How a car is made...

  • Thread starter kdryan
  • 48 comments
  • 7,023 views
Going on from what R.S has said, there's some tricks.

The culling purposes, the cars have different model tags depending on what camera you're using.

For example, there would be an 'interior' tag for some meshes, just the entire interior HQ model, the hood, the spoiler, and anything visible from the interior view. Things like outside door panels, wheels (in most cases), etc would not be rendered by the camera tagged 'interior'. So on a camera-by-camera basis they can pick out what to render by assigning bits a different tag or 3.

That interior 'layer' is then drawn on top of the rest of the scene (track, other cars, smoke, etc), helping to avoid front brake lock-up smoke from going into the cabin, and keeping the rain drops outside the windscreen.


There's also the ingenious materials system they've put in place for the thousands of colours. For each car they'll have a
normal map (the cars is mostly smooth, so this is for bumpy bits like Carbon Fiber, door handles, key holes, fuel fillers, etc), everything else I imagine would be basically that one blue tinge.
AO map (for good lighting around detailed areas)
diffuse, now this is the nice bit. It looks like it's be one pixel, one defined colour!
Spec, this is a tricky one, but I think they're giving it another colour (what colour you get in the light, AND another value for how shiny it would be

As well as whatever cube maps and what not they're tossing on.

They're probably all compiled from layers into several (4 or 5?) materials that are applied to the car when the car painting animation plays!
 
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.

I concur with R.S. above. I've been using several different CAD programs on a daily basis for about the last 5-6 years (and I still wouldn't call myself an expert, far from it even, it's a pretty huge and diverse field) and I've seen/messed around with a model of an engine created by a 3D scanning laser at Ford. I'm also no expert on Maya or 3D graphics software but I'm pretty sure there is no way that that 3D laser scanned Ford model could be imported or reformated to work with PDs 3D modelling software. Granted this was a couple years ago and maybe you are talking about some newer thing I haven't seen but keep in mind the functions and purposes behind CAD and 3D graphics modelling are really quite different and there exists very few reasons why their software would/should be compatible.
 
I know hardly anything about what I've read in this thread but enjoyed it all the same. I'm amazed how much can be done. Compared to what I learnt using CAD when I was young this is rocket science!
 
I model with Lightwave 3D from Newtek, never model a car. Here are a few of my models.

rudeboy.jpg


scorpian.jpg


atpt.jpg


x-wing_008.jpg
 
I was under the impression that 3d models in f1 and aerospace are produced using Catia(spelling maybe wrong) this allowed them to produce the model and package everything together. I realise that gaming is different. But I would expect no compatability between the programs as the final function is different.

Any one know the polygon count for the film Cars. This is just for comparison from a cgi film to game
 
I was under the impression that 3d models in f1 and aerospace are produced using Catia(spelling maybe wrong) this allowed them to produce the model and package everything together. I realise that gaming is different. But I would expect no compatability between the programs as the final function is different.

Any one know the polygon count for the film Cars. This is just for comparison from a cgi film to game

SERIOUS BSNS applications (like those being used at Merc, Volvo, Audi, etc) use their own software. Autodesk has a range of products specifically for manufacturing and designing even for different materials. And beyond that, many companies would specifically modify or create their own software.

Catia is just one of many, at other levels of design/production/conceptualizing/engineering/messing-arouding you could be dealing with vanilla CAD, Inventor, SolidWorks, or any of the variations.


There is SOME cross-compatibility between (for example) AuoCAD and Maya. There was a plugin for Maya 09 I used to use (dwg-importer I think? probably still exists) that allows it to deal with SOME cad files, but you couldn't export them back to CAD once they've been Maya'd. And it wasn't able to deal with certain aspects of the CAD files.


For the Pixar movies, They MIGHT be using fully SUB-D modeling now. Apparently dreamworks is still using their own NURBS software, but that's because they only know how to make one face.
4175.jpg

Somewhere around my pigsty of a desktop I've got a picture of Buzz Lightyear's face in their software, it's definately Subdivision. As for the poly count, LightBeer's face alone is probably 20 million, if not much much more. They don't have to render 60 frames each second (more like 5 a day will all the servers up), and more polygons=better, so they crank it up and go for gold.
 
R.S
Unfortunately I dont think a 3d scan would be suited to creating models for games at all....


Pretty sure that's how they do it.

I've seen a picture (on this site) of Turn10 (Forza) scanning life sized cars. AND it also explains why one of the GT5 cars had the markings on it's undercarriage (because PD scans collector scale cars but forgot to clean one up).


I just set the record for brackets in a post! Hope I get a cookie.
 
Thanks I have heard that Pixar use custom servers for their design process. I know that it was going to be a lot more polygons but I wasn't expecting that amount.
 
Thanks I have heard that Pixar use custom servers for their design process. I know that it was going to be a lot more polygons but I wasn't expecting that amount.

Their polygon 'budget' (how many the artists can use) is proportional to their actual budget because it isn't rendered in real time. Ideally you would set the polygon density so that there's dozens of polygons rendered in each pixel so you get super-accurate curves and detail.

Think of how much money they're dealing with, and what kind of rendering hardware that buys.
 
Supercheyenne
Pretty sure that's how they do it.

I've seen a picture (on this site) of Turn10 (Forza) scanning life sized cars. AND it also explains why one of the GT5 cars had the markings on it's undercarriage (because PD scans collector scale cars but forgot to clean one up).

I just set the record for brackets in a post! Hope I get a cookie.

I've seen that turn 10 footage also but it's two different laser scanning processes that are being discussed. The process that manufacturers use (as R.S. described quite well) takes millions upon millions of points from the actual surface of something. I'm sure the resolution is adjustable but I'm also fairly sure that it can be set to sub-millimeter accuracy. The process that turn 10 or pd would be using includes attaching some reflective reference-point type grid (or similar) to a surface and scanning that. It is much less accurate but also much quicker to do it that way. They really don't need millimeter accuracy for their purposes, it is more about getting the proportions right so that it looks good in-game. The point here being the laser scanning for the game is only a small part of the process that doesn't make it much easier or quicker like you made it sound and is different from what would be used in CAD software. Most of the work is done by hand by 3D artists. Also the markings on the undercarriage thing was not because of 3d scanning but from making textures from photos of model cars (i think but I could be wrong).
 
Last edited:
Although I haven't modeled a car in a while, I do model aircraft. I also know lots of other people who model, with a few who do it for a living. I actually have seen people model complete cars in just a few weeks on their own, and they would be pretty damn close to GT5 Premium level cars (100,000+ polygons). I personally haven't modeled a car with more than 50,000 polygons though lol... But I can make some pretty good results with just that amount of polygons. Personally, I wish PD had taken a middle ground, and maybe cut back on the extreme level of detail found in GT5 cars. Not a whole lot though, but just a tad. At least enough to cut down on development time. Also I think they probably should have hired more modeling staff. Though, I do not know how hard it may be to find good modeling talent in Japan...
Anyway since others have posted some of their own models, I guess I should for the sake of adding in to the fun :)


(98,516 triangles with weapons, 34,968 clean)


(15,626 triangles)


^ Yeah, I keep my meshes simple and rather low-poly lol...


(4,904 triangles)


(12,278 triangles)


(20,351 triangles)

If I am VERY motivated, I can make a complete low-poly car in about 2-3 weeks, otherwise they kinda get partially done or never get done... lol
Aircraft I can make in anywhere from a couple days to a few weeks, since most all are my own designs so I don't have to follow tons of reference pics to get them accurate.
 
at the end of the day, thats their job, so just cos its hard doesnt mean that you should justify any shortcomings, they chose that job
 
I don't see how this post is going to link to PD's defense.

It's not about defending PD. It's just trying to help people understand a bit better about why things are the way they are. I have been one of the most vocal in representing the flaws of this game, but not because of the content. My problem has always been the half-assed way they released it. Had they done it right, I truly think everyone would be screaming how awesome it is.
 
I've seen that turn 10 footage also but it's two different laser scanning processes that are being discussed. The process that manufacturers use (as R.S. described quite well) takes millions upon millions of points from the actual surface of something. I'm sure the resolution is adjustable but I'm also fairly sure that it can be set to sub-millimeter accuracy. The process that turn 10 or pd would be using includes attaching some reflective reference-point type grid (or similar) to a surface and scanning that. It is much less accurate but also much quicker to do it that way. They really don't need millimeter accuracy for their purposes, it is more about getting the proportions right so that it looks good in-game. The point here being the laser scanning for the game is only a small part of the process that doesn't make it much easier or quicker like you made it sound and is different from what would be used in CAD software. Most of the work is done by hand by 3D artists. Also the markings on the undercarriage thing was not because of 3d scanning but from making textures from photos of model cars (i think but I could be wrong).
T10 does not use laser scanning, that vid was an example of contact-based scanning:
http://www.ghost3d.com/G3D_MG_Tutorial_digitize_head_1.htm

An exception because they outsource almost all the modelling unlike PD.

PD is also known to laser scan the 'best in show' SEMA cars:
http://jalopnik.com/#!238136/from-bucket-to-binary-morrison-corvette-scanned-into-gran-turismo

They also use CAD data, photos, by hand measures on real parts, model cars, etc...
 
Last edited:
T10 does not use laser scanning, that vid was an example of contact-based scanning:
http://www.ghost3d.com/G3D_MG_Tutorial_digitize_head_1.htm

An exception because they outsource almost all the modelling unlike PD.

PD is also known to laser scan the 'best in show' SEMA cars:
http://jalopnik.com/#!238136/from-bucket-to-binary-morrison-corvette-scanned-into-gran-turismo

They also use CAD data, photos, by hand measures on real parts, model cars, etc...


Sadly that Jalopnik article was lacking in technical info, but I stand corrected it sounds like PD is using much more sophisticated hardware than I had thought. Sounds like you really know what you are talking about though 👍, do you know what kind of CAD data and how they use it? Do they actually get it from manufacturers or make it themselves? I'm pretty curious about that.
 
A few points..

-CAD and 3G game modeling are completely different.
-3d laser scans don't work for game models without huge amounts of remodeling, really only useful for reference
-CAD files from car manufacturers (rarely available) are as someone else mentioned good for reference but not much else.
-prebuilt car models are generally useless, you require models made in a specific way, usually a proprietry way depending on your ingame engine
-the gt3/4 models are low mesh with texture detailing, there is no way you could 'res them up', it's like trying to convert a VHS video to bluray HD with 5.1 surround sound

There is a lot to learn on this subject!
 
Back