remain as a shining diamond that never quite reached its full potential.

Stefano Casillo:  Hey, Jon.  If we have to do that thing today it has to be before Napoli’s match in the Champions League…

Jon Denton: Sorry, forgot to get in touch, I’ve been crazy today!

Stefano Casillo: It’s okay, we can reschedule.

Jon Denton: No, no. No, let’s start— so if I am correct, the first public release of a driving sim you made was netKar namie V0.9.4, right?

Stefano Casillo: namie was 0.9.9. Before that there were eight releases … long story …

Jon Denton: Did they all go public? I think the first one I drove was 0.9.8, at Newbury, there was a Formula Renault, Mini, and the Toyota Supra GT.

Stefano Casillo: That’s right, yes.  They all went public, the netKar free stuff is all from 2002 to 2003—I started work on them a few days after 9/11.

Jon Denton: Then 2005 was when we started talking about netKar Pro.

Stefano Casillo: No, April 2006.

Jon Denton: Yes, the public release was April ‘06.  We did a few interviews through 2005 for AutoSimSport and I got the beta from you in September 2005 for a test drive.  Then we did some online races with Marco (Massarutto) and Simone (Trevisiol).

Stefano Casillo: We announced it at the end of 2004, yes, that sounds about right

Jon Denton:  So at the time you worked for Quantel in the UK, a company that designs and manufactures digital production equipment for broadcast television and motion picture industries, based in Newbury, Berkshire.  What was it that made you start up the idea of a racing sim after 9/11?  Bored at work?

Stefano Casillo: No, not bored. I always had some kind of gaming project going in my own time.  A racing sim was one of the things I thought I could actually do from start to finish.

Jon Denton: I seem to remember you released a Tennis sim too?

Stefano Casillo: Yes, that was right before I started with netKar, I also made a space sim! Usually those are the sort of things I get into.  But the racing sim idea was cool because the simracing community at the time was awesome. I like unique things.

Jon Denton: So would you say you were, or maybe still are, a keen driver? At the time you had a new Mini?

Stefano Casillo: My Mini at the time was very a unique car on the road.  I was working as C++ developer in the UK which gave me pretty decent pay so I could afford it, sadly I didn’t have the time I would have liked to enjoy it.

Jon Denton: Did you ever think about going racing in cars?

 

Stefano Casillo: I never had the financial background to even get into karting. It’s not something that people in the south of Italy really do.

Jon Denton: Where are you from, exactly?

Stefano Casillo: Napoli. Which in English is Naples.

Jon Denton: My Italian teacher says that people from the south are very pessimistic, I’ll add that he is from Sicily!

Stefano Casillo: Nah, I don’t think pessimistic is the right word.  I would say people from the south tend to think about life as something that is already planned out in advance.  Of course, I don’t consider myself the typical man of the south, considering my history of constantly jumping into the unknown.

Jon Denton: You moved to the UK to pursue a career as a developer in C++; was there a plan to work for a large company, or did you have no plans when arriving here?

Stefano Casillo: I moved there because I got the job offer from Quantel.  It wasn’t a game company, which was what I had been looking for, but after visiting Newbury I loved the environment there. Coming from a messy noisy city like Napoli, it looked like a fairy tale town.

Jon Denton: Yes, very quiet and peaceful (This author lived in Newbury from 1990-2006.

Stefano Casillo: I would see lots of guys at lunch in the canteen, and they were not the twenty-something developers, in the job as a stepping stone to something better, they were experienced “grown-up” software engineers.  It felt like a good company to be in for a long time.

Jon Denton: But your real dream was to be in game development? Or, at the time, did you foresee growing old at Quantel?

Stefano Casillo: Yes it was my dream, but I felt I couldn’t get into it.  In Italy I was rejected after interviews with Milestone and Ubisoft.  I got very close to a job with ISI, but there is no real game development in Italy, and the stuff Quantel does is as cool as games.

Jon Denton: Yes, true.  Certainly from a technical point of view.  So, when you started to develop games in your spare time, did you ever think it would go anywhere, or was it just a hobby?  As in, was it a desire to find a way to a different career, to get noticed, or was it just an outlet?

Stefano Casillo: No, it was just for me really. I never thought it would end up the way it has ten years later.

Jon Denton: So you started to push your work out to the public: was netKar the first game you went public with, or did netTennis go online?

Stefano Casillo: The tennis game was, maybe still is, on sourceforge.net.  Open source was quite big at the time, 2001 was supposed to be the year of Linux on the desktop (this is an old joke that slashdot.org readers will understand), but there was no community for tennis games.

Jon Denton: Back then very few games had much community around them, online was a relatively new thing.

Stefano Casillo: For racing sims, Drivingitalia was huge. So it was very natural for me to get involved there, I was already part of that community as a gamer.

Jon Denton: Was DrivingItalia the birthplace of netKar, or did it go out on sourceforge too?

Stefano Casillo: netKar was only on DrivingItalia (DI). I never had the idea to go open source.

Jon Denton: As you said, you were around on DI for a while, were you racing online before netKar came along?

Stefano Casillo: Yes, with VROC a lot (For those not old enough to remember, Virtual Racers Online Connection, or VROC, was the third party application that allowed online internet racing to take place in Grand Prix Legends).

Jon Denton: So the first version went out, what was the initial reaction? And what did it entail in terms of cars and tracks and online?

Stefano Casillo: It was really nice. I think the first version had the Toyota Supra GT car and the original Newbury track which I modeled in 3D myself.  The reaction was immediately very positive. The original, free netKar’s development had been supported with positive karma from the community.

Jon Denton: Did Newbury have the racecourse building back then?

Stefano Casillo: Yes sort of! It had my house at the back of the last hairpin, too!

Jon Denton: Were there online leagues and sessions right away? I seem to remember most of the coverage on DI was in Italian back then, and there was no English forum, so the audience was mainly Italian I suppose?

Stefano Casillo: No, there was no multiplayer until version 0.9.9 of namie.  That is why namie is what most people know of nowadays.  But the history of that release is crazy; I hit the ‘compile’ button for the last time while a removal person was pulling out the plug of my PC because I was leaving my house to go to live in Tokyo.  I sent the build to Aristotelis Vasilakos and he had to sort out the mess and close a release that became 0.9.9 namie.

Jon Denton: Ah, so Aris coming back into Kunos again now is like competing the circle.

Stefano Casillo: Totally.

Jon Denton: The early days saw netKar as just a hotlapping sim—versions 0.1−0.8 I mean. How did you develop the tyre model and vehicle dynamics? Do you have a background in engineering, or was it a case reading lots of books?

Stefano Casillo: Lots of books. I lasted thirty days at university—schools are not for me.  It took me seven years to get out of highschool, instead of the standard five. I just couldn’t be bothered.

Jon Denton: So there must have been quite a deep interest in vehicle physics? Learning this stuff is no walk in the park. I presume you had followed F1 racing and motor sports for a long time?

Stefano Casillo: Yes, but most of all there I had a love for Dave Kaemmer’s work: From Indianapolis 500 to Grand Prix Legends — not to forget IndyCar Racing, one of the finest.

Jon Denton: And Geoff Crammond?

Stefano Casillo: Of course, him too. I remember trying REVS on my C64—‘wow you can spin!’

Jon Denton: I had it on BBC Micro. My Dad could never understand how I could spend so much time on it!

Stefano Casillo: I come from a family that had a passion for F1 and Ferrari.  On Sunday it was race day, early lunch and then watch the race.

Jon Denton: Good times, some things never change.

Stefano Casillo: I remember my parents didn’t have the courage to tell me Gilles was dead because I was crazy for him.

Jon Denton: I was a little too young to see much of Gilles.  Senna was my hero, sadly I watched him go.

Stefano Casillo: I remember: with time I stopped being a Ferrari fan, I could never bring myself to cheer for Schumacher.

Jon Denton: Yes, I have only recently, with Alonso, re-found a love for Ferrari.

Stefano Casillo: It was also because I loved Alesi—I loved Raikkonen, too.  I was in London when he won the title, it was amazing.

Jon Denton: Kimi was one of the biggest talents of the last decade.  Such a shame he gave up caring.

Stefano Casillo: Yes, so true, such a character, but my wife likes him too much, so I’m glad he’s not appearing on TV that often anymore!

Jon Denton: So as namie v0.9.9, the first online version of netKar, was sent out into the wild, you moved to Tokyo, was this work related, or life?

Stefano Casillo: Both, really. Such a big change has to be about life, but Quantel made it happen so it was the easy way in.

Jon Denton: You worked for them in Japan?

Stefano Casillo: Yes. They have offices in Tokyo, but they don’t do development there, so my job was quite different.

Jon Denton: Namie brought us a raft of new cars to try too; was this when it opened-up to a wider audience as well?

Stefano Casillo: I think so. There was a car for everybody.

Jon Denton: And the English forums opened at DI…

Stefano Casillo: Yes, and there were websites like RaceSimCentral (RSC – At the time run by Tim Wheatley) that always followed netKar.  I think, maybe, at that time RSC was the centre of the sim-racing community.  That and the West Brothers forums!

Jon Denton: West Forums in 2001 was big news! Yeah, and High Gear, back in the day.  I think that was where I heard of netKar originally.  Around the time everyone was looking for something other than GPL to drive. Viper Racing was fun but not really good enough.

Stefano Casillo: Yes, you’re right, High Gear was where I started out, and met some people that are still friends today, crazy to think of it now.  It’s a shame new sim drivers can’t experience the community feeling that was going on back then.

Jon Denton: It’s difficult to understand what has gone away really.  Those of us there in the beginning are all much older now.  Younger people have grown up with the internet. I seem to remember people’s online personas just had more respect for each other back then.  So was it all positive karma coming in, or was there much in the way of moaners?

Stefano Casillo: Feedback was always good with netKar namie. Of course people started to get sore at me because I had to disappear.

Jon Denton: The move to Tokyo halted development I assume.  We had namie for, what, four years before nKPro? What was going on during that time?

Stefano Casillo: Well, work in Tokyo was just too much to even consider having the time to develop netKar.  Then when we started work on netKar Pro, it took much-much longer than I expected to get it done.

Jon Denton: Were you still in Tokyo when you started work on Pro?

Stefano Casillo: No, I had moved back to Italy and started here.

Jon Denton:  Moving from bustling Tokyo to sleepy Trieste?

Stefano Casillo: Yes.

Jon Denton: A nice quiet town, miles to walk for bread. Must have been a big change from the madness of Tokyo?

Stefano Casillo: Absolutely!  And I was really living in the middle of nowhere.  It was very, very hard to adapt to that lifestyle after the glamorous days in Tokyo, and that was a huge problem for the development of netKar Pro.

Jon Denton: How so? Surely software development likes quietness?

Stefano Casillo: Yes, but I kept thinking it was a mistake to leave Tokyo, and my job there, it got pretty dark and depressing at times.

Jon Denton: Did you know people in Trieste? Or was it a big step into solitude?

Stefano Casillo: I knew Alessandro Piemontesi, who was in the Kunos team by then and helped me to move.  He ended up leaving the team though, mostly because of my dark moods, and I lost many months in this constantly drunk state.

Jon Denton: You mentioned the team:  Who is the team? I know Marco Massarutto has been around through thick and thin, was he there at the beginning?

Stefano Casillo: Marco was the first person I asked to join the team when developing netKar Pro along with Alessandro and Aristotelis Vasilakos who also ended up leaving.  So we asked Simone Trevisiol to join, and the three of us have been pretty much the core.  Aris is back now, and we have more graphics guys around that we use, support, administration, etc.

Jon Denton: And who does what, broadly (I guess you all do a bit of everything to some extent)?

Stefano Casillo: It’s starting to resemble a software house these days, even if many of us are not physically in Rome.  Marco is mostly in contact with graphics artists, checking their work schedule, and making sure that we’ll have that track or that car ready for that deadline, and that it looks as our content should look.  Most of his work is hidden to netKarPro users at the moment, but he is Kunos Simulazioni for all our customers on the professional side. Simone is our track modeller guy, but he also modelled the Vintage for netKar Pro which is pretty good for a first time effort.

Jon Denton:  And he works in Vallelunga, too.  I guess the way technology is now, you don’t need to be in an office, unless you need to whip people!

Stefano Casillo: True. But face-to-face discussion is always clearest.  It’s so easy to get the wrong impression by using voice chat or, even worse, text chat.  Aris will now be in charge of car development, so basically I will sit on the beach and swim.

Jon Denton: It sounds good.  You have earned it!

Stefano Casillo: Not really, of course. I’ll have more time to code and fix bugs, and I can work harder and deeper on physics development because Aris will be able to put that work into effect on the cars.

Jon Denton: Okay, going back to the dark days of Trieste. When things started to lighten up, it was you, Marco, Alessandro, and Aris.  Then Simone came on board.  What was the thought process behind netKar Pro’s development? At the time the sim-racing market was still quite bereft of any ‘killer’ titles.  What did you want to achieve with it?

Stefano Casillo:  Alessandro and Aris left pretty early so it was me, Simone, and a guy who can’t be named.  The original plan was to take namie and make it into a solid sim.  Then we started what we call the ‘taliban process’ in which we tried to make the sim as realistic as possible, not only on the physics side, but also with respect to the entire approach to the product.  So in car HUD-style graphics were abolished—want to know your position in the race?  Learn to read the pit board when you pass.  Full mode was established, where repairs to the car after damage took time, setup adjustments too… What were we thinking?

Jon Denton: Well, you were thinking brilliantly! That giant pit board is still easier than a real one! But yes, the lack of an option to change it was maybe a little harsh.

Stefano Casillo:  Yes, but honestly, I enjoy racing online now.  I can see where my friends are, what lap times everybody is doing real-time, and so on.  As a developer we should try to bring the fun of racing to the PC, not just the frustrations of it.

Jon Denton: Maybe, but when I’ve raced in real life, I don’t have those things, I don’t have the time to think about that.  You know the car in front of you, and hopefully the one behind is too far back to see, but yes, you have a point there.  I am a bit fascist with these things though.

Stefano Casillo:  I understand you.

Jon Denton: So the plan was to go with ultra-realism, to push what had come before with GPL (Which also insisted on “pit board only” in car).  I guess around then we had GTR on the market from Simbin, too.  The main core of the community wanted realism, I think, back then: it wasn’t until they got it that they realised they didn’t like it!

Stefano Casillo:  The idea was that nothing could top netKar Pro—if you were serious about sim-racing, you would have to go to nKP, no compromises.

Jon Denton: How did you come to the decision to go down the single-seater-only route?

Stefano Casillo:  Differentiation, and the fact that you could stay true to reality without having to come up with a “Perrari G360”.  After all, the entire netKar Pro project was funded using my savings from Japan, so there was no money available for licenses.  During the last two weeks before we started the pre-order for netKar Pro I was also out of food.  Just plain rice for two weeks.  That’s living on a sim-racing project.

Jon Denton: And did you consider the “Perrari” or “Boyota Supra” option?

Stefano Casillo:  We had lots of harsh meetings about the Perrari option, yes.  Let’s say I won the argument, but history shows I was wrong because netKar sales went much better once cars like the Fiat 500 and the Vintage appeared, so if you’re doing a new sim, don’t rely on minor single-seaters.  I love single seaters, but many don’t. People seem to want something that handles more like a car they understand.

Jon Denton: This surprises me.  Some of the most popular cars in sim racing seem to be some of the most staid and dull road cars.  Not something that makes sense to me.

Stefano Casillo:  I love single-seaters.  The only car I really love in nKPro is the FF1800.

Jon Denton: The 1800 and the KS2, I love the KS2 so very much.

Stefano Casillo:  I think if you don’t have an F1 car, then any single-seater is seen as a surrogate of that.

Jon Denton: And if you do have an F1, it’s too hard to setup, and to drive at top pace for the majority of players.

Stefano Casillo:  Let’s just say it’s not very inspiring to drive.

Jon Denton: Was there any thought to go to F1, or to scale the single-seater ladder higher? Why was the Formula 3 car the top end?

Stefano Casillo:  We thought there would be more people who wanted to race cars like the F3 car because it’s a good car for online racing.  I always thought F1 is too extreme—even the KS2 for that matter—the speed deltas are just too high.

Jon Denton: Overtaking becomes very hard.

Stefano Casillo:  But you get addicted to the speed.  After working on Ferrari Virtual Academy, it was hard to go back driving the 500!  And that’s why we thought, let’s do the KS2 in netKar Pro.

Jon Denton: It’s true: I skipped from the KS2 to the F2000 over this weekend, and it was like going into slo-mo.  Tell me a bit about the tracks in netKar Pro.  How ‘designed’ were they?  All named after towns in Italy, of course—do you think they reflect the feel of the areas they represent, or were they names out of a hat?

Stefano Casillo:  They do, actually, some of them.  Aviano is a NATO base with F15’s and F16’s taking off, and it feels as if you’re flying a fighter jet somehow—it fits.

Jon Denton: It feels open yes, like an airfield circuit, the light feels that way.

Stefano Casillo:  Prato…  I have no idea why it’s called Prato …I think I was watching the news about Prato, and there you have it.  Aosta, well …what else? It’s in the Alps!

Jon Denton: I wish it was real and I could go there, it’s beautiful!  So getting back to namie—you started to adapt the engine, how much more advanced did things start to get?

Stefano Casillo:  Oh, how I wish I didn’t do it! But it’s too easy to say that now.  The major difference was the implementation of the shader technology.  Also, the entire car data structure changed—it went from a ‘code-driven’ approach in namie, where every car was a totally separated entity implemented into a .dll, to a more traditional data-driven approach where the code stays the same and the car is defined by a data file.

Jon Denton: The physics become more defined in a ‘world’, and the objects within it set their parameters?

Stefano Casillo:  Yes, and the process was better.  We started to have tools to implement tyres, car suspensions and so on.  Now people can see a small part of that with Koflite (netKar Pro’s track editor software), but the real netKar is all the other tools behind it that allow the physics level to be where we want them to be.

Jon Denton: The tyres developed so much further too.  Netkar Pro was the first sim to really give a feel of the lifecycle of the tyre, even visibly.  Were you working with tyre manufacturers to get the data for this, or was it based more on theory?

Stefano Casillo:  Tyre modelling is a constant process for me.  It’s very, very hard because even testing the real thing is hard to do.  NetKar Pro went through four tyre models in five years.

Jon Denton: Four tyre models before release?

Stefano Casillo:  No, four tyre models since the release: Verions 1.0 to 1.0.2 are based on a Pacejka model, 1.0.3 is based on a model called the ‘similarity model’, 1.1 is based on the brush model, and 1.2 is based on a new tyre model I was working on for, <ahem> a new piece of software and it was so good that I thought “I can’t keep this on my HD, this has to go in netKar straight away.”

Jon Denton:  I know Pacejka, and I have heard about brush, what is the similarity model?

Stefano Casillo: Similarity is a simplified Pacejka model developed by Hans Pacejka and Milliken.

Jon Denton: And the latest build does feel so very good, too, though it is surprising to hear this because the similarity between the models in different circumstances is quite remarkable.

Stefano Casillo:  Yes, there was one single change in the equation for the final version 1.3 that made it better; that was supposed to be our ‘next gen’ tyre model, now it’s gone so I have to come up with something ‘next next gen’!

Jon Denton:  There is always more to learn. As far as I can tell people are still learning when it comes to tyres in real life, let alone sims.  The early releases with Pacejka had well documented problems at very low speed, if I recall—I remember the early models felt very good in some situations and a bit strange in others.

Stefano Casillo:  Which is the nature of the beast if you work with a curve-fitting empirical model.

Jon Denton:  It breaks down the closer to zero you get?

Stefano Casillo:  Yes, because you always have the velocity appearing in something like X=Y/V so as V goes to zero. X goes to indefinite.

Jon Denton:  And the world implodes…

Stefano Casillo:  And people die and the ones who survive flame on the forums and ask PayPal for refunds!

Jon Denton:  So the brush model is used in a few other places I think. I did not know netKar Pro ever used it, I think we had an interview with the guys who did Virtual Grand Prix 3 telling us it was revolutionary: Amazing in the world of sim-racing quite how many things have been a revolution!

Stefano Casillo:  Differences are very subtle right now. I mean, think ten years ago, the difference between an arcade and a sim was huge: now you fire up Gran Turismo 5 and it feels very, very good.

Jon Denton:  So this development was to be a big step, but at which point did you put a cap on what you were doing? Surely you could go on forever, adding more and more features, or developing physics more and more and never release anything? It was mid-2005 when you let AUTOSIMSPORT have a go with a test mule-build, at Newbury with a carbon effect Formula Target car. How close was this to something you felt happy with? And presumably you had had other people try it out before that? Racing drivers? Or just close friends?

Stefano Casillo:  The driving experience in netKar Pro was always something all the guys felt very solid about: going from one tyre model to another just shows me that, at the end of the day, we’re not that far off.  Things don’t really change that much.  There are things in physics I keep coming back to; tyres and differentials are my favourite to work on when I have some time available, but lately I feel like I am pretty much exactly where I want it to be, so I end up experimenting with something different.  The first release of netKar Pro was so bad, bugs wise, because we didn’t have a real beta testing team.  Things got much better once we started working with Jaap Vagenvoort on the 1.0.3 release, and with the RSR guys for the latest releases.

Jon Denton:  Well, and me, Alex, and Bob for a short while! Was it just the three of you testing in the early releases then?

Stefano Casillo:  Yes, as crazy as it sounds, that was the case.

Jon Denton:  Only so many configurations or situations can come up.

Stefano Casillo:  I think we were very naïve in thinking: “well after all, it’s still netKar namie on steroids, and if it doesn’t work, people will support us as they did since back in 2002.”  That of course wasn’t the case…

Jon Denton:  I think the public suddenly changes their feelings on these things when you ask them to pay for something.

Stefano Casillo:  It’s true—and mostly right too, it was just a bit weird for us to become like Microsoft in a day!  Everybody hated us and wanted a piece of us.

Jon Denton: Yes, this was when suddenly it all changed for netKar didn’t it?

Continued in Part 2…