Graphics Reference
In-Depth Information
Basic branching schemes
Structures resulting from repeated application of a single branching scheme
FIGURE 12.9
Branching structures of interest in two dimensions.
Simplifications are made to highlight the information most relevant for computer graphics modeling
and animation.
The structural components of plants are stems , roots , buds , leaves , and flowers . Roots are typically
not of interest when modeling the visual aspects of plants and have not been incorporated into these
plant models. Most plants of interest in visualization have a definite branching structure. Such plants
are either herbaceous or woody . The latter are larger plants whose branches are heavier and more struc-
turally independent. The branches of woody plants tend to interfere and compete with one another.
They are also more subject to the effects of wind, gravity, and sunlight. Herbaceous plants are smaller,
lighter plants, such as ferns and mosses, whose branching patterns tend to be more regular and less
subject to environmental effects.
Stems are usually above ground, grow upward, and bear leaves. The leaves are attached in a regular
pattern at nodes along the stem. The portions of the stem between the nodes are called internodes .
Branching is the production of subordinate stems from a main stem (the axis ). Branches can be formed
by the main stem bifurcating into two equally growing stems ( dichotomous ), or they can be formed
when a stem grows laterally from the main axis while the main axis continues to grow in its original
direction ( monopodial ).
Buds are the embryonic state of stems, leaves, and flowers; they are classified as either vegetative or
flower buds . Flower buds develop into flowers, whereas vegetative buds develop into stems or leaves.
A bud at the end of a stem is called a terminal bud; a bud that grows along a stem is called a lateral bud.
Not all buds develop; nondeveloping buds are referred to as dormant . Sometimes in woody plants, dor-
mant buds will suddenly become active, producing young growth in an old-growth area of a tree.
 
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