When building virtual reality or other applications, there are a number of core topics that are critical to understand. One of those topics is the lighting you create within your Virtual Reality environment. Without the correct lighting, your scene will not look right and the experience will be less than stellar for your users.
In this article, you'll learn about five different light approaches for your virtual worlds. You'll learn what each type is, why it is important, and how it differs from the others. The five styles are:
- Ambient Lighting
- Directional Lighting
- Point Lighting
- Spot Lighting
- Area Lighting
The rest of this article will provide you with an overview of each of these lighting styles.
Ambient Lighting in Virtual Reality
Ambient lighting is the base amount of lighting that is included within your virtual environment. You will generally apply ambient lighting at a minimum lighting level so that objects will be seen. Without ambient light, it is likely your scenes will be in total darkness, without colors, shadows, or with the possibility that objects could be indistinguishable. Of course, this assumes you are using no other lighting source.
In Figure 1, you see a simple Unity Scene with ambient lighting that allows you to see a cube and a sphere.
Figure 1: Ambient lighting in Virtual Reality
Directional Lighting in Virtual Reality
A main light source often used in virtual reality scenes is directional lighting. Directional lighting allows you to shine a light on a scene in much the same way the sun or a flashlight would shine. Because the light is coming from a "source," assets within the virtual environment will be able to cast shadows as well as be lt brighter on those areas facing the light direction. Directional lights are often used to help show or emphasize the 3D nature of elements within a scene.
One of the key ways that directional lighting differs from ambient lighting is that directional lighting comes from one direction, whereas ambient lighting would appear to come from everywhere. In Figure 2, you see the same cube and sphere from Figure 1 with a directional light added to the scene. As you can see, shadows are now rendered along with the objects!
Figure 2: Directional lighting in Virtual Reality
As mentioned, the key characteristic of directional lighting is that it shines in one direction. The brightness of a directional light remains the same along the entire ray.
Point Lighting in Virtual Reality
Another type of lighting in Virtual Reality is point lighting. Point lighting operates similarly to a light bulb. The light begins at a specific source, but instead of radiating in one direction, it shines in multiple directions. Additionally, the further you move away from the light source, the dimmer the light shines.
Figure 3: Point lighting in Virtual Reality
Spot Lights in Virtual Reality
A spot light operates similarly to a point light; however, it is limited to a cone shape from the source instead of shining in all directions. As with a point light, the light will get dimmer the further it gets from the source. Additionally, a spot light will shine brightest from the center of the light source and will defuse at the edge of edge of the spotlight's cone shape.
Figure 4: Spot lighting in Virtual Reality
Area Lights in Virtual Reality
A final type of lighting that I'll mention in this article is area lighting. Area lighting is similar to a point light in that it will shine in all directions; however, it comes from one side of a defined area. A defined rectangular area is where the light starts from, and it illuminates out from one side of the defined area for a given range. To some extent, this is similar to the light coming from a flat screen television, but with a limited range depending upon the intensity of the light.
Figure 5: Colored area lighting in Virtual Reality
Even though most developers like to focus solely on the coding, if your focus is gaming or Virtual Reality, building the graphics are going to be a critical component as well. With today's virtual reality application development, you will find that lighting can be the difference between an amateur and a professional appearance and result.
The first step to doing great lighting is to understand the options you learned about in this article. By applying one or more of the various types of lighting, you can really make your Virtual worlds shine—both figuratively and literally!