Color is involved in all aspects of our lives. Color identifies, sets objects
apart, and brings reality to all existing matter. Light is energy that is
necessary for color perception.
LIGHT
Light is born of colors. The sun creates a vast combination of visable colors
known as the color spectrum. With the use of a prism, we can see light broken down into each spectral color band. The order of visible colors is as
follows: red, orange, yellow, green, blue and violet. Since light is energy
and color is light, color is also energy. Energy can be measured. According
to Sir Isaac Newton, these visible bands of energy have different wavelengths. Red has the longest wavelength on one end of the color spectrum, while violet has the shortest wavelength of colored light on the opposite end.
Light can be either direct light, such as the light shining from the sun, or
reflected light, i.e. light reflected off the moon.
ADDITIVE AND SUBTRACTIVE COLOR
When the human eye perceives color, it is in one of two primary forms, either additive color or subtractive color. These primary color forms can produce all visible colors. When looking at direct light we are seeing color as an additive phenomena. The light and color from your monitor is shinning
directly at you. Video monitor colors Red, Green and Blue (RGB) are additive.
These color wavelengths can be added together and overlapped to produce
different colors. For example, Green + Blue = Cyan, Red + Blue = Magenta,
Red + Green = Yellow. Mixing Red, Green and Blue together will produce White.
Subtractive color is seen as the color reflected off an object, i.e.
moonlight. When looking at the moon, we are seeing those wavelengths of
sunlight that haven't been absorbed by the moons surface. This is true of all
earthbound objects as well. A sweater that appears to be red to the observer, is in reality absorbing all the color wavelengths of the spectrum except red.
Subtractive color primaries are used in printing. If we wish to see the color
red printed on a page, the ink must absorb (subtract) all other colors except
red. Subtractive colors are Cyan, Magenta and Yellow (CMY). CMY wavelengths can subtract (absorb) other wavelengths produceing different colors as well. For example, Yellow + Magenta = Red, Magenta + Cyan = Blue, Cyan + Yellow = Green. Mixing Cyan, Magenta and Yellow together will produce Black.
COLOR WHEEL/COLOR CUBE
Color, as described by the design arts, represents the spectral band of colors
in two forms. First, as a circular format where red adjoins the violet end of
the spectrum. This is called a color wheel. The colors will be found to
oppose one another. These opposite colors are termed complementary colors.
The RGB colors are compliments of the CMY colors and vice-versa.
Second, as a color cube, with white and black on opposite corners and red,
magenta, blue, cyan, green and yellow on the remaining corners. TARGA 16 has 32 colors between any two corners of the cube. Between red and black there are 32 colors and between green and yellow there are 32 colors. Since a cube has height, depth and width, the maximum color display is 32,768 colors (32 x 32 x 32 = 32,768). TARGA 32 has 256 colors between any two corners of the cube. Its maximum display of colors is 16,777,216 (256 x 256 x 256 = 16,777,216).
An expanded explanation of the color cube concept may be found in the
documentation that accompanies the Lumena/Oasis paint software product.
HUE, SATURATION & VALUE (HSV)
Color is the most complex of design elements and has other characteristics
such as hue, saturation and value that need to be defined.
HUE: The name of a color or pigment, i.e. red, yellow, cyan. Using standard
imaging software, hue is described in degrees, based on the color wheel.
Think of it as pie, black and white are in the center with all pigments
surrounding them. For example, red is on the right side of the wheel, or pie
at O degrees, yellow would be at 90 degrees, green at 120 degrees, cyan at 180 degrees, etc., as you go around the wheel.
SATURATION: The amount of white in a pigment. Imagine a slice from the color wheel pie, as you move the pigment or hue from the outer edge towards white in the center, the pigment color decreases. At O% saturation you have white. At 100% saturation you have a pure hue.
VALUE: The amount of black in a pigment. Imagine the pie wedge again. As
you move the pigment towards black in the center, its brightness or value
decreases. At O% value you have black. At 100% value you have a pure hue.
See your paint software documentation for a further explanation of RGB, CMY
and HSV.
COLOR PIXELS
The French Impressionistic painters of the 1870's understood how the scenes we view in our environment are shown as points of pure color. This principle can be seen today by looking closely at any color television or color monitor.
When viewed closely the picture seen on the screen is made from thousands of tiny colored dots. When viewed from a distance our brain blends these dots and they are then perceived as a cohesive image.
Computer graphic technologies have expounded upon this impressionistic
principle. The images that one sees when using computer video imaging
software, validates this principle. These images are made up of hundreds of
tiny "pixels" (abreviation for "picture elements"). Each pixel is composed of
an individual color. As was demonstrated by the Impressionists, the
combination of these individual colors or pixels yields the true scenes of
reality. It is this real view of life that we want to duplicate in our
imaging.
ImageCELs ¿ are, therefore, made of many pixels. These pixels are arranged in such an order as to give the appearance of a specific surface or object
texture in our environment. The colors of textures or objects are true
representations of reality. The color of these images, of course, can be
changed to create a desired effect.
Environmental textures, whether man-made or natural are impressions of
reality. Using ImageCELs ¿ palette of impressions, the artist can now create reality with ease!
Perspective is defined as a technique for representing three-dimensional
objects and depth relationships on a two-dimensional surface. Perspective is the truest representation of what our human eye really sees.
When designing a picture that needs to project true reality, perspective
should be used. Perspective creates depth and brings textures and objects to
life. It creates a spatial experience that can be understood immediately.
Before using ImageCELs ¿ to develop perspectives with your painting or rendering software, there are Basic Elements of Perspective and Basic Perspective Characteristics that should be understood.
BASIC ELEMENTS OF PERSPECTIVE
The Basic Elements of Perspective are as follows:
STATION POINT (SP): The position and orientation of the observer's eyes. All
perspectives are based on the position of the observer, their distance from
what is viewed and the angle of view.
CENTER OF VIEW (C): The central line of vision from the station point to the
horizon line. The center of view is always perpendicular to the horizon line.
HORIZON LINE (HL): A line where all horizontal lines appear to vanish. The
horizon line is perpendicular to the center of view and is at the same height
as the station point.
CONE OF VISION:A 60 degree angle where everything important in the picture
should lie within, otherwise excessive distortion can occur. This 60 degree
angle is comprised of 30 degrees to the right of the center of view and 30
degress to the left of the center of view.
GROUND PLANE (GP): The horizontal reference plane where vertical measurements are taken. The height of the horizon line above the ground plane equals the same distance from the station point to the ground plane.
VANISHING POINT (VP): All parallel lines, except those parallel to the
horizon line, appear to converge to a common point. All parallel horizontal
lines appear to converge to a vanishing point on the horizon line. All
parallel lines sloping downward and away from the station point have their
vanishing point below the horizon line (i.e. stairs going down). All parallel
lines sloping upward and away from the station point have their vanishing
point above the horizon line (i.e. stairs going up). All lines parallel to
the horizon line do not converge.
POINT OF VIEW: As the eye of the observer (SP) moves up or down, the horizon line and the vanishing points on it move up or down with it.
ANGLE OF VIEW: The orientation of the object, line or surface to the
observer's line of sight (SP) or center of view. Is the observer (SP) looking
upward or downward at the subject? This angle of view also affects the degree of foreshortening. The more frontal a plane can be seen, the less it needs to be foreshortened, such as a one-point perspective. Angle of View can be divided into two (2) catagories, one-point and two-point perspective:
ONE-POINT PERSPECTIVE: Only the frontal plane of a surface/object
is seen at the center of view. All parallel lines converge to one
central vanishing point which is at the center of the plane and at
the center of view. These pictures tend to be more symmetrical and
static.One-point perspective stops a moment in time and space.
Reality, however, is rarely like this. One-point perspective works
well for showing indoor interior designs.
TWO-POINT PERSPECTIVE: Two planes of a surface/object are viewed by
the observer (SP) at the center of view. A vanishing point has been
established for each plane. This type of perspective is most widely
used. It creates a more dynamic picture giving an image a more
natural view. Outdoor images are excellent for expressing two-point
perspective.
BASIC PERSPECTIVE CHARACTERISTICS
There are four (4) Basic Perspective Characteristics as briefly discussed in
the chapter titled 7-OUTLINE. These characteristics must be shown when
imaging one-point or two-point perspectives so that the desired results are
obtained. These are:
1. OVERLAPPING OF FORMS: The surface/object that is the closest to the
station point appears to block out or overlap what is behind it, leaving
only a portion of the background in view.
2. DIMINUTION OF SIZE: As the station point looks towards the horizon line,
objects and surfaces get smaller in size. Vertical object distances from
one another also appear to come closer together as they recede towards
the vanishing point(s) (i.e. telephone poles).
3. CONVERGENCE OF PARALLEL LINES: Parallel lines that recede from the
station point appear to converge toward a common vanishing point(s).
4. FORESHORTENING: Lines perpendicular to the observer's (SP) line of sight
appear to diminish in length as they are rotated away from the station
point. As the vanishing point moves farther away from the station point,
the horizontal lines flatten out, the perspective depth is compressed,
more plane surface/object is seen and the more foreshortening is
necessary to achieve true perspective.
Knowing the Basic Perspective Elements and Characteristics anything can be
designed simply and easily. To add the finishing touches of realism a few
points should be made regarding light, shadow and shade.
It was found through careful analysis that the key characteristic required in
an object is foreshortening. This adjustment was made when the image library was formed, but awareness of this is helpful for the correct use of the objects.
What this means is that every scene (or image) is viewed relative to the
observer's station point (SP). A station point is the position and
orientation of the observer's eyes. You typically stand on the ground
(ground plane) and "look up" at trees. You "look at" (on the same level)
other people and you "look down" on chairs before you sit. When "looking up"
at a tree you are partially seeing its underside, you are said to be inferior
to the object. ImageCELs ¿, that normally occur above the level of sight
(horizon line), are foreshortened longitudinally toward this inferior
perspective (assuming a 5-1/2 foot horizon line with a mean distance of +/- 25 feet to maintain the optimum visual cone of 60 degrees).
Elements that you "look down" upon are foreshortened the other direction, so
that you are superior to the object. The mean distance for these objects
tends to be 15 feet from the station point. All other objects that are level
with the horizon line are 20 feet from the station point.
Another factor is the objects perspective relative to the observer's center of
view. For this image library, objects are defaulted to a straight forward
center of view. If your paint software has warping and perspective abilities,
you may create the needed lateral foreshortening when appropriate. Rendering software will perform these calculations automatically.
LIGHT, SHADOW & SHADE
Space is perceived because of the way light reveals it. Assume for discussion that all the sun's rays are parallel and that when light is mentioned it is assumed to be direct light, not indirect or reflected light.
LIGHT: A condition on a surface/object that is illuminated by the sun or
other source of illumination, i.e. indoor lighting fixture. When designing an
image, the first thing that must be determined is the angle of light.
ImageCELs ¿ have been developed with the light or sun angle over your left
shoulder. Therefore, all shadows will appear to be below and along the right
edge of the texture/object. This can be changed by the user if desired.
SHADOW: A texture/object that would be in the light, except the light is
blocked by an interim mass. Light and shadow can occur on the same
texture/object. A shadow's length and angle will vary according to the lights horizontal and vertical angles to the texture/object. Shadows can be
perpendicular to the texture/object or they can be parallel, depending on the
angle of light.
Perpendicular shadows are not always the same length as the texture/object due to the light angle, but parallel shadows are usually the same length as the texture/object height. When a parallel shadow hits a wall or texture/object it becomes perpendicular and travels up the wall or texture/object at an angle towards the shadow casting texture/object. A shadow must change direction at every corner of a shadow casting texture/object and all shadow lines must be parallel to one another.
SHADE: A texture/object that is turned away from the angle of light. It
cannot be lit by direct light. Shade and shadow cannot occur on the same
surface, although they exist together. Whenever there is shade there will be
a shadow somewhere.
After all appropriate areas have been shadowed and shaded, re-check the image for overall appropriateness, consistency and perspective.
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