Rendering of the Car: An Approach to a Creation of the Studio

Rendering of the Car: An Approach to a Creation of the Studio by Alex Novitskiy, Ukraine

This lesson requires the following software: 3ds Max, VRay, Photoshop

At numerous requests of the users of this resource, I decided to write a lesson on studio visualization of the cars, and precisely - on approaches to the creation of the studio in dependence of goal and required style. This lesson is more theoretical - this is its main advantage. I will try to describe the several approaches to a visualization of our car, according to a chosen style and task.

There are a lot of excellent lessons on car modeling, shading and rendering at the internet.   As to the creation of studio in itself, an author shows the concrete example and explains how he did make it. Afterwards, we waste many hours trying to copy it; and we swear, because we haven't got anything good. It happens because we need to adjust the studio individually in each individual case. But very often we see a template, and then we are trying to copy it without a clear understanding. This is a common mistake - not only in 3D graphics. First, you need to understand: there is not a ready scheme for a masterpiece creation: the Make-a-Perfect-Thing button is not invented yet. But there is an algorithm that may help you to realize your ideas. So, that is that? At the beginning, we need to understand some necessary moments - without them any visualization will be only half done or will not impress.

The Form of Submission

You need to establish a clear goal of your car. Here's my advice to turn an attention upon the shape of the car, and understand - what do you want to emphasize, which parts to distinguish, etc. So we determine the form of our submission beforehand. For example, we want to show the aggressiveness of our car by making the sharp glares, «predatory» foreshortening, or conversely - we would like to see a calm and modest car. It will be very useful later - when we will adjust the lightening and during the final submission.

The Style of Submission

Here we need to realize: in which style we want to show our ideas? Will it be a photorealistic or totally non-realistic rendering at the edge of Pin-Up? Actually, there are a lot of subtleties and nuances in the choosing of style and all of them are individually. So don’t afraid to fantasize.

The style also strongly affects on the creation of studio and working with lightening. The initial understanding of your final goal would make the work simpler and make the lightening adjustment process less obstructive. Many people leave these moments, making the additional troubles to themselves.

So, now you clearly defined your task and ready to put an idea into practice.
We will begin by giving a set of test materials to the car. My advice: apply the Multi\Sub-object to a whole car, and use the simplest settings for the tests. Below you can find the most fundamental examples based on the VRayMtl.

Later you could make multi-layered shading on the basis of Shellac, vrayBlendMtl, VrayCarpaintMtl. We will talk about difficult paint materials nearer to the end of the lesson.

All the rest we make by the same principle using VrayMtl - it is exactly what we need for the tests. Then we set the materials, we are ready for the creation of a studio.

The Types of a Studio

1. The studio on the basis of VrayLight Dome (a simulation of lightening).

This is the simplest technique. Here we just simulate the lightening through the gradient ramp texture, which was loaded into the texture slot of the light source of  VrayLight Dome type. The best choice is to find a good hdri and apply a high amount of blur - thus, you will achieve the similar result. It is very important to find the proper map with the precise line of horizon: after the blur, it will be transformed into a nice gradient that simulates the tones of the sky and don't have the completely black tint of the floor. Under the car we create the plane and impose the Matte/Shadow (if you wish, you may adjust a nice floor of the multi - level shader).

It is a really simple method that provides a very smooth transition in lightening, but it requires a creation of the masks and the improvement of a contrast of particular elements, because in this case we use the centralized lightening.

We have got an exaggerated lightening - there is ostensibly daylight lightening, but the whole result is similar to a studio photo: all shades are well merged, and there are no sharp glares or clear reflections. This provides an excellent picture style and creates the simulation of realistic lightning. Frequently it is better not to search the HDRI, but adjust the Gradient Ramp with appropriate settings at once. Also the Gradient Ramp lets to control the blur of a horizon line, its height and lets to saturate our fillings with a missing shade.

With the method described above, you can obtain this result:

2. The Cylindrical Studio. Rendering in the Pin-Up Style.

I have to say that this is the most difficult studio. This is a studio of closed type - so the each relatively powerful light source created inside the studio will affect on a whole studio by reflected light. But, despite of its difficult adjustment, it is the best type of the studio that suitable for creation of «nonrealistic» rendering in the Pin-Up style. Here we can make a very smooth lightening, that goes around the car’s body and gives the sharpness or smoothness, if necessary. The cylindrical studio also is convenient for creation of the «effect of lollipop».

So, the studio looks like this:

We create the cylinder, and we make the chamfers at top and bottom. It is better to make this cylinder completely closed. We need more polygons for the bottom chamfer and the bend must be smoother. Then, we choose the Turbosmooth for our cylinder, using 2 iterations.

To avoid a problem with a camera, we work in the Wireframe mode, and we turn off the Visibility for the cameras of our studio. Right click the mouse and choose the Object properties:

Now the reflections will be visible only at our car. There is no reason to turn off the visibility of studio to see how the light reflects from the studio. Here we could make a trick - cut the studio into two parts and remain one of them visible. You may cut just as you like, but it will be better to do it in order of visual comfort. Also there is a reason to make the transparent part barely visible, setting its visibility at 0,4 - to completely embrace every working light source. Afterwards, we will turn off our studio in any case and will work only with the model. It is no problem, if your camera will be outside the studio - as in my case. Later you must make invisible the facing (to the camera) part of the studio. 

We apply the most usual material for the object, changing only a color. Increasing the reflectivity of the studio will strongly affect the picture. All depends on the initial idea, therefore there are a lot of variants. I have only advice: there is a good opportunity to experiment, so don’t afraid.

Now, we will try to create the light source in our studio. If you will turn the multiplier, you immediately will see how strong the reflecting light starts to work. We don’t touch the Indirect Illumination at the present.

When we loaded the model, we are feeling a temptation to throw the light immediately, but it is initially wrong. I always advice to select the beginning point - the light source that will make the first line of our car. In this studio, I prefer to use only the reflected light, except the filling (по diffuse) and the glares (specular). Therefore, the VrayLight of the Plane type is the best choice in this case.

First, let's try to set the one light source to accent the shape and illumine the car. Here, I repeat, many depend on chosen style and automobile model.

In this case, you can see the overexposure. Therefore, we need to adjust the brightness of a light source right now. For better understanding how the light spreads within the studio, just don’t turn off the visibility of rear half of studio (as for me, it is more convenient to work only with the model, so I hide the rest).

We adjusted the brightness and obtained this result:

Unattractively. But it is not terrible - we already felt the effect of that light source and realized its role in our studio. We need to add some other light sources. Their disposition is shown below:

For filling and glare, here are the light sources of Spotlight and Omni types. There is no reason to turn off the influence of light sources on the Disffuse, Specular or Reflection without necessity.

The picture became brighter, but it is not rich or expressive. But, it is not necessary in this case. The main goal here is to realize: which moments are left without care; what is absorbed by a shadow; where is an overexposure?

After the visual and analytical work we can clearly realize - where we need an additional filling; where we need to add color - maybe, blue or yellow; and where we need to make a glare.

When we will see that the shape plays, then we may try to add some cosmetics and play with light boxes or plains with filling of Gradient Ramp type. I will tell about that later.

When we feel that the light is suitable, we turn the Unhide to whole model and continue with testing of all details. To make the test work faster, try to apply a test material initially to all parts. Final materials you can apply later.

And, after a short fuss with additional light, color, adjusting of emitting GI polygons and short work in post we receive the ready picture.

3. The Combined Studio

Now, let’s pass in the last type of the studio that are described in this lesson - to a combined studio. This studio is the best if you want to create a photorealistic rendering and is the easiest in adjustment and the most flexible for the light sources tuning.

I used this type of studio to create the light for my Mercedes and emphasize its lines by the light that reflects from the planes located under the car. It is very similar to the real photographic studio.

Here is the same sense as in previous studio, except that the light source control in this case is located upper. Our space is not closed, and if necessary, we may even add the hdri or Gradient Ramp to the light source of the dome light type.

For better light reflection, it is desirable to make the reflective floor.

Using these plains, we can make any backlight by adjusting the gaps between the planes and throwing the light from above or from down. In case of necessity, you can shade from above by completely black plain. It is more convenient than working with gradients and self-lightening materials. And it is more clear - it is important.

In general, if it's possible, my advice to turn on the Vray RT and make the ActiveShade from the window of perspective and rotate the studio often - it is very useful for realizing how the light works. The real time rendering provides the visibility and helps in understanding how the light works in the scene.

Every light source should be adjusted thoroughly, and you need to watch how it works in reflections. This process is highly individual for each car and depends on many factors, including the factors described above.

The lightning adjustment process is similar to the one described in previous studio, except that now we can use the hdri for an additional gleam of light and for small glares. It is not necessary, but if you have a previously created the hdri studio maps, they could be used for the acceleration of rendering and for the simplification of creation of the lightning.

How to make fine smooth lines at one side:

Also there is a method of self-lightening materials:

If necessary, also you may add the Opacity and make needed glare as a plain. But my advice always to work with lightening, if it's possible.

The Materials

Usually, the materials for automotive painting - is the first task to be solved when we finished with setting of lightening. There are many ways to create a fine material, but in most cases the simplest material is the best material. Here I want to say: the material that we used during tests could get a good result in the properly adjusted studio.  It is mistaken to think that all depends only on material - but it is also mistakenly totally to forget about the material.

Thanks to Vray, we have got a nice Vraypaint material that makes our lives more easily. But usually for obtaining the certain result is necessary to create our own material that will work as we desire.

I give an example on the black paint, because it is the most universal paint. There are many refinements in the color paints that depend on color combinations and different settings. I show only a mechanism that often helps me, but the rest depends on concrete task.

So, there are three approaches to the creation of a material. First - the usual VrayMtl that we used for the test. If we add a pair of map on reflection and color, we could obtain an excellent paint material. For example, I used exactly this simplest material for my Opel Kapitan.

But keep in mind, that due to its simplicity it will be a not right material and it is better to take as a basis the Shellac or Blend, if it's possible.

The real automotive paint consists of many layers, therefore you need to calculate all these layers if you want to create a right effect.

The Shellac Material 


The Blend

By this approach, you can create a quite realistic paint. Further all depends only on knowledge and fantasy.

For other materials the principle is the same. But, because the color of the paint is always difficult - I give more attention to it.

I will not to describe other materials; I have many told about the material of paint - it is more matter of searching and taste than real problems with adjusting.

In general, my advice to test any material with different hdri and realize how it works with different lightening and color

Some Advices on Post-processing

It is a subject for many talking, because everyone has its own approach. By the way, it is possible to finish the rendering of studio in itself later. For example, the shadow under car.

But here, it seems to me that is more important to understand the laws of perspective, and to feel the light and color - in this case all the corrections will be good in the picture and will not be looked as a blind «blurring» of good rendering. The art features during the post-processing is the most important - they are only who hint you how and where you need to correct, to illuminate, to shade, etc. So don’t afraid to try a different method to make a processing most easy and convenient - up to "in-parts" visualization described above.

When I tell «in-parts», I don’t mean a separately adjusting of Diffuse, Reflections, Occlusion, etc. It is easier to adjust scene in detail in 3ds Max, and then to visualize the car in itself (completely), hiding the rest of the camera. It will make a post-processing a little easier and will let the ability of fast correction of any element. I did make my Mercedes in this way.

The most important here - to get a mask for the car, so then you can click on a needed element and make it brighter/darker. It can be done through the usual VrayLightMtl.

The process goes further in each case individually. But the logic here is a simple: adjust colors, shades, and play with a common gamut.

There is a sense of using a Curves in Photoshop during the further work with a picture (Create new fill or adjustment layer -> Curves). Give a shade that corresponds to a mood - and you will increase the general impression of the picture.

Also you can use the Curves to make the effect more close to a cross-process to simulate an effect of old photos, or more exactly - an effect of development of the photo, a displacement of colors. I used this effect for the creation of color for my Opel Kapitan. The renders in itself were stored in black-and-white variant.

The adjustment of the displacement for the Opel is shown below:

Also there are some important moments in the visualization and processing of the car:

1. Try to use a golden section. All that is within it will be playing good when a spectator will precept the picture. Therefore, it is desired to set the car in such way that its most interesting parts will be in a golden section and the light will work well on these parts.
   
2. Try to keep the common style in all: beginning from a texture and finishing with a common gamut, a headlight shade color, a position of light in a scene. The final result strongly depends on your initial vision of a picture.
   
3. Avoid the «flatness» effect and «non-tasty» foreshortening. The dynamics (or statics) very often is set into a foreshortening and creates the general perception of the car. It is easy to understand what I’m talking about: there are a lot cooler cars photos on the internet that are looking as «weak» or vice versa - a lot of photos of absolutely non-interesting cars  that are looking lively and charismatic at a proper submission.
   
4. Don’t afraid and don't be lazy to experiment.  Often, the most interesting methods form during an experiment.
   
5. Even when working only with one foreshortening, rotate the model often and look how the adjusted light covers the different car parts.

So, we passed through the theoretical part and slightly touched a practice. Alas, to say more, I need to expand every point in several times that will only complicate the perception of information. I tried to describe very basic elements that often obstruct to an expert to present their work handsomely and present something beautiful to the world.

I hope, this lesson will help to many creative individuals and allow them to approach the solving the tasks of visualization and adjustment of the studio more boldly.

Creative success to anyone!