Glossary - An Introduction to Computer Graphics for Artists - page 303

Left-hand Rule A rule to defi ne orientation of the three global axes. To visual-
ize this rule, extend the left index fi nger straight up, the middle fi nger towards
your right, and your thumb straight towards your chest. In this confi guration,
your middle fi nger is the X-axis, the index fi nger is the Y-axis, and your thumb
is the Z-axis.
Legal UV space All coordinates between the numbers 0, 0 and 1, 1.
Lens curvature A quality of lenses that affects how refl ected light is received. The
greater the degree of curvature, the greater the degree of distortion, but also the
more detail is received.
Light A virtual entity used to calculate the effect of casting photons of given attri-
butes from a given location.
Linear Measurement A dimension derived from two points only.
Linear Perspective A method for projecting the image of three-dimensional sub-
jects onto a two-dimensional plane.
Local Axis An axis defi ned within an object's attributes.
Local Origin The origin of a given object.
Locked Normals A condition where the normals of a polyset no longer react to
lights in a scene because a lighting calculation already performed on it, usually
in another application, has been baked into the object, preventing it from responding
to new lighting conditions.
LOD Acronym for Level of Detail.
Loft To create polygons or surfaces by extension of existing faces or curves, usually
by a specifi ed distance or from one curve to any number of other curves arranged
in sequence.
Manifold Geometry that may be unfolded fl at without any overlapping part
Mapping The process of creating matching topologies between different elements,
usually used to describe attaching UVs to polysets.
Margin of Error An amount of deviation from a target that is considered acceptable,
or as if no deviation was made.
Master Design Document A document intended to contain all information perti-
nent to the design of a particular thing or group of things.
Material A defi nition intended to simulate the appearance of different substances.
Material Schedule A description, in table form, of substances and the objects to
be made from them.
Measurement A measured dimension.
Mechanical A type of object that is man-made and usually built of numerous mov-
ing parts.
Memory A physical repository for storing computer generated data.
Mercator Mapping A UV layout that imitates the projection type used for globes
that have been cut into elliptical strips joined at the equator. This is known as
Mercator projection after the cartographer Mercator, who fi rst used it.
Merge To fuse two or more things into one.
Misaligned A condition where objects that are meant to be oriented relative to
each other or a common reference are not so oriented.