Tree

Documentation of the tree components.

Introduction

The Tree cluster provides a series of components that generate parametric diagrams of tree systems, based on research in the stages of tree development. These components offer a powerful tool for understanding and visualizing the complex structures of trees, which have been the subject of extensive study in arboriculture.

Early work on tree development was pioneered by Pierre Raimbault, whose two seminal papers The management of ornamental trees Part 1 Raimbault et al. (1993), Part 2 Raimbault et al. (1995) laid the foundation for analyzing and diagnosing the aerial parts of trees. His framework provided one of the first systematic approaches to describing tree growth patterns and structural organization.

Building on this foundation, Christophe Drénou has refined and advanced the understanding of tree development.(Drénou et al. (2015), Larrieu et al. (2022)) His model condenses the complex life history of trees into four key stages — young, adult, mature, and senescent — offering a more accessible yet rigorous way to represent tree growth and form.

This cluster provides both 2D tree and 3D tree generation components based on the Drénou Model, along with a forest component that considers interactions between trees. Together, they offer users a clear framework for generating parametric diagrams that reflect the major stages of tree development.

Component Usage

Please refer to the following sections for each component from this cluster. While the information is not needed to generate the tree diagrams, information from the Soil, and Root clusters are required to complete the full diagram illustration.

Tree 2D - Drénou Model

This component is used to generate sectional tree diagrams based on the given plane, height and phase.

Param.Abbr.I/OOptionalDescription
PlanePYesBase plane(s) where the tree(s) is drawn.
HeightHNoHeight of the tree.
PhasephaseNoPhase of the tree.
TrunkTTree trunk curves.
CanopyCurveCCA curve on top of the tree that represents its canopy.
SideBranchSBTree side branch curves.
TopBranchTBTree top branch curves.
TreeInfoTinfoInformation about the tree.
Example T1: 2D Tree
This example demonstrates the usage of the Tree 2D component to create a 2D single tree. Note that the examples uses component from the add-on Human to define the width of curves. Users can install this package via the PackageManager in Rhino.

Tree Growth Phases Diagram

Forest 2D

The forest 2d section is an extension of the Tree 2D component, which allows for the automatic adjustment of each tree's width based on its proximity to neighboring trees. By modifying the spacing between trees, users can generate a diagram featuring a series of trees that are precisely adapted to their spatial relationships with one another. This extension leverages the capabilities of the tree component to create a more realistic and dynamic representation of a forest ecosystem.

Example T2: 2D Forest
This example demonstrates the usage of the Tree 2D component to create 2D forest. Note that the examples uses component from the add-on Human to define the width of curves. Users can install this package via the PackageManager in Rhino.

Tree 2D - Raimbault Model(Legacy)

This component is used to generate sectional tree diagrams based on the given plane, height and phase.

Unitary

Non-Unitary

Param.Abbr.I/OOptionalDescription
PlanePYesBase plane or planes in which the tree is drawn, the default value is World-XY unless specified.
HeightHNoInput parameter that controls the height of the drawn tree diagrams.
PhasephaseNoThe growth phase ( 1, 12 ) of the tree, allowing adjustment of the maturity of the tree.
CircumferenceCCircumference ellipses that control the boundary of the tree.
TrunkTCurves that define the trunk of the tree.
CanopyCThe upper limit of the drawn branches of the tree.
SideBranchSBA list of curves that include branches that grow horizontally in respect to the tree trunk.
TopBranchTBA list of curves that grow from the upper portion of the trunk at different phases of tree growth.
BabyBranchBBA list of curves that are drawn to show the development of smaller branches in different phases of growth.
TreeInfoTinfoInformation about the growth of the tree that is used for tree root diagram generation.

Tree Growth Phases Diagram

Forest 2D - Raimbault Model (Legacy)

The forest 2d section is an extension of the Raimbault model component, which allows for the automatic adjustment of each tree's width based on its proximity to neighboring trees.

Example (Legacy): 2D Forest (Raimbault Model)
This example demonstrates the usage of the Raimbault Model component to create 2D forest. Note that the examples uses component from the add-on Human to define the width of curves. Users can install this package via the PackageManager in Rhino.

Tree 3D Composer

This component generates tree objects following the Drénou Model based on the given plane and various control parameters, including tree and trunk size, spread angle, and growth phase. Notably, the output is tree object(s), which require further processing for visualization with the renderer component or for tree interaction with the forest interaction component.

Param.Abbr.I/OOptionalDescription
PlanePYesBase plane(s) where the tree(s) is drawn.
GlobalScaleglobalSYesGlobal scale of the tree.
TrunkScaletrunkSYesTrunk scale of the tree.
SpreadAngleMainangMainYesSpread angle of the primary tree branches.
SpreadAngleTopangTopYesSpread angle of the secondary tree branches (the top part).
PhasephaseNoPhase of the tree's growth. Range: [1,13]. The parameter signifies the tree's growth stage and influences its overall shape.
There are 13 distinct phases, and typical phases include phase 2, 8, 10, and 13. Difference between phases is shown in section below.
SeedseedYesSeed for random number to vary the tree shape.
BranchRotationbrRotYesWhether to rotate the branches sequentially.
DuplicateNumberdupNumYesNumber of top side branches for duplicate branching. Range: [0,3].
IdidYesAn optional id of the tree or tree group, used for selecting trees in the same group in the renderer.
TreeObjectsTree_OutTree objects that can be passed to renderer or interaction components.

Different Growth Phases Diagram

We classify trees into 13 distinct phases, which are grouped into 4 developmental stages: young, adult, mature, and senescent.

  • The young stage includes phases 1 to 4.
  • The adult stage includes phases 5 to 9.
  • The mature stage includes phases 10 and 11.
  • The senescent stage includes phases 12 and 13.
Stage
Young
Adult
Mature
Senescent

Typical Growth Stages

Tree 3D Renderer

This component renders tree objects obtained from the composer component or the forest interaction component. Specifically, it generates tree trunks and branches as curves and organizes tree information.

Param.Abbr.I/OOptionalDescription
Tree ObjectsTree_InPNoTree objects generated to render.
IdidYesAn optional id of the tree or tree group, used for selecting trees in the same group in the renderer.
TrunkTTree trunk curves.
SideBranchSBTree side branch curves (non-split).
TopBranchTBTree top branch and duplicated branch curves (splitted).
TreeInfoTInfoInformation about the tree.

Example T3: 3D Tree
This example demonstrates the usage of the Drénou Model composer and renderer components to create and visualize a single tree.

Forest Interaction

This component simulates interactions between trees within a forest based on spatial relationships, shading effects, and other environmental factors. It helps model tree status, competition, and growth dynamics.

Param.Abbr.I/OOptionalDescription
T -> InteractiontToInteractNoThe collection of tree objects in various species before interaction.
Interaction -> TtAfterInteractThe collection of tree objects in various species after interaction.

Example T4: 3D Forest
This example demonstrates the usage of the forest interaction component to create forests from regular grid points and random grid points.

Tree Energy Canopy

This component uses the trunk and the branches of the 3D tree to generate the energy canopy that can be used for energy analysis. It outputs a mesh-type water-tight volume that can be used as a "shade" for energy analysis.

Param.Abbr.I/OOptionalDescription
TrunkTNoTree trunk curves.
TrunkRadiusT-rYesTree trunk radius, for creating different sizes of trunks.
BranchesBNoTree branch curves.
EnergyVolumeEEnergy volume for energy analysis.

Transmittance

In energy analysis, tree crown density and foliage play key roles in blocking sunlight and heat from reaching the ground. To integrate this feature into the energy analysis, we rely on the control of the transmittance parameter of the canopy mesh in the analysis software.

Figure: A horse chestnut tree, shown with and without leaves. Adapted from Krause (2021).

A guidance for setting the transmittance value for direct solar radiation is given below Konarska et al. (2014):

Tree Crown StateRecommended Transmittance ValueMean of Deciduous Trees
Foliated1.3% - 5.3%2.9%
Defoliated40.2% - 51.9%47.9%

References

Drénou, C., Bouvier, M., & Lemaire, J. (2015). The diagnostic method ARCHI applied on declining pedunculate oaks. Arboricultural Journal, 37(3), 166–179.
Konarska, J., Lindberg, F., Larsson, A., Thorsson, S., & Holmer, B. (2014). Transmissivity of solar radiation through crowns of single urban trees—application for outdoor thermal comfort modelling. Theoretical and Applied Climatology, 117, 363–376.
Krause, P. (2021). Shade trees for better climate in buildings. https://www.uni-stuttgart.de/en/university/news/all/hausbaeume/
Larrieu, L., Courbaud, B., Drénou, C., Goulard, M., Bütler, R., Kozák, D., Kraus, D., Krumm, F., Lachat, T., Müller, J., & others. (2022). Perspectives: Key factors determining the presence of Tree-related Microhabitats: A synthesis of potential factors at site, stand and tree scales, with perspectives for further research. Forest Ecology and Management, 515, 120235.
Raimbault, P., Jonghe, F. de, Truan, R., & Tanguy, M. (1995). The management of ornamental trees. Part 2: management of the aerial parts: principles of modern long pruning. 47(1), 7–38.
Raimbault, P., Tanguy, M., & Bertrand, H. (1993). The management of ornamental trees. Part 1: Method of analysing and diagnosing the aerial part. 45(2), 97–117.