Advanced Lighting: Light Balance with 3ds Max
Figure 1: Lighted scene
The Light at the End of the Tunnel
In the December 2015 issue, I discussed the basics of the 3ds Max® lighting system, light setup, and analysis using the 3ds Max Light Meter. This month I’d like to dive into a more advanced topic with light called light balance and how it’s applied to our scenes. At the end of this article you should view your renderings differently and produce a more professional and realistic final product.
For the sake of visualization with 3ds Max, I’d describe light balance as our efforts to negate the negative effects lights and shadows have on our scene based on lighting placement and values, making our scenes appear unrealistic and lower quality.
First, let’s talk about the physics of lighting as it relates to the visualization industry. They don’t matter. Well, they matter very little. Now, for those who came out of the womb pocket protector and calculator first, give me a minute before your head explodes to present my case. The ability to create a good rendering is not particularly based on a formula, but more on our ability to bend values in 3ds Max to present our scene as professionally or artistically as we want. The same applies to lighting. Instead of applying an exact formula, we need to use common sense and apply a litmus-test approach to viewing our scenes to decide whether our scene “just can’t be right” or “looks about right” and present it as professionally as possible.
Let’s start by looking at Figure 2. Can you point out what makes the scene appear unbalanced? If you turn your attention to the sidewalk you’ll see that it’s very bright, while at the same time if you focus underneath the eave on the porch you’ll find the shadows are very dark. While our thoughts may not have been driven to these locations without them being pointed out, viewers apply their own senses to determine the scene “just can’t be right” and decide that it’s a computer-generated image within nanoseconds. As visualization experts, our job is to trick the viewers by bending the values in 3ds Max to balance the scene and make it appear realistic.
What Is Real?
In the case of Figure 2 we need to understand how natural lights and shadows work and how it should be applied. There are three factors to consider. One is that exterior natural light washes out our environment in a uniform manner, creating smoother shadows with a softer contrast. This is caused by natural effects as well as light deflecting off the various surfaces and materials all around us. The second factor is that the human eye is able to compute light and shadows extraordinarily in real life.
An example would be watching an Ipod in a dark room. The Ipod illuminates the room very little, but after our eyes adjust we are able to capture extraordinary detail in almost every corner of the room. The third factor is that digital reproductions by computer, camera, or phone often distort colors of a scene in its attempt to replicate it. In photography this is corrected with attachments and camera settings or corrected in post process. 3ds Max does not do any of these naturally so we need to work with the lights and values inside the software to ensure our scenes look appropriate.
One additional item worth noting that can contribute to a scene appearing unrealistic is the temperature related to the lighting. Essentially the tint of light can vary from cool to warm in a unit of measurement called “Kelvin.” The effect a tint of light has on a scene or object can increase or decrease its realism. For example, if we want to create a candle that appeared realistic we would use an orange tint, not blue. In Figure 3 you can review a guide to understand how the tint of light affects a scene, its mood, and appropriate places they might be used.
Working Inside 3ds Max
The best way to get started practicing light balance is working with a single object. See Figure 4.
In comparison to Figure 2 presented in this article, notice the softer shadows and contrast between light and dark, creating more balance and contributing to more realism. For this scene, balance was achieved using three light sources. First there is the primary light. This light is perhaps the strongest light meant to control the shadows direction and is generally warm. Next is the secondary light meant to reduce the darkness of shadows and is generally more cool. Finally, the background light, or fill light, meant to cover areas that remain in shadow (primarily behind the object). One particular item to note is by utilizing the primary light with a warmer tint and a secondary light with a cooler tint we are essentially creating a chromatic effect that helps to better balance the scene. One additional tip: it is simpler to review the light balance in a scene prior to applying materials. A good material to start from is a light to medium gray standard material, or the default Vray material. Alternately, Vray users can rely on the global switch to override the material settings during render for review.
With the ability to render out the specular, shadows, reflection, refraction, and illumination elements of our scenes as images, we can manipulate them with software such as Photoshop to increase the quality of our final production. This allows us to further manipulate our scene to balance the light and shadows to appear more realistic. To demonstrate this, I used the “Studio Scene Share” example file provided with 3ds Max and rendered out the elements presented in Figure 5.
Using Photoshop, we can overlay the various elements and adjust them to manipulate the various results. See Figure 6 examples.
To accomplish this, navigate to the Render Setup dialog box, select Render Elements, then choose “Add” and select the elements you wish to render out separately as shown in Figure 7. Be sure to add the output path for each element when selecting them.
Light balance can be key to presenting a realistic and professional scene. By focusing our attention on the details in our scene related to lights and shadows themselves, we can work to remove anomalies that cause our viewers to question whether or not our scene is real and if it was intended to be that way.