1. Shade & Shadow Figure 1-3, Page 11
Shades are surfaces facing away from sun light
Shadows are surfaces darkened by objects blocking light source.
Shape of shadow is determined by shape of casting object

2. Rules of Shade and Shadow
Analyze view to determine direction and angle of sun
Determine which surfaces are in shade and which receive light
Because the direction of sunlight is constant in your drawing, all shadows caused by the sun will fall in the same direction.
In plan they are parallel and in perspective view they will all converge to the same vanishing point

3. Rules of Shade and Shadow Continued
Shadows of vertical edges that fall on vertical surfaces are also vertical
Horizontal surfaces cast shadows that are parallel to themselves whether they fall on the ground or on nearby vertical surfaces.
Parallel lines converge to a common vanishing point. An exception to this is when a nearby vertical surface is perpendicular to the direction of the horizontal surface. Then the shadow resolves itself back to its casting edge.

4. Casting Edges
Divide light areas from shaded areas. May be visible or may be blocked by other objects. Must imagine drawing as transparent to locate all casting edges.

5. Illumination Figure 1-4, Page 13
Engineering term referring to non-sunlit lighting
Not necessary to illustrate every light source of an interior space. A few general lighting directions are adequate
You must first determine whether a space has or will have major sources of natural or artificial light.

6. Illumination Continued
Surfaces facing away from light source are in shade so they will be darker
The farther away a surface is from a light source the darker it will be, the closer the lighter
Gradients: All larger surfaces are gradients of value and color. Gradation creates visual cues that provide overall illumination and indicate its sources

7. Illumination Continued
Interior shadows should not be as dark or have as much contrast as exterior shadows. Keep them subtle. You can darken them later, but it is difficult to lighten them.
Interior edges are almost always diffuse.
Interior shadows are almost always gradients, darker at the core and lighter as they move away from the object

8. Illumination Continued
Shadows anchor objects to the surfaces they touch. Objects will appear to float without proper shadows.
Because of multiple light sources in interiors, objects will cast multiple shadows.
Each shadow should fall away from the general direction of the light source to which it corresponds.

9. Local Tone Figure 1-7, Page 16
Means the intrinsic lightness or darkness of an object.
Materials with different local tones will have shadows that correspond to them.
Light objects have lighter shadows and shaded areas than darker ones.

10. Chiaroscuro: Light/Dark
Makes objects appear 3 dimensional.
In black & white drawings you can have white and black and a range of grays, but not in color drawings.
Shadows in color drawings are colored, usually a darker shade of the local color.

11. Color of Shade and Shadow Figure 1-8, Page 17
Sometimes shades and shadows will appear to be different colors than a darker version of the object’s local color.
This happens when shaded or shadowed surfaces face a source of colored light.
This light may be direct or reflected from a nearby form that is itself brightly lit.

12. Color of Shade and Shadow
Common example of colored shadows: shaded surfaces of buildings appear bluish from the reflection of blue sky.
Most apparent on neutral materials like concrete which looks bluish or purplish in shade and orange-ish or pinkish in light.

13. Simultaneous Contrast
Opposites increase the intensity of each other. White looks whiter against black and vice versa.
Color against a neutral looks brighter
Colors automatically produce an “after image” in their complementary hue. Green makes red look brighter and vice versa.

14. Gradation Figure 1-9, Page 18
Most flat surfaces do not appear uniformly colored or illuminated. Instead they seem to gradate from one color or value to another.
Most apparent on large surfaces like walls, ceilings and floors but occurs on all objects to some degree.
Occurs because of proximity to light source and light and colors reflected on objects

15. Gradation Continued Gradual on matte surfaces
Sharper with increasing mirror-like reflection on polished surfaces
Example: concrete shows more even gradation than brushed stainless steel
Makes surfaces appear more realistic and dynamic

16. Gradation Continued
Forcing the shadow: means to make a shadow darker where it meets its light boundary, and lighter where it meets its dark boundary.
Creates brilliancy.
Can also do this with foreground and background elements. Background can be darkened and cooled and foreground can be lightened and warmed where they meet.

17. Multiplicity of Color Figure 1-10, Page 19
Local color is similar to local tone, but with hue instead of value.
Generally we do not perceive local color. What we see is a visual average of many colors or medial mixtures.
Medial mixtures and light refraction create multiple colors in our perception

18. Multiplicity of Color Continued
Optical mixing is when small dabs or dots of various colors are grouped together and optically mixed, and perceived as a singular color. Creates a sense of air and sparkle
Color mingling is mixing one color through another color, but letting one hue dominate. Color mingling allows for more richness and interaction of colors.

19. Simultaneous Contrast Gradient

21. Rules of Shade and Shadow Continued
Next determine how long you want flagpole shadow to be. Take a line from the top of the flagpole to the end of the flagpole shadow to determine the sun’s angle. This depends on how high or low the sun is, but must remain consistent throughout the drawing.

22. Luminosity