Tutorials

Summary

In this tutorial I will try to describe and explain, as far as possible, the process of modeling a car. Do mind: the process, so an overview of the steps I would undertake, not the details of how to model a rear spoiler, or front bumper... Be prepared for a lot of text and very little images!

Once more I would to emphasize: this is how I see the process of modeling a car, my personal view on it. I do not claim it to be how it should be done, it's just a look in the kitchen for all you people out there modeling cars too. Take from it what you like, laugh at what you think is stupid, but learn from it or at least enjoy it. :)

Where to begin?

A good question, and obviously the only question when you want to start modeling a car, and as always there isn't really a definite answer to where. But I can tell you how I would do it, or what I would suggest you to do.

Throughout the first bit of the tutorial I will assume you want to model a car and do not have to model a car. There is a massive difference between modeling something because you want to (personal) and because you have to (work).

So you want to model a car: good, very good. A question like: can I model a car could arise at first, but it's not really important. You can always try and you have to try if you ever want to become a better modeler. So a car it is, yet what car? When modeling something for yourself you could think this is not really important either, but I think it is. I tend to believe that when you model a car and you have some sort of connection with it, that the end result is better and more easily reached too. One is more motivated when one models something that brings out a smile on your face, or gets you going because it makes such a nice noise, looks so nice etc. The whole love for the car in real life (would you model a car that actually exists of course) is a great drive for anyone to make it as good as one can. Suppose I would (for some reason... I wouldn't know why, but just suppose) start to model an Opel Kadett from 1985. I can tell you now that I won't finish it: how can I be motivated to model such a totally crap looking piece of ****? I couldn't, maybe you can, but even so, when I would model a Ferrari F355 (happens to be the car of my dreams), I would give it EVERYTHING I got, put in the hours it takes to make it as good as I can make it.

Modeling a car isn't a one day thing, unless you're some magician. I don't think many can model a high-poly car in a day. I know I can't, and I have been told to be an extremely fast modeler. The modeling alone can take anywhere between 10 and 60 hours or so, depending on the level of detail and how fast you work. But you see the problem here: you seriously have to be motivated to start working on a project like that... 60 hours is comparable to 1.5 full-time working weeks. That's quite a lot.
I am not telling you this to scare you off, but only to make you face reality or know what you're getting into when you start modeling cars. The flipside of the whole story is of course the immense satisfaction of the whole modeling process, the test renders, the final result. To me at least: everytime I see some of the renders that I consider my best work, I get this feeling of pride, of joy and that only gets stronger when you realize how much time is has cost me to learn 3D Max, PhotoShop and to actually build the whole thing. Maybe we're all mad making cars in 3D, but I for one couldn't care less. I love it.

Reference Images

After choosing what car to model, the thing I always do is start looking for reference images. Not a couple, but every single last image you can find on the highest resolution possible. If you know the car you're modeling exists somewhere in your area: try to get a digital camera (if you have one: great, otherwise borrow one) and make as many pictures of the car as possible (car dealerships, private owners (ask them first, some people are a bit freaky about taking pictures of their car)) and especially of the details such as head lights, tail lights, doorhandles, windscreenwipers, interior (if you're up for the modeling of that too), logo's / decals etc. etc. The details are what makes a great car and it's always difficult to see them on wallpaper images which tend to show the whole car.

The second part of the reference image quest: blueprints / 3-view drawings. If you can find these for the car (or whatever you're modeling) you want to model, then that helps immensely. There are a couple big sites on the web (Suurland, SMCars, Blueprints.Onnovanbraam.com) and together they have around 20000 blueprints in total, so if you're lucky enough they have the blueprint you're looking for. Newer cars (last year) and classic cars (70's and older) tend to be more rare, but most 80's and 90's cars are represented, especially the special ones, like italian exotics, M3's, Skylines, Supra's etc..
If you can't find blueprints: that sucks, I personally can't model very well without them. It can be done absolutely, but it's obviously a couple of magnitudes more difficult than when you model from reference. I personally always check if a blueprint exists for the car I want to model... if it doesn't exists (which hasn't happened yet, but then again I haven't modeled that many cars) then I wouldn't start.

The modeling process

The actual modeling process I usually see in a couple of stages:

1. Blueprint setup
2. Body
3. Rims and Tyres
4. Exterior details
5. Interior
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6 + 7. Texturing + Lighting

This is fairly straightforward, apart from things that are normal to me, but I don't think many people do: I split the modeling and the texturing/lighting part completely. I model the entire car (EVERYTHING) without applying any texture to it, apart from a grey clay material. That's right no texturing at all until the whole car is done. No lighting until the whole car is done.
But... WHY? That's what you're probably thinking. And with a reason, because it's not very normal I think. Then again, I am not normal, and I do have a reason to do it this way. Keeping different aspects separated helps me in focussing better: I hate switching between different aspects of a project. I have that with everything I do, whether it be modeling, or making a website: when you focus on one particular aspect of a project you can go up into better, focus completely on a single process, a single thread of the whole wire. Switching back and forth slows anyone down significantly, plus you have to get you're mind switched to every time from polygons to raytraced materials, blurred reflections, opacity, back to polygons, edges, back to specular materials, blend maps etc. etc. It'll slow anyone down and will drain energy.
Another reason to do it the way I do, is because projects can come to a halt halfway more easily because it seems like you achieved quite a deal when you render a body with full textures and some nice lighting, but if you have no windows, no wheels, no rims, no exterior details, what good does it do? I think one tends to get complascent with what one has achieved then, and it's more easy to quit when you have a feeling you're done. Which is obviously not the case: there is loads of work to be done. GET BACK IN THERE SOLDIER! I know it it's easy to fold though, especially when you do something for yourself, in your spare time. Motivating yourself into working that long and/or hard on something with no payment, other than the satisfaction and pride when it's done, isn't easy.

1. Blueprint Setup

The setting up of the blueprints is a 10 minute job at most. You just get the blueprint you found (if you have of course), crop the views in PhotoShop and put them on planes in 3D Max. See also this tutorial I made a while ago.

2. Body

The body of the car: obviously the most important part of the whole car. Use the blueprints as a guidance to modeling it, but never rely on them completely. It is almost never so that the blueprints are very accurate let alone match up in all the views (top, side, front, rear), so use them as a rough outline but double check what you model using the reference photo's you found. Especially check the position of characteristic features of the body: compare their relative sizes and positions compared to other parts of the body or other parts of the car.

3. Rims and Tyres

Ah yes, the wheels. Wheels make or brake a car. Believe me, I have seen a lot of cars in my life (seen seen, as in observed them) and the rims on a car are very important. Yes they can be too big (anyone putting 19" rims under a BMW E36 M3 for instance is nuts! ;) ), they can be too small, they can be wrong and good in a dozen ways. But knowing this: spend time on them when you model them, try to make them accurate. To me they are almost always one of the most enjoyable part of the whole process, because they're like little gems of their own. Also because they have a great variety of texture in all the separate parts (brake disc, brake calliper, the rubber of the wheel itself, bolts, nuts etc.). Of course to each his own, I can't judge taste, but what I do know is that well modeled cars, have well modeled rims and real modeled wheels (including a modeled profile!). For the modeling of the rims see a technique here and for the modeling of the tyres see a technique here.

4. Exterior details

The details are what makes a modeled car look good. Model as much as you want, and realize that the more the better. Not more than there are on the real thing, but as much as you want from those available: door handles, the grill mesh, locks, badges, decals, antennae, little bolts, small hood clips. It can be tedious, but once more I will state it: the more, the merrier. If you can't be bothered anymore but there are still things to be modeled: think about the immense satisfaction of seeing all those details when you render out the entire car at 6000x4000... I know I have done on numerous occasions and I was very happy with all the details I put in there. On large scales the large surfaces tend not to be as important; they are of course, but only as background, or filler for the details. Your eyes, or the ones from whomever looks at the image will trace the image flowing from detail to detail and zoom out to see the whole picture. Details make you want to touch it, make the illusion of it not being real, but looking as if it were real greater, much much greater. It's all in the details, in the subtleties. Beauty lies within subtlety. Chinese wisdom? Maybe, it's what I believe in anyway.

5. Interior

Modeling the interior is difficult, very difficult. Many organic shapes usually, like the dashboard, the seats and others. How detailed you want your interior to be depends on how tinted your windows are (and yes, that's a non-subtle hint) or how little motivation you have left when you are at this stage. Modeling it gives another big leap in realism, but I do have to admit that I never went full-out on it so far, I haven't modeled any interior as well as I could or as well as I should have. You can get very far with modeling the inside of the doors, the seats, the dash and the steering wheel at a medium level of likeness to it's original. Maybe also because I model the cars for their exterior mostly, and make renders of the exterior that I haven't put as much effort in as I have on modeling car bodies. Only the SZ I made has almost everything in the interior, steering wheel, handbrake, gear leaver, seats, rear seats, floor, all gauges in the dashboard (with needles and background textures, yes, thank you very much ;).
So depending on whether you are going to make renders of the interior, or are making a convertible/cabrio, then you have to model it. And I can understand it is great fun, but usually you already have done so much on the rest of the car that you either want to continue to the texturing / rendering part, rather than modeling every single detail of the interior (and believe me, there are more than you can think of, in any car).

6. + 7. Texturing + Lighting

I don't have much to say about these two aspects of the process. Some notes though: decide beforehand which renderer you want to use, switching back and forth between scanline / Brazil / Mental Ray / VRay is horrible half-way: you have to re-do most if not all of your textures. Maybe as an exercise (if you're up for it) you could texture and render the whole car in one renderer and then try to get the same or better result in another, but I wouldn't do that for 'fun', so to say. Obviously you learn a lot doing something like that, you will learn the finer details of the differences in materials and lighting settings... not unimportant at all, but I think I know in which state of mind I am at this stage of the process: I want to get it done and as good as possible, not mess about switching renderers and doing tedious material overhauls.
Again these two steps are vital to a good end result (even though I can enjoy a clay render of a well modeled car as much as any). Don't trust the modern day renderers to do all the work for you. (fake) GI isn't everything, try to get a nice lighting setup going, with or without a studio environment with cards, or even better a real environment such as a parking garage...

Oh, how I dream on of my next project... :)

All in all: that's pretty much all I have to say on this topic. Try to work methodically, make lists of what you want to do (list of objects for instance), to get an overview of yourself of what needs to be done. You usually know for yourself how much work something is, but it's always nice to be able to tick off that object which you were afraid of to model...

Happy modeling!