Houdini . Nodes Geometry nodes

MC_IvyTaming_Core geometry node

MC_IvyTaming_Core is the core node of the package IvyTaming aim to to grow,style and animate an ivy

Get Started

Installation And Licencing:

Tutorial :

Basic setup:

Warning

MC_IvyTaming_Core only fully works with MC_IvyTaming_GeoGuide as input

Inputs

input 1

seed points

input 2

Mesh (from output 1 of MC_IvyTaming_GeoGuide)

input 3

VDB distance field (from output 2 of MC_IvyTaming_GeoGuide)

input 4

Guide curves (from output 3 of MC_IvyTaming_GeoGuide)

Parameters

Global parameters

Iterations

Number of life cycles (age/size of the ivy)

Step Size (Global Scale)

Globaly scales the ivy

Random Seed

Global random seed for the ivy.

Use Mask

Enables the input mask which prevent the liana to grow in black areas, grey value increase the probability of death

Use Guides

Enables the input guide curves. The guide curves forces the liana to follow them. The strength is setted by the "GuideFollow" parameter value

Liana

Min Thickness

Liana thickness depends of it’s age. The minimum thichness set the thickness of the most recent branches (tips)

Max Thickness

The maximum thichness set the thickness of the oldest branches (roots)

Wall Offset

Distance between the liana and the surface.

Avoid Liana Collisions

By checking this paramater you avoid collisions of the liana. You can choose between two algorithms: Stop or Avoid

Collision Methode

Stop

Stops the growth when a liana tip is too close of a branch

Avoid

Makes a liana tip changing is direction when too close of a branch

Guide Follow

Sets the guide curves strength for branches

Guide Follow Main

Sets the guide curves strength for the main branch

Branching Min Distance

Minimum steps between two branches.

Branching Probability

Probability of generating a branch at each step considering the branching min distance.

Max Dist Out Of Surface

When the liana goes out of the surface after this value the growth stops.

Note

Tropism

At Each iteration a new direction is calculated for each liana tips. The new direction is a vector resulting of the normalized sum of all weighted tropisms.

Vector NewDirection = normalize ( GravityEffect x GravityVector + SunEffect x SunVector + …)

Previous Dir Effect

The effect of the previous setted direction. In most cases keep it 1.0

Gravity Effect

Sets gravity power. Gravity only acts when the liana isn’t sticked to the wall

Sun Effect

influence of the sun direction in the growth (up by default). If you use a custom sun object it will follow its direction.

Surface Attraction

how much the liana is attracted by the surface of the object on which it grows.

Randomness

how much chaos in the liana growth.

Off The Wall Tendancy

how much the liana tends to go out of the surface of the object on which it grows.

Spread Angle

Angle in degrees between 2 branches.

Leaves

Remove Leaves Collisons

When checked it removes leaves that collides by an iterative process.

The most problematic leaves are deleted first then collision detection checks collisions one more time and so on… The collision step parameter is involved in the number of iterations: low values = slower but more leaves, high values = faster but less leaves.

Warning

When using custom shapes for leaves use custom leave LD with very few polygons for faster calculation When you create a custom leaf the LD version MUST NOT TOUCH THE ORIGIN else you’ll get no leaves as a result ( collision with stem)

Collision Step

The most problematic leaves are deleted first then collision detection checks collisions one more time and so on… The collision step parameter is involved in the number of iterations: low values = slower but more leaves, high values = faster but less leaves.

Leaves Frequency

Increase or decrease the number of leaves.

A value of 0 = one leaf for each liana point.

A value of 1 = two leaves for each liana point.

A value of -1 = one leaf every two liana points.

etc…