Digital Lighting & Rendering, Second Edition

CHAPTER FOUR: Lighting Environments and Architecture 105

[Figure 4.19]

Finally,  ll light is added to

brighten every surface.

Corners

Corners are the area where light most closely inter-refl ects between walls.

As a result, there should be continuity at the corners, a continuation of

tones from one wall to another, rather than a sudden jump in brightness. If

there were a huge difference between the amount of light on two walls in a

corner, then it would look as if light were not refl ecting between the walls.

Open spaces in the middle of walls tend to be exposed to the most ambi-

ent light bouncing around a room, so areas in the middle of a wall are often

brighter than cracks or corners. Figure 4.20 is a photograph of a real corner,

where you can see the soft progression from brighter walls into darker cor-

ners, and the continuity between the walls and ceiling where they meet.

An alternative approach to darkening your corners is to use negative lighting.

Instead of carefully aiming bounce lights to avoid lighting the corners, you

can use lights with a negative intensity to suck light out of the corners of a

room. To use negative lighting in the corners, you just broadly illuminate

the entire room with fi ll lights, then add lights focused in the corners with

106 Digital Lighting and Rendering

a negative intensity or brightness to darken those areas. The left side of Fig-

ure 4.21 shows how some negative lights are positioned along the corners

of a room. In this case, they are volume lights in Maya, set to emit ambient

but not diffuse or specular, with an intensity of -0.5. The rendered result is

shown on the right, where you can see a soft darkening of the corners.

[Figure 4.20]

A real corner shows darken-

ing and the inter-re ection

of light.

[Figure 4.21] A light with a negative intensity (shown in Maya, left), is positioned along each

corner that needs to be darkened (center), producing a render with darkened corners (right).