How a car is made...

[kdryan]

So with everyone complaining about how older cars should have rims, PD should make more cars, this car sucks, etc. I figured you all might like to know what goes into modeling a car. Keep in mind, I am not an expert in this and am no where on the level of the guys at PD, but I do have a basic knowledge and have done a bit of it, even having one of my models used in a documentary for PBS. I am NOT a pro by any means and if anyone wants to correct me, please feel free, as it's been a while since I did this.


The Programs

There are basically two programs out there that the pros use to model. One is 3ds Max, which is better at modeling mechanical, architectural, etc. and Maya which is better for modeling photoreal figures, faces, characters, and what not. You can do either with both and do them well, but that's how it works out. They are both owned by Autodesk. A lot of artists will use a program called Poser that creates and does basic animations for figures then port them into Max or Maya for detailing and animation. There are about a million other smaller graphics programs to work with, but these two are the three hundred pound gorillas. Textures are generally done in Photoshop.


Modeling the Vehicle

The Mesh of the vehicle is basically made up of thousands of point called vertices (singular is vertex). 3 of these vertices form a triangle and two or more triangles together form a polygon. It is these polygons that form the surface of what you are looking at. When you look at the wheel well of the '65 Shelby GT350 and see that instead of a nice smooth curve, there is an arch of about eight straight lines, you are looking at the edges of the polygons.

Here is a sample of a wire mesh from a plane I worked on. One thing that needs to be pointed out is that while a polygon is two or more triangles, Max will not show it as triangles unless you tell it to, which is why you see squares and odd shaped polys.

The art of modeling the mesh comes from bullying vertices around the screen until you get a nice neat model like this:

Notice the drawings around the plane. These reference drawings are how the car is made. No magic, no smoke and mirrors, just forming the mesh to fit that image. A company may photograph the car and take hundreds of pictures of it, but your reference drawings ARE the model. Sometimes it gets complicated and very frustrating getting the mesh to do what you want, but that's the trick. Cutting the holes and keeping the mesh nice and smooth while keeping the number of polys down are the hard parts. Remember, every time you see that car, the PS3 has to draw EVERY SINGLE POLY! The plane in the second drawing has somewhere around 76,000 if I remember...

My explanation here is a bit simplistic, but you get the idea. Later tonight, I'll post about doing textures and why PD can't give you a livery editor for older cars...

Edit: I went back and checked. That plane has 116,000 polys. Keep in mind that is is drawn for use on a PC where more processing power is available. The GT3 cars may be significantly lower. I don't know...

 

[gogatrs]

Good idea posting this.
Thanks for explaining all that. I didn't realize just how much work it takes to convert a standard to a premium.
Do you know the difference in number of polygons is in premium vs. standard. GT5 vs. GT4 etc. etc.

Hopefully this doesn't get closed due to a bunch of haters.

 

[CarBastard]

As a "PD you need to work more! We need moaaarr cars!" idiot, I find this very interesting, and hopefully a lot of us will learn something to make our posts more educated 👍.

 

[GTShadowKing]

Wow friend thanks for posting this, now I can have an idea about the real differences between standart and premium cars, and how hard is to make them.
76000 polygons make that airplane real smooth, and GT5 premiums have 300000 polygons right? Awesome.
You sir desearve a 👍.

 

[kdryan]

GT5 Cars have 300k polys? Wow! Where'd you get that number at? That's a LOT of polys! I'm not saying you're wrong; I'm just surprised...

 

[GTShadowKing]

GT5 Cars have 300k polys? Wow! Where'd you get that number at? That's a LOT of polys! I'm not saying you're wrong; I'm just surprised...

I don't know mate I think I saw this somewhere...a long time ago. Problably I'm wrong, but the fact is that GT5 premium cars show the truly potencial of our PS3's

 

[GTShadowKing]

I just made a quick search and found this:
http://www.allagegaming.com/products/gran-turismo-5-playstation-3-review/
See "graphics" section, you will be like WTF?!

 

[DylanWhite]

Im a student at A.I. studying Game Art and Design.

Ive gotten flak for criticizing things about this game such as the trees, which are sometimes 2 polygons with an alpha mapped texture. Those are laughable at best and a huge eyesore. Anyone going into the industry knows that 3D artists are easy to come by. The guys at PD are great at modelling to next gen standards and anyone who has ever tried to model a vehicle to those standards will be amazed at how difficult it is. I attempted modelling a Porsche 550 and didn't like where I was with it and abandoned it. But then again I tried to do it in several weeks for a class assignment. Modelling is difficult to learn to do properly, but anyone can do it. I taught myself 3ds max in high school, joined a community mod project under Project Reality to donate a series of weapons all before graduation for a portfolio. What really takes talent these days is programming these things into the game and making them work properly. The programmers never get the credit they deserve.

Fun little visual aids:

A simple pistol like a USP .45 took me about an estimated 20-30 hours.



Compare that to the real deal:



Compare again to my competition:



As you can tell, the model is pretty accurate for a low poly object. The complexities of something small and machined is multiplied when trying to achieve similar levels of detail and polish on something larger that a player is interacting with and can get close to.

 

[Devedander]

Nice post but a few things to remember:

1 When it comes to any modern car, the original manfucturers CAD model probably exists and is easily accessible to be imported for everything from body panels to parts to trim.

2 While it's nice to sit back and have a "learn how hard it really is" lesson, the real measure is to look around and see how much is being done elseswhere... for instance it's quite hard to make a nice clay pot, but if pottery houses are routinely turning out hundreds a day, that difficulty doesn't somehow magically apply only to you as an excuse for low production.

3 http://www.exchange3d.com/index.php?searchStr=ferrari&act=doSearch (check the prices)

 

[MetroGS]

Good thread buddy! really interesting!! hopefully should cut out some of the haters hehe

 

[GeneralJesh]

Im a student at A.I. studying Game Art and Design.

Ive gotten flak for criticizing things about this game such as the trees, which are sometimes 2 polygons with an alpha mapped texture. Those are laughable at best and a huge eyesore. Anyone going into the industry knows that 3D artists are easy to come by. The guys at PD are great at modelling to next gen standards and anyone who has ever tried to model a vehicle to those standards will be amazed at how difficult it is. I attempted modelling a Porsche 550 and didn't like where I was with it and abandoned it. But then again I tried to do it in several weeks for a class assignment. Modelling is difficult to learn to do properly, but anyone can do it. I taught myself 3ds max in high school, joined a community mod project under Project Reality to donate a series of weapons all before graduation for a portfolio. What really takes talent these days is programming these things into the game and making them work properly. The programmers never get the credit they deserve.

Fun little visual aids:

A simple pistol like a USP .45 took me about an estimated 20-30 hours.



Compare that to the real deal:



Compare again to my competition:



As you can tell, the model is pretty accurate for a low poly object. The complexities of something small and machined is multiplied when trying to achieve similar levels of detail and polish on something larger that a player is interacting with and can get close to.

Nice post but a few things to remember:

1 When it comes to any modern car, the original manfucturers CAD model probably exists and is easily accessible to be imported for everything from body panels to parts to trim.

2 While it's nice to sit back and have a "learn how hard it really is" lesson, the real measure is to look around and see how much is being done elseswhere... for instance it's quite hard to make a nice clay pot, but if pottery houses are routinely turning out hundreds a day, that difficulty doesn't somehow magically apply only to you as an excuse for low production.

3 http://www.exchange3d.com/index.php?searchStr=ferrari&act=doSearch

/thread.

 

[parabulla]

Great post! Looking forward to your next edition.

 

[Milldrum]

My favorite color is green!

That's all I know about this stuff.

 

[DylanWhite]

Ryan, do you have a web portfolio or something? Just curious, kinda nice to meet people who have experience in 3D. Solid looking mesh, not going to lie. You have that thing rigged and textured?

 

[sesselpupser]

I kind of already know a bit about this (friends who use various 3D software for interior design, architecture and automotive design) so this isn't exactly news to me, but thanks for trying to educate people. However, and I say this as someone totally satisfied with GT5's car count and general standard of graphics, but saying 3D modelling is really difficult is fair enough, but PD are professionals. Milling engine blocks from aluminium billet is difficult, developing an F1 aero upgrade package in two weeks (or less) is difficult, flying planes is difficult, but that's why PD's modelling people get paid! If it were easy, then they'd pay unskilled workers peanuts, but it's not.

I'm sure PD keep their staff busy, I bet there's loads of stuff they've done that we'll never see; anyone remember the screenshots of a video showing a folder named 'Spa' (or something similar) on a PD computer? Or this FT86 II video, or the fact that the Nomad Diablo was in GT4 (or was it 3?) in Japan but not the US or EU. I personally work in (well, near) graphic design and I see so many portfolios with examples of advertising or packaging design which was pitched to a client but rejected; doesn't mean it's not still good design, right? I bet there's loads of cars in PD's network waiting for a license to be acquired so they can release them, or cars modelled as experiments, or cars that already exist which have been re-modelled, waiting for inclusion, which may never make it to GT5 because of PD's priorities and the fact that GT5 can't take up anyone's entire hard drive...

 

[DylanWhite]

lol, I did this for fun, someone got mad at me a while ago when I said it took 5 minutes to do trees this way. Took me less than 5 minutes, including the time it took to get a jpg from the internet. Alpha maps took less than 1 minute to make... arent they fun? Hey, PD, looking for artists?




EDIT:

Thats not the greatest freelancer example, but hey, at least the wheels are modeled as "wheels" and dont have flat faces on the inside. lmao

Not going to bother resizing in Imageshack.
http://cache.gawkerassets.com/assets/images/9/2010/12/eifelcircuit.jpeg

 

[IceMan PJN]

So with everyone complaining about how older cars should have rims, PD should make more cars, this car sucks, etc. I figured you all might like to know what goes into modeling a car.

What's your point behind this? Are you trying to impress people into giving PD a free pass to fall short of what other developers have done? Yes, there's more that goes into developing a car model than what most gamers realize, but that's not something that just PD has to contend with but rather faces every single game developer. Turn 10 had to deal with the exact same thing, and they had no problem producing 400+ Premium models for FM3. It still isn't an unrealistic expectation to want more Premium models for GT5.

Polyphony doesn't develop games in a vacuum. They're surrounded by other developers that deal with all the exact same issues and challenges. The intricacies of modeling aren't just an issue faced by PD but by every developer in the industry, no matter what game they're building, whether it's a complex polygon mesh for a car, for a face, for a horse, or whatever. If the guys next to them are producing larger volumes of content in less time, it's not unrealistic to ask for a bit more out of PD. Nobody has asked more of them than what has come from the doors of some of their competitors.

76000 polygons make that airplane real smooth, and GT5 premiums have 300000 polygons right?

Remember with polygons that the number there reflects only the number of polygons at any given instant. If a game is running at 60 FPS, then each polygon is rendered sixty times per second. So, 300,000 polygons per frame times sixty frames per second is 18 million per second. Also understand that those polygons aren't just the exterior of the car but also the interior, as well, all in one single figure.

GT5 Cars have 300k polys? Wow! Where'd you get that number at? That's a LOT of polys! I'm not saying you're wrong; I'm just surprised...

I'd actually expect nothing less from PS3/360. Going with my figure of 18 million polygons per second per car, multiply that by twelve cars at once and that's 216 million. I don't recall ever actually seeing official polygon figures for PS3/360, but that may be pretty accurate. That would be roughly in the ballpark of ten times what Xbox/GameCube could do a generation earlier.

I've seen figures floating around that suggest PS3 can do 275 million PPS, give or take, and that 360 can do around 500 million. I don't know where those figures come from, however, but my hypothetical figures fit into that just fine.

Good thread buddy! really interesting!! hopefully should cut out some of the haters hehe

How so? As I've discussed, complaints wanting more Premiums or about the crudity of Standards still remain valid. This thread hasn't given PD a get-by-with-less-free card.

 

[GTShadowKing]

GT5 premiums have 500000 polygons. It's in the link I posted above.

 

[kdryan]

Thanks for the feedback guys. Like I said, I'm not a pro, I've just screwed around in it a bit. Even that was a while ago, so I probably should brush up. That 500k figure surprises me; I didn't think a PS3 was that powerful. Then again, they're not multi-tasking like a PC is, so perhaps it's not so surprising after all.

I did the textures and rigging for a different version of that plane. You should see it later.

I never really meant to whine about how hard it was, but it's also not so simple to change 800+ legacy models. It's not just modeling the wheels, there are a lot of considerations and I find it hard to believe they started completely from scratch and were still able to import all of the cars from previous games. Modeling really is the easy part and probably takes less talent than anything else. I don't know what they're using for gauge technology, but I'm guessing it's XML based and I never could get that. Texturing takes some serious talent and while I got passable at it, I was nowhere near an artist.

If you really want to see some cutting edge CG stuff, then look here...

http://forums.cgsociety.org/forumdisplay.php?f=121

Actually, I think I'll hold off on texturing and animation because I don't know how they do it enough in GT5. I know how to do it for most other stuff, but I get the feeling there may be other things involved...

 

[DylanWhite]

Just post your theory in here, doesn't have to be right or wrong.

 

[Devedander]

Thats not the greatest freelancer example, but hey, at least the wheels are modeled as "wheels" and dont have flat faces on the inside. lmao

Not going to bother resizing in Imageshack.
http://cache.gawkerassets.com/assets/images/9/2010/12/eifelcircuit.jpeg

Oh know, the link was more to provide illustration you can buy quite decent models for $5-50... kind of puts things into perspective.

 

[DylanWhite]

Oh know, the link was more to provide illustration you can buy quite decent models for $5-50... kind of puts things into perspective.

Oh, I personally know all about that. Ive even considered selling my work as a student, could help pay for some things. haha

 

[kdryan]

Textures

Texturing (to me) is where the real talent lies in CG modeling. You can make a perfect model and make it move perfectly, but if you screw up texturing it, it will still look like crap and won't be believable.

Once you've gone far enough on the model, you open something in Max called the UVW editor. What it does is take the model you just spent weeks building and rip it a part for you. It flattens the model out, much in the manner of a map of the Earth flattened that looks like an orange peel. It does this one part at a time and is called a UVW Unrap. In this example the front wings and the fuselage were one piece, so the editor flattened it to look like this:

The top and bottom of the fuselage are folded up so you are looking at them as if flat. From this, a template is made and saved as a .jpg. The .jpg is opened in Photoshop and you begin painting your vehicle. In this case, a 1929 Travel Air Type-R racer.

After much editing in Photoshop and doing the same for every part (there are external programs that allow you to do multiple parts) you apply the texture map to the model by UVW mapping and end up with something like this:

Again, this is EXTREMELY simplified and doesn't take into account the massive amount of time and effort painting even a simple texture like this. The reason this makes it difficult to make new liveries is that the texture is mapped to every vertex if even 1 thing is changed on the model, the whole texture is going to be thrown off and have to be re-mapped from step 1. I don't know how Forza does it though, so take that as you will...

 

[DylanWhite]

I was taught a few different ways to unwrap objects, the easiest way being to use a 3rd party program called Headus UV Layout, importing 3d files as OBJs and unwrapping them super easily with stretching being auto corrected. This is one of many such tools developers would consider using, if not creating their own proprietary software. Professional 3d artists may also use programs such as crazybump to generate normal maps, specular, AO, and slightly modify Diffuse maps realtime.

To elaborate on this topic:

UV Map: I generated this in Headus, so some strange looking angles appear where it would in real life appear straight. This is because texture stretching would otherwise occur, making the material distorted and unable to achieve any desirable results.



Diffuse map: This is otherwise known as a colormap. Contains all your color information.



Specular maps: Contains information to display how shiny your object should be. Should be grayscale, with white being 100 percent shine, and black acting as a matte like material, absorbing light rays instead of reflecting them.



Bump map: This is a technology used to simulate light being reflected at different angles according to your image information. We refer to these as normal maps.




Edit again: I know that photoshop in its newer versions allows you to paint directly onto a 3d model, as long as its unwrapped it should be okay. I have yet to do this myself, preferring to paint in the way I show above. Also note that I am not the greatest texture artist, im still learning. I guess its that kind of programming that would make livery editors possible.

 

[kdryan]

I do the same, I was just keeping it simple...

 

[DylanWhite]

I wouldn't want to explain the entire idea either. lol

 

[TBR 427]

Good idea posting this.
Thanks for explaining all that. I didn't realize just how much work it takes to convert a standard to a premium.
Do you know the difference in number of polygons is in premium vs. standard. GT5 vs. GT4 etc. etc.

Hopefully this doesn't get closed due to a bunch of haters.

The thing is you can't just upgrade a standard car to a premium car. There's aspects of the models tat had to be optimized, and are therefore visibly messy and not smooth, simply due to them being made in 2004 and earlier. For more modern software applications, you need to have a nice, even spread of mesh detail, which better applies itself to subdivision modeling (when you make the basic shape by defining key points placed PERFECTLY then get the computer to smooth out the curves for you.

At best, the standard cars could be used as a bit of a reference, but not much.

Nice post but a few things to remember:

1 When it comes to any modern car, the original manfucturers CAD model probably exists and is easily accessible to be imported for everything from body panels to parts to trim.

nope

If you (ever) get the chance to deal with a CAD model from a company like Volvo or Ferrari or Audi (or whatever) you'll find the following things:

1/ Their file format is usually some semi-proprietary BS that doesn't cleanly import into Maya (what PD use) or Max (what other companies such as RockStar) use.

2/ IF you do get their stuff in, you'll realize it's way way too detailed for your workstation PC, because

3/ They don't model in polygons in any manufacturing program, but Maya has to convert them, meaning

4/ The Volvo model they game you has more polygons than the entire GT5 game, and since they're not natively polygons...

5/ You can't do anything with them apart from look at them, and lament your 1 frame per second performance.


Basically you are given a 100% accurate model that you can't modify, sucks all the performance out of your PC (meaning you can't build around it easily) and takes days to render.

The best thing you can do with them is render out reference images (top/side/front/etc) perfectly, without any perspective). And, once you've finished your work, you can import your stuff into their stuff and compare them (oh this vent I made is the wrong shape compared to the 100% accurate thing, etc).


EDIT:

This works in the opposite direction as well.

For things like the Red Bull X1 aero figures, Red Bull would have had to model it themselves to run the simulations (you see this for a split second in one of the X1 vids). Usually the CFD programs need some sort of .brep (Boundary REPresentation) file format that Maya can't spit out. So they'd be given the 3d model from PD, remake it in their software, perform the tests, and email PD back the downforce numbers, etc.

 

[Supercheyenne]

I'm not a gaming expert but I am a Cad/Cam expert. You can get a "perfect" model from a real life car in less than 40 man hours.

They have technology to scan items in 3d now. Then you just need to touch up some things and clean up the model to get to your desired polygon count. It's really not as complicated as people think. Now I'm not saying a monkey can do it, but you don't have to be a rocket scientist either.

 

[DylanWhite]

I'm not a gaming expert but I am a Cad/Cam expert. You can get a "perfect" model from a real life car in less than 40 man hours.

They have technology to scan items in 3d now. Then you just need to touch up some things and clean up the model to get to your desired polygon count. It's really not as complicated as people think. Now I'm not saying a monkey can do it, but you don't have to be a rocket scientist either.

Yeah!!! I cant wait for this technology to become cheaper. I only heard a little about it, but I was under the impression that the device could only scan small scale items.

 

[R.S]

I'm not a gaming expert but I am a Cad/Cam expert. You can get a "perfect" model from a real life car in less than 40 man hours.

They have technology to scan items in 3d now. Then you just need to touch up some things and clean up the model to get to your desired polygon count. It's really not as complicated as people think. Now I'm not saying a monkey can do it, but you don't have to be a rocket scientist either.

Unfortunately I dont think a 3d scan would be suited to creating models for games at all, afaik the resulting mesh would generally be horrible and certanly not reasonable to "touch up and reduce to the desired poly count"
By design the level of resolution in the scan to get proper shapes on everything on a car would be huge. (unless this machine know how to follow paths and shapes properly, rather than firing lasers millions of times and ending with a point cloud)
To get proper shading and reflection on a polygonal car, you need perfect mesh structure (which has to be optimized) and/or perfect normal map generated from a highly detailed perfect and clean mesh. Neither are an easy to produce, any imperfection in a car body is incredibly visible.
You also need several different models with different levels of detail (LOD)

There are also many different parts on the cars and especially the interior would be incredibly difficult and time consuming to get well textured and normal mapped without distortion.
It takes lots of skill and experience, and is generally not a one person job.

Here are some possible steps to what I know as the basic method, depending on circumstances some steps could not be needed for various parts.
-Referencing
-High detail modelling
-accuracy check
-lesser detail modelling
-multiple different models for different levels of detail
-optimizing
-optimizing (how much can you bring it down without effecting form or shine, how visible is it to the player, does it need to have lots or less detail)
-unwrapping
-normal map(surface direction) baking
-ambient occlusion(fake indirect lighting look-alike for "darkness in concave areas") map baking
-texturing
-specular map (not too sure gt uses this, maybe for some cars interiors)
-shaders
-optimizing
-bringing to life

Also dont forget everyone, all the polygons on the car are not being rendered every frame.
The cars polygons will probably be seperated into seperate objects. Some of these objects are hidden out of the camera view, behind objects and out of reflection paths. Generally they aren't rendered, provided that its more efficient to test whether it should/ or not be rendered than it is to just straight out render it all.
Then there is also LOD (level of detail), depending on distance to the camera and other circumstances the car(and other objects) detail will be continually switched to less and lesser quality versions, possibly even switching to a cheaper less accurate shader. In the simple example of a less detailed track in the rear-view mirror.