In the 3D design field, realism is paramount. Whether 3D designers are creating a video game, a television commercial, or a product or automotive photo shoot , the realism of their models and environments is what sets their work apart.
Realistic visuals, though, are only half of the equation. In order to create a truly convincing 3D render, 3D designers need to light their models and scenes accurately.
Image-based lighting is a powerful and flexible technique that allows 3D designers to automatically light their renders using lighting data captured from the real world . Image-based lighting simplifies the process of creating realistic 3D renders and gives 3D designers unparalleled control over the lighting and the look and feel of their work.
At CGI.Backgrounds, we've produced the HDRI maps and backplates required for image-based lighting for over 20 years. Here's a deep dive into the technique, and what 3D designers need to know about IBL.
How Does Image-Based Lighting Work?
When using a DCC (Digital Content Creation) software to create a render, 3D designers generally place one or more models into a virtual environment, add a visual background, create or add objects, and more. The end result is the basic framework for the scene.
To light the scene, designers have a few options. In most DCCs, they can add their own light sources. Manually adding light sources can be a challenge, though. It relies on the designer's intuition to add lighting that perfectly mimics the desired environment of the scene.
Image-based lighting simplifies and improves this process by using HDRi Maps with embedded lighting data to essentially “import” light captured from a real-world location, placing it into the designer's scene.
The Advantages of IBL
Image-based lighting has several advantages. For one thing, it's much faster than creating custom lighting for a scene. Even in a simple DCC, like Adobe Substance Stager , importing an accurate HDRi Map can provide stunning renders with almost no need to tweak the lighting.
Image-based lighting is also more flexible. 3D designers can change the look and feel of their scene by importing different HDRi Maps with different lighting conditions.
For example, a game designer performing a character look study can create their character's 3D model, place them into a simple environment, and then import lighting data from HDRi Maps captured during different times of day , different weather conditions, different sources of directional or colorful light, etc., in order to see how their character will look in a variety of potential game environments.
Likewise, a 3D designer creating an automotive render could import different HDRi Maps in order to show their vehicle in different types of scenes. Because humans respond very emotionally to lighting, this can help create the desired look and feel for their campaign.
The Technical Side of IBL
From a technical standpoint, image-based lighting involves using an HDRi Map captured from a real-world location or, in some cases, created in a studio setting. The term HDRI stands for High Dynamic Range Image . Each pixel in an HDRi Map captures far more data than is visible when the map is displayed on a standard computer monitor.
CGI.Backgrounds RAY.HDR technology, for example, captures tremendous detail in both the highlights and shadows, which far exceeds the detail shown in a tone-mapped, display version. This extra lighting data is what allows an HDRi Map to be used to accurately light a scene via IBL.
In some cases, 3D designers opt to use both the visuals and the IBL data from an HDRi Map. This is optional, though. In many cases, 3D designers either use a fully CG background for the render, use a skybox in a video game context, or use a backplate or other photographic image for the background.
This live stream shows some of the world's most talented 3D designers explaining how they use our HDRi Maps for IBL.
In this case, the designer would only use the lighting data from the HDRi Map and not the visuals. This architectural render from Jay Patel is a perfect example. Patel created the scene in a fully CG environment but used an HDRi Map to achieve the powerful, dramatic lighting in his final render.
Use Cases and Industries for Image-Based Lighting
Image-based lighting is used in a wide variety of industries. At CGI.Backgrounds, we work with all of them, so we can shine some light (pun intended!) on the way this technology is used in the real world.
Automotive Rendering
Car companies were some of the first and most enthusiastic users of image-based lighting technology. Many car brands produce multiple vehicles in multiple trim levels and have long used virtual production techniques to show their vehicles in real-world settings.
Architectural Visualization
When architects create 3D models of a proposed structure, the lighting data can be a big part of selling the design to stakeholders. Light creates the emotional feel of the scene, and achieving the right emotional effect is essential for getting buy-in from a client.
For that reason, 3D designers creating architectural visualizations often experiment with a wide variety of different HDRi Maps, dialing in the perfect light for the render.
Product Photography
3D designers often create fully virtual product shoots using 3D models and scenes. Whether they're visualizing a small product like a wristwatch or even a full fashion line with clothing photographed on actual models, IBL can be a powerful technique for lighting their scenes correctly.
Virtual Production for Films, TV Shows, and Commercials
Virtual production is a fast-growing technique for producing media, such as movies, TV shows, and commercials more quickly and with a lower climate impact.
The technique was popularized by television shows like The Mandalorian. In a studio, a large LED wall is built, and actors and props are filmed in front of the wall. On the LED wall, production designers add visuals that are appropriate to the scene.
This technique allows an entire production to be created in a studio setting without the need to go on location. This saves time, money, and CO2 emissions.
Can 3D Designers Customize IBL Data?
If 3D designers choose to use the image-based lighting technique, are they stuck with the exact lighting present in the HDRi Map they choose?
No, even if they use a real-world HDRi Map, 3D designers have a great deal of control over their lighting environment.
3D designers can use a tool like HDR Light Studio to edit a real-world HDRi Map, adding light sources, reflectors, and other lighting elements. This allows them to start with lighting from the real-world scene but tweak it to make it perfect for the render.
That's one of the reasons that we built such a large collection here at CGI.Backgrounds. We have HDRi Maps from over 7000 real-world locations , which means that in many cases, 3D designers can find the perfect HDRi Map in our collection without the need for extensive editing.
How to Get Started with Image-Based Lighting
The first step to getting started with image-based lighting is checking to see how the process works for your DCC of choice. Almost all popular DCCs support image-based lighting, including Blender, Maya, Substance Stager, 3ds Max, Unreal Engine, and many more.
After that, you'll want to look for a good source of high-quality, professionally shot HDRi Maps with embedded lighting data. The quality of your output is only as good as the quality of the HDRi Map you use, so choosing high-quality Maps is important.
That's another reason that we created our collection of over 7,000 HDRi Maps from locations around the world at CGI.Backgrounds. Our professional photographers capture full IBL data for these locations, allowing you to duplicate the lighting from nearly any type of place in your final scene.
Since we know that many 3D designers try multiple HDRi Maps for each render, we've created a set of inexpensive subscription plans for our collection , as well as a free tier for students and hobbyists just getting started in the 3D design world.
