BASICS: AREA LIGHTS
Discover how to use Area Lights for added realism
If you’re new to CGI, you may feel that there are far too many tools to choose from in a dizzying array of software. This series aims to break everything in CGI down to the very basics, so that every artist can be armed with the knowledge of which tool is best. This time we take a look at lighting with Area Lights.
Creating realistic, convincing lighting used to be one of the hardest things to achieve in CGI. However, with the latest generation of render engines, combining speed with the ability to work with image-based lighting, a lot of the work has already been done.
Thinking like this, however, discards many of the creative possibilities that creating your own lighting setup allows (just ask any commercial photographer).
One of the key tools for creative lighting in a CG artist’s arsenal is the Area Light. The Area Light comes with every major 3D application as one of the main light objects, and what makes it special is that it is the light type which most closely resembles a real-life light source.
It is only in the past few years that Area Lights have become dominant as the primary light tool for many artists, as they used to have a high computational price in render time and they had a tendency to be noisy.
Recently though most advanced render engines can handle Area Lights with aplomb. Features that make Area Lights unique, such as the ability to easily see the shape of the light object and the ability to easily control light intensity by moving or resizing an Area Light, are near identical to those used in a photographic studio.
As Area Lights are so similar to studio lights it also means that learning the techniques of professional photographers for a particular look is easier with Area Lights than it would be with other light objects – especially as Area Lights can be visible to create interesting reflections for product shots.
Mastering the use of Area Lights has always benefitted any CG artist, and the power they offer is no longer hampered by hardware limitations.
01 ADD AN AREA LIGHT
Area Lights are normally a default option in the lighting menu for most digital content creation applications. An Area Light differs from other light types in that the Area Light icon (normally) gives a representation in the viewport of the size and direction of the Area Light. Naturally this makes it much easier to position the Area Lights in natural ways, which is especially helpful when trying to match lighting setups from a real studio or scene location.
02 POSITION THE AREA LIGHT
Area Lights behave like lights in the real world in that when they are moved away from the object being lit, the amount of light that they produce diminishes. This is due to the light falloff, as an Area Light is designed to be as physically accurate as possible. Most digital content creation applications allow the falloff to be changed to a ‘Linear’ falloff, which controls the amount of light over a distance, or off all together, which can be useful if the Area Light is needed as a constant light source.
03 AREA LIGHT SHADOWS
Another factor to be aware of is that the size of an Area Light determines the type of shadows it creates. A small Area Light that is five times more powerful yet five times smaller than an Area Light positioned at the same distance from the subject may give the same light level, but it will create much sharper shadows than the larger Area Light. Again this is analogous to real-world lighting setups, and can help create complex light setups quickly.
04 USE IMAGE-BASED AREA LIGHTS
Some 3D applications and third-party render engines will also allow textures to be applied to Area Lights. This can be really useful for creating light types using bitmap images that mimic studio lights, or to add more complex colour output options. For example, using a ramp (or gradient) to create a two-colour Area Light, which can be animated if needed to, allows one Area Light to create a wide range of lighting scenarios within a scene. •