Trunk segment is the simplest building block of the trunk.
Bough is a branch that is attached to the trunk.
Bough segment is the simplest building block of the bough.
Branch is that branch that is attached to a bough or to another branch.
Branch segment is the simplest building block of the branch.
Twig is the terminal generation branch that carries leaves.
Twig segment is the simplest building block of the twig.
Crown center is that point on the trunk where the longest bough stems out.
Phyllotaxy defines the arrangement of branches and leaves that grow along the same, parent branch. These arrangements have profound impact on the tree form.
Stem segment is the simplest building block of the leaf stem.
Trunk and Bough Parameters
Random Seed sets the randomization pattern for a tree model. It allows TREE to generate a number of different instances of the same tree type. Since it affects the values of all parameters, Random Seed is accessible on all four modeling levels.
*****
Trunk Height sets the height of the trunk. On double click the Trunk Height button, the following dialog box appears:
 
Winding offset sets the winding amplitude of the trunk.
Winding step sets the winding period of the trunk.
Segment length sets the length of the trunk segment.
Trans. resolution sets the number of polygons (transversal resolution) for each cylindrical segment of the trunk.
Model check box allows you to choose whether to model or not to model the trunk.
*****
Bottom Height sets the position of the first bough along the trunk.
*****
Crown Center sets the position of the longest bough along the trunk.
*****
Bough Length sets the length of the longest bough. On double click the Bough Length button, the following dialog box appears:
 
Min. length sets the minimum length for boughs.
Winding offset sets the winding amplitude for boughs.
Segment length sets the length of the bough segment.
Trans. resolution sets the number of polygons (transversal resolution) for each cylindrical segment of the bough.
Model check box allows you to choose whether to model or not to model the boughs.
*****
Length Change button brings up the following dialog box:
 
Upper convexity sets the pattern of bough length change from the crown center to the top of the trunk.
Lower convexity sets the pattern of bough length change from the crown center down to the bottom of the tree crown.
*****
Bough Angle sets the bough-to-trunk angle of the first bough along the trunk. On double click the Bough Angle button, the following dialog box appears:
 
Top bough angle sets the bough-to-trunk angle of the last (top) bough along the trunk.
*****
Angle Change sets the pattern of bough angle change along the trunk. On double click the Angle Change button, the following dialog box appears:
 
Angle change starts at sets the height along the trunk at which the bough angle starts to change.
*****
Bough Curving sets the pattern of curving for boughs. On double click the Bough Curving button, the following dialog box appears:
 
Curving change sets the pattern of bough curving change along the trunk.
Lock to length, when checked, causes the amount of curving to vary for boughs with different lengths, the curving is dependent on the bough’s length. If it is not checked, all boughs have the same curving factor.
*****
Bough Density sets the extent of population for boughs. On double click the Bough Density button, the following dialog box appears:
 
Max. group of sets the maximum number of boughs in the same group.
Random offset sets the extent of deviation in the number of boughs per group from the maximum number.
Pruning sets the amount of boughs to be pruned.
*****
Bough Twist sets the angle of rotation of the first bough around the trunk.
Branch and Twig Parameters
Random Seed sets the randomization pattern for a tree model. It allows TREE to generate a number of different instances of the same tree type. Since it affects the values of all parameters, Random Seed is accessible on all four modeling levels.
*****
Branch Length sets the length of the longest branch relative to its parent branch. On double click the Branch Length button, the following dialog box appears:
 
Min. length sets the minimum length for branches.
Winding offset sets the winding amplitude for branches.
Segment length sets the length of the branch segment.
G1 trans. resolution sets the number of polygons (transversal resolution) for each cylindrical segment of the first generation branch.
G2 trans. resolution sets the number of polygons (transversal resolution) for each cylindrical segment of the second generation branch.
G3 trans. resolution sets the number of polygons (transversal resolution) for each cylindrical segment of the third generation branch.
Model G1 check box allows you to choose whether to model or not to model the first generation branches.
Model G2 check box allows you to choose whether to model or not to model the second generation branches.
Model G3 check box allows you to choose whether to model or not to model the third generation branches.
*****
Length Change sets the pattern of branch length change for a succession of branches of the same parent branch.
*****
Branch Angle sets the maximum branch-to-parent branch angle for branches.
*****
Angle Change sets the pattern of branch angle change for a succession of branches of the same parent branch.
*****
Branch Curving sets the pattern of curving for branches. On double click the Branch Curving button, the following dialog box appears:
 
Curving change sets the pattern of branch curving change across the tree crown.
*****
Branch Density button brings up the following dialog box :
 
G1 density sets the extent of population for the first generation branches.
G1 growth starts at sets the position of the first branch along its parent branch for the first generation branches.
G1 pruning sets the amount of the first generation branches to be pruned.
G2 density sets the extent of population for the second generation branches.
G2 growth starts at sets the position of the first branch along its parent branch for the second generation branches.
G2 pruning sets the amount of the second generation branches to be pruned.
G3 density sets the extent of population for the third generation branches.
G3 growth starts at sets the position of the first branch along its parent branch for the third generation branches.
G3 pruning sets the amount of the third generation branches to be pruned.
*****
Twig Length sets the average length for twigs. On double click the Twig Length button, the following dialog box appears:
 
Random length sets the extent of deviation in lengths from the average twig length.
Winding offset sets the winding amplitude for twigs.
Segment length sets the length of the twig segment.
Trans. resolution sets the number of polygons (transversal resolution) for each cylindrical segment of the twig.
Model check box allows you to choose whether to model or not to model the twigs.
*****
Twig Angle sets the average twig-to-parent branch angle for twigs. On double click the Twig Angle button, the following dialog box appears:
 
Random angle sets the extent of deviation in twig-to-parent branch angles from the average twig angle.
*****
Twig Curving sets the pattern of curving for twigs. On double click the Twig Curving button, the following dialog box appears:
 
Curving change sets the pattern of twig curving change across the tree crown.
*****
Twig Density sets the extent of population for twigs. On double click the Twig Density button, the following dialog box appears:
 
Pruning sets the amount of twigs to be pruned.
*****
Phyllotaxy button brings the following dialog box:
 
 
stands for Phyllotaxy 120.
If BR1, BR2, BR3, and TW is checked, branches of the first, second, third generation, and the twigs spring from three sides of the parent branch. Each successive branch is rotated with respect to the previous branch for 120°. Phyllotaxy 120 causes branches to grow in all directions thus resulting very often in not so regular crown shapes.
 
stands for Phyllotaxy 180.
If BR1, BR2, BR3, and TW is checked, branches of the first, second, third generation, and the twigs spring from opposite sides of the parent branch. Each successive branch is rotated with respect to the previous branch for 180°. Phyllotaxy 180 tends to spread branches in flat planes facing the sky and produces very often well-ordered crown shapes commonly found in conifers.
COMMENT!
In nature, the trees follow a number of different Phyllotaxy patterns (120 and 180 being very common), and Phyllotaxy is one of the characteristics that differentiates species. Phyllotaxy arrangements are the most apparent on shoots, leaves, and very young branches. As the tree grows, these arrangements deviate more and more to accommodate a variety of impacts from the environment. In order to capture these changes, we have taken the freedom to allow you to set Phyllotaxy patterns on different classes of tree elements independently.
Volume Parameters
Random Seed sets the randomization pattern for a tree model. It allows TREE to generate a number of different instances of the same tree type. Since it affects the values of all parameters, Random Seed is accessible on all four modeling levels.
*****
Trunk Width changes all characteristic trunk widths relative to their respective, current values. On double click the Trunk Width button, the following dialog box appears:
 
Regions along the trunk defines the positions of six, characteristic widths along the trunk.
Width values sliders allow you to set these six, characteristic widths. Each width value and its corresponding position are designated by the same color.
Min. segment length sets the length of the trunk segment.
*****
Branch Width sets the transversal growth pattern for boughs and all successive generation of branches and twigs. On double click the Branch Width button, the following dialog box appears:
 
Min. width sets the minimum width for boughs, branches, and twigs.
Enforce width change enforces transversal growth of the top bough to be the one set by Branch Width. If it is not checked, the transversal growth of the top bough may vary and it depends on the top width of the trunk.
*****
Color button brings up the following dialog box:
 
Dominant color radio buttons allow you to choose red, or green, or blue to be the dominant color for the trunk (branch and twig) palette.
PT1 stands for PALETTE 1 which is the trunk (branch and twig) palette displayed to the right.
TPC stands for Trunk Primary Color displayed to the left. The primary color can be any color in the palette. You choose the trunk primary color by moving the slider attached to the trunk palette.
The three color fields displayed below the trunk palette are the principal tools for composing the trunk palette. If the dominant color is red, the top color field is designated to the green and the middle one to the blue color component. The bottom color field is always designated to the black color.
Each color field enables you to mix chosen amounts of the corresponding color component with the dominant color. The two vertical sliders control the amount of the corresponding color component mixed with the dominant color. The two horizontal sliders define this part of the palette which will be affected by the mixture.
Longitudinal contrast check box activates or deactivates color change along the trunk in longitudinal direction. If active, the trunk color will change from the leftmost color in the palette at the bottom of the trunk to the primary color at the top of the trunk. All successive boughs, branches, and twigs will be affected as well.
Transversal contrast check box activates or deactivates color change along the trunk in transversal direction. If active, the trunk color will change from the leftmost color in the palette to the primary color around its perimeter. All successive boughs, branches, and twigs will be affected as well.
Transversal contrast slider allows you to set the position of the primary color on the perimeter of the trunk.
Foliage Parameters
Random Seed sets the randomization pattern for a tree model. It allows TREE to generate a number of different instances of the same tree type. Since it affects the values of all parameters, Random Seed is accessible on all four modeling levels.
*****
Leaf Type lets you select different leaf forms and different leaf sizes. The leaf forms and their size options conform closely to the forms and sizes of those found in nature. Leaf Type button brings up the following dialog box:
 
 
oblong - as in Chestnut, Laurel Oak - 1 polygon
 
ovate - as in Apple, Beech, Birch, Dogwood, Linden - 1 polygon
 
fan-shaped - as in Ginkgo - 2 polygons
 
palmately compound - as in Horse Chestnut - 5 polygons
 
rounded lobed - as in Japanese Maple - 5 polygons
 
palmately lobed - as in Maple, Sycamore - 5 polygons
 
ovate lobed - as in Oak - 6 polygons
 
lanceolate - as in Willow - 1 polygon
 
ovate with three lobes - as in Hawthorn Maple - 3 polygons
Leaf size lets you select four characteristic sizes of each leaf type.
Flat leaves check box allows you to choose whether to model each leaf as a planar or non-planar object.
*****
Leaf Density sets the extent of population for leaves. On double click the Leaf Density button, the following dialog box appears:
 
Pruning sets the amount of leaves to be pruned.
*****
Stem Length sets the average length for stems. On double click the Stem Length button, the following dialog box appears:
 
Random length sets the extent of deviation in lengths from the average stem length.
Stem width sets the width for stems.
Segment length sets the length of the stem segment.
Trans. resolution sets the number of polygons (transversal resolution) for each cylindrical segment of the stem.
Model check box allows you to choose whether to model or not to model the stems.
*****
Stem Angle sets the average stem-to-parent twig angle for stems. On double click the Stem Angle button, the following dialog box appears:
 
Random angle sets the extent of deviation in stem-to-parent twig angles from the average stem angle.
*****
Stem Curving sets the pattern of curving for stems. On double click the Stem Curving button, the following dialog box appears:
 
Random curving sets the extent of deviation in stem curving across the tree crown.
*****
Phyllotaxy button brings up the following dialog box:
 
 
stands for Phyllotaxy 120.
If checked, the leaves spring from three sides of the parent twig. Each successive leaf is rotated with respect to the previous leaf for 120°.
 
stands for Phyllotaxy 180.
If checked, the leaves spring from opposite sides of the parent twig. Each successive leaf is rotated with respect to the previous leaf for 180°.
Sky sensitive check box allows you to position the leaves across the tree crown with the special sensitivity to the sky (light).
*****
Color button brings up the following dialog box:
 
Dominant color radio buttons allow you to choose red, or green, or blue to be the dominant color for the currently active palette.
PT3 stands for PALETTE 3 which is the foliage palette displayed to the right.
PT2 stands for PALETTE 2 which is the foliage palette displayed to the right.
You choose to work on PALETTE 2 or PALETTE 3 by clicking PT2 or PT3 radio buttons.
FPC stands for Foliage Primary Colors displayed to the left. Each foliage palette has its own primary color assigned to it. The primary colors can be any colors in the PALETTE 2 or PALETTE 3. You choose the foliage primary color for currently active palette by moving the slider attached to this palette.
The three color fields displayed below the foliage palettes are the principal tools for composing the foliage palettes. If the dominant color of the currently active palette is red, the top color field is designated to the green and the middle one to the blue color component. The bottom color field is always designated to the black color.
Each color field enables you to mix chosen amounts of the corresponding color component with the dominant color. The two vertical sliders control the amount of the corresponding color component mixed with the dominant color. The two horizontal sliders define this part of the currently active palette which will be affected by the mixture.
Color spread allows you to assign the two color palettes to different groups of leaves in designated proportions.
Contrast allows you to choose between two patterns of foliage color change across the tree crown. R or random pattern assigns the colors from the designated range to the leaves randomly. D or directional pattern assigns a particular range of shades to a leaf with respect to this leaf’s position on the crown.
