Directionality of light defining surface

This is a series of images representing variations of light on a stucco wall. Notice the differences and how they affect the definition of the surface in B&W.
Early morning, slightly directional but mostly flat light- sun just over the left shoulder.
Same time as above, but camera moves 45% to the right, giving the sun more angle in relation to the wall. Moving around your subject changes your angle of view and the relationship of highlight and shadow.
Later in the day, sun is at a right angle to camera. The light is scraping along the edge of the wall defining every variation in texture. This light is called "directional" or "side" lighting.
Shade. Notice that texture is mostly defined by color variation. Even in shade there are highlights and shadows, but they are less intense, compressing the gray scale.
Shade with bounced (reflected) light from a sidewalk. Notice the added spark of highlight which gives life to the texture and stretches the gray scale out towards the highlights.

The directionality of light defines the look of your image. Walk around your subject and see how light bounces and reflects off of it. An interesting idea must be defined by interesting light.