Piston Heads/Evo/Winding Road Articles

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Its rare when the team behind a sim get asked the sort of questions we would ask (i.e. the technical car focused ones), so this interview is great to see.

PistonHeads
PH - Why is Forza not available to play on PC as the sales would beat any Need for Speed game?
Dan - Forza Motorsport is highly optimized for the Xbox 360 architecture. Porting it over to PC would require a considerable amount of time and resources from the core team. Thus far, we’ve elected to apply our best and brightest towards innovating and incubating new experiences on the Xbox 360.


PH - What suspension kinematics do you have programmed in?
Dan - We’ve modelled the movement found in multi-link (double wishbone), McPherson, solid axle, and swing arm architectures. This has a big impact on how the tyre stays in contact with the road (and changes camber) as the car pitches and rolls. For Forza Motorsport 4, we took another look at how we had these suspension types mathematically modelled. We didn’t like the way the solid axle in particular was moving (one of the simplest architectures), so we took a car apart and studied the movement. After that, we figured we should reuse the measuring rig to better investigate a larger range of suspension types. This had a considerable impact on the perception of roll in both classic cars as well as the rest of the cars in the game.


PH - Is a live axle car really simulated with a live axle, is a McP strut really reacting like a McP?
Dan - Yes. But honestly, this isn’t the hardest math. Tire simulation is far more difficult and far more critical to making a good simulation. That’s why we’ve focused so much time and energy on improving our tyre simulation every release. The industry’s understanding of the science of tyres is advancing every year. Every year the tire manufacturers learn more. It’s not good enough to follow the text books regarding tyre models from two years ago. We want to use the data that will write the text books two years in the future.


PH - How much of car electronics are simulated? Ie, the McLaren MP4 12C brake steer? Do you program in a system similar in action to the real one with manufacturer feedback?
Dan - It’s a blend. Some proprietary systems are modelled with regards to torque vectoring. However, we’ve generalized the TCS, STM and ABS systems so that they can layer across all the cars in a consistent way.

PH - Or the F458 Italia e-diff, again, do you know how it reacts in different modes and copy it, or just make up what 'feels' ok?
Dan - As you know, the E-Diff does many things. It does torque vectoring as well as assist TCS and STM. It’s also highly proprietary. As mentioned before, we replicate some aspects of proprietary torque vectoring systems, but generalize TCS.

PH - Will we see the end of the 4WD dominance that plagued Forza 3?
Dan - Performance Index (PI) and car classification changed dramatically in Forza Motorsport 4. The AWD cars now generally scored higher. This means they have less headroom for upgrades before they are to the top of the class. Now, of course, we didn’t just add extra PI for AWD. We changed the simulation that drives PI. The two largest changes were:
1. We changed the PI sim track to include more complex corner types and some longer straights. One of the new corners in particular is increasing radius. This corner type naturally favours AWD cars-- as they can really apply their power as they unwind the steering and accelerate through the corner.

2. We changed the simulation code itself to more effectively use understeer on corner exit. This increased the exit speeds of the AWD cars in the PI simulation, therefore giving them a higher PI (and thus less headroom to the top of class). In short, we believe we’ve addressed the issue of AWD dominance at the top of each class.

PH - Tyre wear, will the tyres act in real time, or accelerated wear? Will it include marbles?
Dan - Tyres wear in real-time. Tyres heat in real-time. The tyre carcass flexes and heats up regionally. The tyre gasses heat up as a result of carcass heat and the gas pressure increases as a result of the gas heat. All of the systems are related. All of this data was brought in with all of the other data from our partnership with Pirelli. The tyre data in Forza Motorsport 4 is completely unadulterated. Pirelli performed custom tyre tests for us across hundreds of tyre combinations and conditions. They delivered reams of data and we changed our system so that it could be inserted directly into our simulation without any changes. This approach means that the tyre model in Forza 4 is the most cutting-edge available. Getting this level of partnership from a tyre manufacturer just isn’t possible most companies. This is the same approach that McLaren uses for the simulation they use to train their Formula 1 drivers.

PH - We know that a lot of effort goes in to simulate the varied range of cars in the game, but what about the tracks? One of the biggest differences for me is that some of the tracks have a static feel, there are bumps and ripples in certain tracks that do not appear in the game. What level of detail has gone into improving the tracks for Forza Motorsport 4 over Forza Motorsport 3?
Dan - The tracks have bumps and ripples. These were honed using the experience of professional race car drivers we bring into the studio. If you play Forza Motorsport 3 and watch the replays, you’ll see that there are lots of bumps. The biggest issue is that the suspension of the car absorbs the perception of bumps and ripples. In the real-world you feel the bumps. Some games increase the perception of the bumps by unrealistically adding huge (3+ inches or more) bumps where they don’t exist on the real track. That’s great for making hyper-action, but it isn’t our way.
For Forza Motorsport 4, we did two things:

1. We re-evaluated the different concrete and tarmac surface types on all of the tracks. We looked at the age of the surface and gave each of them a general smoothness score. This variety of surface types and corresponding scores translate into far more bumps and grooves than in Forza 3--but at realistic levels.

2. Of course, the car’s suspension still obfuscates much of the perception of these bumps, because our suspension modelling is realistic. So, we also added more player camera layers to help the bumps make it past the suspension and into the drivers view. This increases the perception of the bumps without sacrificing the simulation.

PH - On some of the cars I felt there wasn't a big difference in sound when upgrading the exhaust will Forza 4 be different?
Dan - We worked with many partners in the creation of Forza Motorsport 4. We partnered with TopGear to bring more levity and humor. We partnered with Pirelli to bring more accuracy to the simulation. We also partnered with Warner Brothers (in Hollywood) to help us get more impact out of our audio. In Forza Motorsport 3, we optimized the audio for 5.1 systems, but many players use their basic television speakers. In Forza 4, we have multiple mixes that are optimized for different speaker setup qualities.
It’s also worth noting that a petrol burning race car is so much louder than even a relatively loud production car. Furthermore, adding aftermarket parts like exhausts change not only the note, but the loudness of a car. However, your speakers are only turned up so loud based on your preference. We have to normalize volumes so that all cars can be heard, while still maintaining authenticity and impact. This means the mix has to be well-architected. This is what Hollywood does so well. We still use real samples to construct and position each car’s audio, but, thanks to our work with Warner Brothers, the mix has been designed to bring out the nuances from each car and its current state.

PH - Also when upgrading the cars will there be the choice of being able to put an engine from another manufacturer into a car e.g a LS3 into a Nissan etc ?
Dan - No. Unfortunately this isn’t possible due to licensing deals we have with our various manufacturing partners.
Source - http://www.pistonheads.com/news/default.asp?storyId=24511


Enjoy

Scaff
 
Very interesting. Nice to see a different set of questions than the standard ones most people ask.
 
BTW, they must have recorded that and then typed it out. No way would Dan spell "tire" as "tyre". I also noticed they used tyre and tire both in the same paragraph. Some interesting editing.
 
In a similar vein I found the following on the Evo website.

Evo
How Forza 4 made digital driving real

Forza 4 takes gaming up a gear with revolutionary, Hollywood-inspired graphics that deliver a game so real you can almost smell the alacantara leather. From the electrifying roster of over 500 glistening cars to the most exciting tracks from around the world, gamers and motorsport lovers will be stunned the blistering detail. Every arch, interior and apex has been meticulously rendered using ground-breaking graphics, ready for petrol or pixel heads to jump into the driving seat of the ultimate driving experience.

How the cars look so stunning
With a gleaming line-up of over 500 cars, ranging from the entertaining to the exotic, Forza 4 brings the most drool-worthy collection of metal ever seen in a game brought to lifelike detail thanks to a ground-breaking graphical technique called Image-Based Lighting. Used in Hollywood movies, the crack team at Turn10 take the light from the environment around the car and reflect it off the paintwork for an eye-popping, photo-realistic model that looks as glorious in AutoVista as it does screeching around Laguna Seca at dusk. The inspiring lighting and shading techniques allow rendered cars to take on real-world effects never seen before, and a gripping physics engine that uses real-world data combines for unparalleled realism. Using Kinect, you can get even closer to the rarest cars in the world: take the opportunity to check out the intricately replicated interior or press your face up to the paintwork and still see it in polygon-perfect detail.

Sound Recording techniques
Turn 10's attention to detail in Forza is fast becoming the stuff of legend, and so it is of no surprise to see its employees out doing themselves again with the lengths they will go to in ensuring accuracy within its new release. Take, for example, their approach to the sound recording. When driving real cars drivers are, of course, responding to effects of G forces and momentum in order to keep things tight. When playing a video game, by necessity sound replaces a lot of those signals, so it's vital it's done right. With that in mind, hundreds of cars have been brought into the company's garages and placed onto a dyno with highly sensitive microphones placed around it. Each one is then gunned hard, while the sound guys painstakingly endeavour to capture every bit of wheel spin and brake lock the cars kick out. That way, when you're at full throttle through the Bernese Alps and things start to get twitchy, you'll have what you need to stay in control.

Landscape
Regardless of how good the cars look, sound and feel, a true simulation game needs locations and tracks brimming with realism and integrity to be successful. Here Forza Motorsport 4 excels, and a wealth of tracks, both actual and fictional, have been replicated with minute attention to detail. All locations were visited by development team Turn 10, who took on average 10,000 photos at each venue, documenting everything from grandstands to scenery, and used GPS mapping to ensure tracks were replicated as accurately as currently possible. Pro racing drivers were then asked to drive the computerised courses, providing unique insight and perspective to each circuit, ensuring the greatest levels of realism from a racers view. A new graphics lighting engine has been developed with experts from animation studio Pixar to ensure Forza Motorsport 4 is one of the best looking racing games ever, while the all-new Autovista mode allows you to, with the help of Xbox Kinect, literally walk around, sit in and start up some of the most exotic cars in the world - and you even get Jeremy Clarkson of Top Gear giving his views on each machine.

Forza Motorsport 4 Tips
1. Over 500 cars to master on track 2. Profile Import lets people load up their profiles from Forza 3 3. Forza Motosport 4 features a host of official Top Gear content, including a chance to race the Star In a Reasonably Priced Car Kia round the shows test track 4. Autovista mode lets you use kinect to walk round, climb in and startup your favourite motors from the game 5. Halo's Warthog makes a special appearance as an unlockable car 6. To ensure car handling is as real as possible, tire manufacturer Pirelli provided the developers with data from custom designed tests 7. Use Microsoft Kinect to steer the cars round your favourite courses 8. Developers of the game brought in graphics experts from Hollywood studios including Pixar to help boost the gamers visual experience

Q&A
We caught up with Forza 4's Game Director Dan Greenawalt to see what about the game has him most revved. There's huge excitement about the game's release, why does Forza capture people's imagination like this? I think Forza Motorsport 4 is about speaking not only to car lovers but gamers in general. We're trying to build a larger car community because at heart this is about car culture and how we bring people together. So while we do great things with racing simulation and graphics, we also do amazing things with community. What's the most extreme detail you went to in order to ensure accuracy? It's kind of across the board, but the way we treat the tracks and having race car drivers come in, those are the sort of things that 0.01 percent of our drivers would ever notice, because you have to have driven the track, not just at speed, but in anger, to even notice that. This is the first time you've used Kinect, what sort of things can you do with it? Auto Vista, where you can walk around the car, open up doors and hear witty comments from Jeremy Clarkson. Head Tracking, where you can move your head to the edges of the screen, look through the apex and power through. There's Kinect Voice, which allows you to navigate the entire UI just using your voice. And then we have Kinect Driving, where you put your hands at ten and two, and that's about sitting down with your kids or your mates and just having fun. What Easter Eggs have you got hidden for us in the game? First off, Profile Import. If you've played a lot of Forza Motorsport 3, when you start the new game we gift cars into your garage based on what level you were at, as well as certain cars that we've been keeping under wraps. But the even cooler secrets are in Auto Vista mode. Here, you have to unlock cars by doing challenges with them and if you unlock half of the cars, you get a special secret car. If you unlock them all, you unlock the Warthog from Halo 4. Tell us a couple of your favourite features. Rivals mode, lets you play with the Kia Cee'd on the Top Gear test track - the Star in a Reasonably Priced Car. If you beat my time I can challenge you back and that, on our team, has been wildly addictive. And, of course, we have Top Gear integration throughout the game, with Top Gear Car Football, where you get people playing in teams where the defender is a Q5 and the midfield are Evos and then the front line are Ferrari's and they're all painted by a great painter - it's not only about racing, it's about cars and the painting and it just brings the car culture together nicely.
http://www.evo.co.uk/forza4/


Evo
Virtual Reality

Realism has reached new levels in Forza Motorsport 4, but is the virtual M5 actually like driving the real thing?

No one likes a smart-arse, but it is immensely satisfying to sit in front of a near-finished version of the exceedingly clever Forza Motorsport 4 and, finally, to spot a mistake. For ten minutes I'd been gawping at the new BMW M5 on a 60in plasma screen. It was the best view I'd yet had of the new supersaloon because a knackered foot meant I couldn't see it in the raw at the Frankfurt motor show the previous week. The rendering was perfect, and as Freddy the videographer's detailed (and indecipherable) explanation of the 3D modelling engine used to create such a spookily accurate unreality wafted around the room, all I could think was 'I'm going to spot the mistake, and enjoy telling them.'

The offending mistake didn't come through the visuals, because they are, it has to be said, annoyingly perfect: instead it came in the noise. As I waited on the start-line, blipping the throttle to try and launch BMW's 552bhp monster with maximum efficiency, I thought: 'This car doesn't sound right. They've mixed a Veyron and an Impreza together. I've driven a development M5, and it didn't sound like this.'

Smug interventions are best delivered after the event, so I intended to send the Microsoft team a cheeky note the following week, after I had confirmed my findings. Because the day after driving the M5 in Forza 4 in Reading, I was driving the real thing in Spain. This allowed me to clear my mind of self-important announcements, and settle-in and enjoy the Nürburgring Grand Prix Circuit in a new M5. If you had told me that my first experience of BMW M's latest attempt to catapault five people at the horizon would be through a wireless controller, an Xbox 360 and a big telly, I would have replied with a single, raised digit.

I have an unhealthy knowledge of the new, short Nürburgring circuit. To the point that I can recall the surrounding features and topography with an accuracy that would convince my racing teammates that I prefer sightseeing to motor racing. Virtual reality mimics real life in new ways on Forza 4: I'm so busy gushing about the crispness of the writing on the famous BMW over-track banner that reads 'Freude am Fahren' to anyone who will listen, that I miss the green light and lose five seconds. Drat.

The M5 has traction issues on Forza 4: with ESP and traction-control disabled, its rendered 552bhp - perhaps unsurprisingly - makes mincemeat of the rear tyres. Oversteer, meanwhile, is never more than a flick-of-the-thumb- away. The track modelling - in particular areas with tricky negative cambers - are accurately represented. Where local knowledge tells you the M5 will run wide, the M5 runs wide. I take this knowledge with me to Spain. As you'll have read, the new M5 does things other cars cannot. It isn't perfect, but then that is part of its charm. Many of those faults come as a result of the car's weight. On the circuit, in the flesh, it feels big and heavy, just as it does on Forza 4 - if you don't believe me, play the game and you'll know exactly what I mean.

What's more, try and complete three laps of a fast circuit without melting the brakes on the material object and your research will lead you to the same conclusion as me: Forza 4 has the M5's brakes down to a tee.

And the noise? My notebook details the following on the subject of the M5's vocal qualities: 'Sounds like a Veyron crossed with an Impreza.' Seems BMW hadn't finalised the noise characteristics when I drove that prototype in March. Forza 4 was right; I was wrong. Very glad I never sent that smug email.
http://www.evo.co.uk/forza4/article2.php


Evo
DRIVING FORCE

Just how accurately can Forza 4 replicate the character and handling traits of a car like the Subaru WRX STi?

It's actually a struggle to begin playing Forza Motorsport 4. Not on account of any menu-based confusion, but because the digital rendering sof the cars that populate the introductory screens, as the game loads, are so spellbinding in their crispness and accuracy that you lose yourself for a few minutes and stare as the camera pansaround the steroidal front arches of the latest Subaru WRX STi. Surely it's an HD video? You sit, mesmerised by the quality.

Forza 4 closes the tangible differences between real and digital to a point at which the naked eye struggles to decipher what is metal and what is rendered. Perhaps even more impressive is the fact that the same attention to accuracy present in the obsessive details of these renderings - the way the light swoops and pings from the WRX's mixture of soft shapes and sudden geometric outcrops - is also present in the driving dynamics of the cars themselves. Choose an WRX STi, and you are delivered not only that car's accurate form, but precisely the way it drives as well.

Really? I mean can you really glean any meaningful similarities between a computer game and a car with 297bhp? Given that all F1 teams now consider the simulator to be the most important development tool during the F1 season, it would seem that we need to keep an open mind on the subject. And an open wallet. The WRX STi, on a Welsh B-road, likes a drink. These latest 2.5-litreboxermotorsarequitedifferent in character to the McRae-era versions. Equal length intakes make them much smoother, less burbly and lumpy. Of course some of the character has been lost, but the upside is gratifying mechanical smoothness and a very particular sound: one that is uncannily replicated in the game.

Not being entirely sure how to conduct a test between something belonging to the material world and something which doesn't, I have settled on a simple plan. Accurately define how the, er, real WRX drives - what its basic characteristics are interms of power delivery and chassis response, and also what specific control inputs those behaviours require from the driver. Then go back to Forza 4 and seeif the same inputs generate the same response from the vehicle. Which isn't real. But which looks more real than the real thing. Think I might need a re-boot myself once this is finished.

The WRX is a front-engined, four- wheel-drive saloon car according, in the most part, to the traditional fast-Scooby script. The car has masses of mechanical grip, but it does want to understeer at all speeds. The only exception here on the latest version is that the car is more responsive to big throttle inputs early in a turn, and will throw more torque to the rear wheel than before. In short, it's a WRX that feels a bit like a Mitsubishi Evo. Unusually for a turbo flat-four, it's much happier to rev than expected, but it still suffers that frustrating torque-hole below 2500rpm. You have to keep it spinning above 3500 to feel even remotely bullish - the way nearly 300bhp should make you feel - and then between 4500 and 6000rpm the thing really flies. Relaxing, it is not.

It encourages a pretty brutal driving style - pushing into a turn with as much speed as the tyre grip will allow, then punching the throttle to take advantage of th ecar's new-found propensity to at least try to oversteer. The result is a kind of four-wheel drift as you exit a turn,but one you rarely have to correct with any steering lock.

Foolishly, back at Microsoft HQ , playing Forza 4, I don't give the WRX enough revs off the line and, just like the version that requires petrol, it bogs down. I should be celebrating this perfect demonstration of the simulator's art, but am instead livid at having been dusted by the entire grid. Chasing the fast-disappearing backsides of my competitors, and a little distracted by the level of detail in the background scenery (is that a wooden hut up there?) on the Alps Circuit, I pile into Turn 1 way too fast. In true WRX style, the front axle refuses to hit the apex, so I slow the car as fast as possible and then attempt to turn again. We don't crash; but we do learn that the circle-of-friction is rigorously obeyed on Forza 4: a hard-braking tyre cannot change direction at the same time.

The distractions continue: light pings from the snowy hills around the Impreza as it warbles up through each gear. Watch the rev-counter needle and in 2nd and 3rd gears it moves a little quicker between 4500rpm and 6000rpm, just like the street car. Into a tight second-gear turn, the entry speed is more reasonable, the car sweeps in, flat-on-the-gas and the understeer disappears and you enjoy that samefleetingsensationof allfourwheels dragging, not pushing, but hauling you from the apex.

It's hard not to get carried away with this cod-reality; it's infectious because its accuracy panders to the need in allof us to explore areas of dynamics otherwise denied by factors such as cost and lack of skill. Or wanting to stay alive. By way of example: we all know a Scooby deliberately tormented with a trailing throttle will pull big drifts, and you will be glad to hear that the same is true in the parallel universe of the Alps Circuit on Forza 4.

The only difference is that you will not attract the attention of the law, or enrich the owner of your local body-shop. Is it accurate? Yes, dangerously so.
http://www.evo.co.uk/forza4/article3.php


For videos follow the links.


Scaff
 
Love EVO, and C.H., I just do not like it when they use a controller to judge the realism of a game.

Thanks Scaff.
 
New one - Winding Road this time:

http://www.windingroad.com/articles...email&utm_source=email-247&utm_content=WR75+2

The main bit:

Winding Road
Now that we’ve covered the initial bases, let’s get into the nitty gritty of what is a very good racing game. Let us first note that we were racing with all the assists turned off, full damage rendering (cosmetic and mechanical), a manual transmission, and simulation steering (yes, we are nerds). Players of Forza 3 (your author included) may have noted that games sometimes offer questionable physics when it comes to tire grip and body movement. Sometimes, things just don’t add up. That is just not the case here. For all the ballyhooing about the physics engine in Gran Turismo5, Forza absolutely blows it out of the water. Everything about the way these cars behave is more lifelike than any consumer-level video game before it.

In engineering the tire qualities, Turn 10 Studios brought in Pirelli (yes, the same folks that make the rubber for Sebastian, Jenson, and Fernando) to help tweak how the tires react, grip, and behave through a variety of driving conditions. The result is, in a word, epic. Grip levels and the progressive loss of grip mimic actual rubber very closely. You can actually feel the grip wear out as you push the car through a turn. There is an extremely high level of progression in the way the tires wear and behave.

The same goes with the steering movements. We were racing with the standard XBox controller, so no fancy wheel here, yet the amount of feedback was excellent. With the simulation steering, it turns off a variety of the hardwired assists that made it so easy to drift cars and chuck them about in the last game. The inputs that you give the stick have a much more real effect on the way the car moves. Slide it gently to one side, and the car will be fine. Smash it to one side, and the car will violently jerk, much like yanking the steering wheel in real life. It is stunningly real, and presents a real challenge, demanding smooth driving in all circumstances.

The actual process of racing is remarkable for a few reasons. The AI is surprisingly well done. You’ll see AI cars dicing it out in front and behind you; it doesn’t feel like you’re on one side, and seven AI cars on the other. And those seven AI cars don’t drive around the track locked on their line like slot cars. You can actually watch the AI cars adjust their line as you drive around the track.

And when you do inevitably crash into those AI cars, it looks and feels and sounds real. There isn’t just some generic thud as you bump fenders. There’s grinding, scratching, rubbing, and the sound of broken glass with each collision. Granted there is some silliness, such as a firm bump scratching the paint across your entire front end, but all told, the damage rendering is top notch. One of the coolest bits comes when you smash very hard into something. Part of the screen goes white, and its almost like your driver is stunned by the impact. It takes a second for things to come back into focus, before you can start racing again.

The cars, of course, look beautiful. Inside and out, each cars is gorgeously rendered in very high detail. The highlight, though, is the sound. These cars sound remarkable true to life. We tested a few virtual cars that we’d recently driven in real life, and came away impressed with just how close these digital copies were in the acoustics department. Throwing a sport exhaust and intake on makes a noticeable difference as well, and gives many of the cars a very serious auditory bite.

Not all is well, though, as Forza 4 does have some things that we don’t like. For a start, we’d like to see a bit more track variety. Yes, there are over 20 locations, with each boasting a variety of different tracks, but somehow it isn’t enough. We like the inclusion of Infineon and the Indianapolis Motor Speedway, but some more real-world tracks would be nice. Think Spa, Daytona, and Fuji. It’s also high time Turn 10 Studios brought in time-of-day and weather variability. We want to race in the wet, and we want to race in the dark. Both of these can be done in Gran Turismo 5, but not Forza. These are small quibbles though, especially considering just how good Forza 4 is.

Where Forza Motorsport 3 was merely a solid competitor for the Gran Turismo series, Forza 4 absolutely dominates, offering a more realistic, intense, and fun racing product that is accessible by both hardcore drivers and casual fans alike. It may not be enough to throw away your PS3, but if you happen to already own an XBox 360 and enjoy a bit of racing, then Forza Motorsport 4 needs to be a part of your collection. You won’t be disappointed.



Scaff
 
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