Apart from the default render engines that come with 3ds Max, several extra renderers are available. Of all the 3rd party renders on the market, however, V-Ray has proven time and time again to be the most popular. In this tutorial, you will be introduced to lighting and rendering an outdoor scene with V-Ray in 3DS Max.
This tutorial will walk you through the process of taking a finished model from it's default rendered appearance, to a correctly set-up, and realistically lit final result. You will learn the basic V-Ray settings, that should always be set up for any scene, how to use a Gamma correct workflow, how to set lighting and global illumination settings, and how to optimize those settings. Note: This tutorial is meant to introduce a user, familiar with basic rendering in 3DS Max, to using V-Ray in a correct workflow. It will not teach you how to model the scene used in the images, as that is not our focus.
The software used will be 3DS Max 2009 together with V-Ray 1.5, but using another version of 3DS Max should not be a problem, although minor differences in settings might be necessary. You can download the project file from the following link if you would like to look at (or play with) the settings, but you will need to have the above mentioned software to open it.
Final Effect Preview
First of all, when rendering scenes with realistic global illumination, it is very important to work with gamma-correct settings. In short, this means we adjust 3DS Max's settings to display brightness levels as you perceive them in real life.
Go to "Customize" > "Preferences", and select the "Gamma and LUT" tab. Any settings that you need to change, or pay attention to, will always be marked with a red border. It is very important to make sure that your screen or videocard display settings are set so that the gamma preview image blends together as one single grey value when viewed from a distance.
Next, go to "Rendering" > "Render Setup" (F10 on your keyboard). The "Common" tab should be active. Scroll all the way down, and open the "Assign Renderer" rollout. Hit the button next to the name of the "Production:" renderer to get a list of installed render engines. Choose "V-Ray 1.50" from the list and hit OK. The tabs in the "Render Settings" dialog should change to include, among others, a "V-Ray" tab.
For now, close the "Render Settings". Hit 'F9' to start a first test render with "V-Ray". You will notice "V-Ray" renders with small squares running across your render, these are called 'buckets'. My scene is Tod Williams' 1978 Tarlo House in Suffolk County, NY. I chose this subject because it was easy to model, yet still looks interesting enough as a subject for this tutorial. You might notice that my background color is grey instead of black. You can do the same via "Rendering" > "Environment", or hitting '8' on your keyboard, but it is not really important since we will change this in a few steps anyway.
The first thing you should always do when setting up rendering, is change your "Antialiasing" filter. Hit 'F10' again, to bring up the "Render Settings" window, and go to the "V-Ray" tab. The rollout we want is the "Image sampler" (Antialiasing) rollout. Change the drop down for the filter from "Area" to "Catmull-Rom". "Area" is the default filter, which looks blurry and un-sharp compared to other more advanced ones. You don't have to use "Catmull-Rom", "Lanczos", and "Mitchell-Netravali" are also okay, but I prefer the crisp look "Catmull-Rom" gives me.
Close the "Render Settings", and render again by hitting 'F9'. The difference in changing the "Antialiasing" filter should be visible already.
Next, you will set up a camera. In 3ds Max, you can create a camera from a view by pressing "Ctrl + C" in a perspective viewport. So, try to find a camera angle that is aesthetically pleasing, and hit "Ctrl + C". This creates a default 3ds Max Camera, as you should be able to see from other views. You can switch a viewport back to perspective mode by hitting 'P' while in it. Hitting 'C' will return the viewport back to camera mode, or present you with a list of camera's if there are multiple cameras in the scene.
"V-Ray" has a special, proprietary camera, called a "V-Ray Physical Camera". This camera behaves like a real-life camera with F-number, shutter speed, and ISO values. The main reason you should use it is because you have more realistic control over your renders, and you won't have to tweak your "V-Ray" light settings, since their default values are meant to work with the "Physical Camera".
In the "Primitives" tab, go to the "Cameras" section, and change the drop down to "VRay". Create a "Physical Camera" at about the same location as the standard camera. Now, use the "Align" tool (highlighted red in the top left corner) to align your "Physical Camera" to the standard camera. Do the same thing with the "Physical Camera's" target.
Delete the standard camera (you won't need it anymore). Change your view to look through your new "V-Ray Physical Camera". Now hit 'F9' to test render again. You should immediately see that our render has gone a lot darker. This is because the brightness the "Vray Physical Camera" expects from lights is much higher than the default brightness of standard 3ds Max lights. You will also notice the "Antialiasing" quality has gone down. This is actually normal, since "V-Ray" adapts it's "Antialiasing" quality based on brightness and contrast (remember the "Adaptive subdivision" sampler from the "Antialiasing" rollout).
To fix your brightness problem, you need to set up some lights. We are going to use a "Daylight" system to create a sunlight in our scene. The advantage of this system is that it has an easy interface for correct sun positions and movement. Go to the "Systems" button, of the "Create" tab, and create a "Daylight" object, at the center of your scene. The size of this object does not matter. Once created, you can rotate it to change the compass direction.
The "Daylight" system automatically created a sunlight attached to it. Select this light, called the "Assembly Head", and change the highlighted drop downs to use a "VraySun", instead of a standard light, and disable the "Skylight". The "Skylight" is not an object in "V-Ray", but a render setting (we will talk more on this later). Remember that adjusting the "VraySun's" parameters happens through here. Since we are using a "Physical Camera", however, this is not necessary, as the default values will work fine.
With the "Daylight Assembly Head" selected, go to the "Motion" tab. Here you will change the sun's "azimuth" and "altitude" to your liking, by using the "Time" settings. What is interesting here, is that you can also select a location somewhere on earth and the daylight system will automatically adjust the sun to behave like on that location. Click "Get Location", and click on a location on the world map to select it. I used the approximate location of "Suffolk County", NY.
Once you have a basic set up, hit 'F9' to test render again. With a default "VraySun", and a default "Physical Camera", your result should look like below. At this point, feel free to make more test renders, to find a sun position that is to your liking.
The previous renders were a little overblown, so select your "Physical Camera" to change some of its settings. There are quite a few, but "F-number", "Shutter Speed", and "Film Speed" (ISO), are the most important ones for the moment. In real life, there is a rule in photography called the "Sunny 16 rule". This rule states "On a sunny day, set aperture to f/16, and shutter speed to the ISO film speed." So in our case, we will go for an "F-number" of '16', an "ISO" of '100', and a "Shutter Speed" of '125' (a small deviation is fine). These numbers are a starting point for further tweaking. Keep the following in mind regarding these three settings: the lower the "F-number", the lower the "Shutter Speed", and the higher the "ISO", the brighter your image will be.
Render again. You will notice the scene got darker, and now seems a bit under lit. You will also probably notice that your shadows are completely black. This is because we have not activated a "Skylight" with "Indirect Illumination" yet. Once we do this, we will get much more realistic lighting results.
Open your "Render Settings" again. In the "V-Ray" tab, open the "Environment" rollout. Enable the "GI Environment" (skylight) override by checking the tickbox. Change the color from a slight blue, to white. This is how you activate a skylight in "V-Ray", as mentioned earlier.
Next, go to the "Indirect Illumination" tab. Activate it by checking the tickbox in the upper left corner. This tab has a wealth of options and possibilities, but for this tutorial, there is no need to complicate things, as default settings will mostly work fine. It is important to lower the quality of the "Irradiance" map (a method for calculating "Indirect Illumination") for test rendering purposes. This will reduce render times by a magnitude of up to '4', with more than adequate visual results for previewing. Just change the dropdown to "Low" instead of "High". Checking the "Show Calc. Phase" tickbox tells "V-Ray" to show you what it does while pre-calculating the "Irradiance" map, making rendering less boring to look at.
Time to render again. After a render, with an interesting pre-pass or two, you should see a result that's starting to look more like what we want. Shadows are not pure black anymore, and the lighting generally became a lot more interesting to look at. The only problem on the image below, is how the light seems to reflect a little bit too strongly in some corners.
The strong light reflection is because, until now, the material in the scene was pure white. This is almost never a good idea, just as using pure black, red, green, or blue on an object is not done. Change the material color to a warm white value. To make the scene a little bit more interesting, assign a "VrayMaterial" with reflections enabled to the windows. To change a standard material, click the material name in the top right, and select a "VrayMtl" from the list that is presented. The settings for this reflective material are highlighted. You can skip this step if you like, as it is not the focus of this tutorial.
Render again. The results of the newly chosen materials should be obvious, as the strong light bounce is almost completely gone.
The previous image is still a little bit under lit. Playing with the shutter speed will show that a value of '90' looks best (remember that lowering shutter speed increases the image brightness). Adjust the white balance to your liking, choosing a warm, orange-ish white as balance will cool the image colors down, while choosing a cold, blueish white as balance can warm the image colors up. The default blueish white makes for a result that is much too warm, so change this color to a warmer white. Optionally, you can increase the vignetting value a bit more, to make the darkened vignet edges more obvious.
Time for another test render. The changes should once again be obvious, and this result should be adequate enough to end our test rendering phase. We can now start increasing the settings for our final image. This render might still be a little bit under lit, and can do with some more balancing of the brightness levels, but instead of spending a lot of time on this in 3ds Max, we will opt to change these settings in Photoshop afterwards. Remember, in 3D, the final result is what matters, so if getting there through Photoshop is easier and faster, then there is no reason not to do so!
Go back to the "Indirect Illumination" settings. For higher quality renders, an "Irradiance" map setting of "Medium" should do the job most of the time. A setting of "High" should only be used when absolutely necessary, as it increases render times almost to a disproportionate level. An interesting way of increasing quality is by enabling "Detail enhancement". This tells "V-Ray" to locally increase the lighting quality where necessary, and can even allow for a "Low" preset to be used, instead of "Medium" or "High" in some occasions. "Detail enhancement" also adds quite a lot to render times, but in certain cases, it is almost a must (the smaller and the more geometric detail your object has, the more necessary this option becomes).
Change your camera angle so it is a bit more to your liking. I chose for a more dramatic wide shot here.
To illustrate the effect of "Gamma correct" settings and workflow, I saved the image without "Gamma correction", and then blended between the two. It would have been a lot more difficult to tweak the settings to look the same without "Gamma correction". Especially the "Indirect Illumination" suffers from not using "Gamma correction".
Once you're happy with your render quality, and resolution, save it, and then open it in Photoshop. In this case, using "Image" > "Auto Color", and then "Edit" > "Fade Auto Color" to 50% should prove enough to fix the levels. Feel free to try anything else you want in Photoshop. "Image" > "Auto Levels" or "Auto Contrast" might also work, but "Fading" them might prove necessary either way.