- Dec 20, 2002
Shadows on Angled Surfaces
Shadows that fall on angled surfaces distort to follow the angles. Earlier in this chapter, the distortion of a tree casts a shadow across the ground and up a wall. The "Rendezvous" image has a shadow that applies this technique to many surfaces simultaneously (Figure 4.55).
Figure 4.55. The "Rendezvous" image has a series of shadows that add drama and give a sense of the time of day.
If you zoom in to the sign on the sidewalk, you see the play of shadows resulting from the chain (Figure 4.56).
Figure 4.56. The shadow that is cast by the chain is broken as it passes over various surfaces.
As with the layer of the tree in the previous example, the layer of the chain is duplicated and filled with black to serve as the Shadow layer. This Shadow layer is duplicated several times because the shadow falls on different elements in the image. Each new element has its own angle.
The first angle requires the Shadow layer to be skewed downward, as shown in Figure 4.57.
Figure 4.57. The Shadow layer is skewed downward.
It is then scaled down (Edit>Transform>Scale) horizontally to make it thinner. The fact that the wooden post, on which the shadow is cast, is at an angle to the light source causes the shadow to shrink. To see the shadow in the area of the wooden post only, the layer of the shadow and the sign are made into a clipping group.
On the lower support bar of the sign, two shadows are added. The first follows the angle of the chain as it is cast on for the upper edge of the board. The angle is similar to the angle of the ground. The second goes through the same transformation as the one on the upper post (Figure 4.58).
Figure 4.58. On the lower support bar of the sign, two shadows are added. The first is straight on for the upper edge of the board. The second one goes through the same transformation as the one on the upper post.
The final shadow on the sidewalk is simply scaled down to make it smaller. A slight Blur filter is applied to soften it, as shown in Figure 4.59.
Figure 4.59. The shadow on the sidewalk is scaled down to make it smaller, and a Blur filter is applied to soften it.