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What is Image-Based Lighting (IBL)? The Ultimate Guide for 3D Designers

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. 
For example, for an automotive render of a vehicle on a coastal road, the designer would need to add light that accurately reflects the color temperature and direction of the sun, reflections off the water, and much more.
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.
With IBL, designers don't need to guess at how the light in a particular scene will look. They can choose an HDRi Map that has the lighting, look, and feel they're seeking, and then simply import it into their DCC to achieve accurate and beautiful lighting.

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.
Image-based lighting can also be more accurate than lighting designed by hand. Even the best 3D designers often struggle to perfectly duplicate the natural lighting present in a real-world scene. Because image-based lighting duplicates the exact light in a scene, it's an accurate reflection of how a real-world place was lit.

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.
Again, IBL is even useful when creating scenes that are clearly fully CGI. A video game designer, for example, could design an alien world for the visual environment of an environment, but use a real-world HDRi Map to light the skybox accurately–perhaps selecting an image of an appropriately “alien” environment on planet earth, or even using a HDRi Map of a celestial body like the moon.

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.
HDRi Maps with RAY.HDR technology are perfect for automotive rendering. With IBL, 3D designers creating automotive renders can import the lighting conditions from iconic locations like Bixby Bridge or the Utah Salt Flats effortlessly, adding this lighting data to their virtual vehicle models and backplates to achieve a realistic render.

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.
Whether they're creating a brilliant new design that needs dramatic and unusual lighting or they're designing something utilitarian and need realistic and understated lighting, the right HDRi Map can provide this flexibility through IBL.

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.
In many cases, the visuals they choose come from an HDRi Map. This also allows them to use the IBL data embedded in the scene to light the actors and props accurately, ensuring that they match with the background. 
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.
Of course, 3D designers can also try multiple HDRi Maps in order to find the perfect lighting for the scene. 
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.
Some 3D designers turn to sites like Polyhaven to find HDRi Maps. That’s a great choice for many designers, and their maps are free, but their collection is on the smaller side, so it can be harder to find exactly what you're looking for.
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.
We also created our proprietary RAY.HDR technology specifically with image-based lighting in mind. RAY.HDR provides an unparalleled level of embedded IBL data in each HDRi Map, ensuring that 3D designers have maximum flexibility for their renders. That’s why big brands like Mercedes, Honda and Aston Martin choose to work with us.
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.
Check out our free plan or subscribe to a plan today to start using IBL in your own 3D design workf

Author

  • Randal Cumming

    CEO

    Cumming has more than two decades of experience capturing, creating, and transforming product offerings and workflows for clients across the globe. As the CEO of CGI Background, Cumming leverages his institutional knowledge and experience to help businesses plan and execute interactive, 3D digital strategies that increase consumer engagement and achieve revenue growth goals.