Frond generator properties

The Frond generator icon.

Generation

Random Seeds

Forces

The properties in this group control the behavior of forces on this generator.

Align

In addition to influencing the frond’s shape, forces can also influence its original orientation. Each force has an Align strength in addition to its main strength. This strength causes the original orientation to be affected by the force.

Note

Only forces enabled on this generator will influence alignment.

Property	Description
Amount	The alignment strength of each enabled force is multiplied by this amount before being applied.

Forces

Each force in the scene has an entry here. Check the box next to the name to enable the force for this generator. The value set here is multiplied by the strength of the force before being applied to the branch. The profile curve controls how much force is applied along the branch.

Note

Click on the force name to edit the force's properties.

Material

The properties in this group control the material assignments and mesh resolution.

Frond

Applies a material to the frond mesh in this generator. Use the button controls to add [+] or remove [-] materials per geometry type.

Note

Fronds will use the mesh assigned to the material if it exists. If the material does not have an assigned mesh, a simple ribbon will be generated.

Property	Description
Material	Specify a named material from the Materials Asset Bar, or use a material set from the Material Sets Bar. Materials are chosen based on their weights and season settings.
Mesh	Use this property to choose a particular mesh from the material asset or allow it to pick randomly (Any), the first mesh on the asset (Primary), or any mesh but the first (Not primary).
Weight	Sets probability that a node will receive this material (this weight ÷ sum of all weights).
Flip	When enabled, randomly selected nodes are flipped over the y-axis.
Two sided	When enabled, the frond mesh geometry is duplicated for the reverse side. If you are looking to reverse the material and not the geometry, check the two-sided box in the Material Assets Bar instead.

Note

Keep in mind that on a two-sided mesh, the frond will have overlapping geometry if wind is enabled.

Mesh

Property	Description
Index	When set to a value other than zero, the mesh currently assigned will go up or down in mesh resolution ("High," "Medium," or "Low" detail on the mesh asset). Use this property (especially in conjunction with its parent curve) to adjust mesh resolution throughout the model. Note: Index requires meshes assigned in at least two of the three mesh asset LOD slots.
Resolution	This curve sets which mesh version ("High," "Medium" or "Low" detail on the mesh asset) is used based on the active resolution.

Shape

The properties in this group control how the mesh is manipulated when computing the frond.

Property	Description
Unification	This property lets you maximize the number of outward facing frond meshes. Parent spine rotations can often cause the frond mesh to face inward. With unification enabled, the initial orientation of frond meshes will be adjusted so that they face out relative to the selected anchor position. Choose from the following anchor positions: Global: The anchor point is located where the node's highest ancestor hits the ground. Deep: The anchor point is the base of a node very near (and sometimes exactly on) the root of the node's ancestors. Intermediate: The anchor point is somewhere in the middle of the node's ancestors. Local: The anchor point is very near where the node is attached. None: No anchor point is computed, and no unification is done. Origin: The anchor point is at the origin of the model.

Property

Description

Unification

This property lets you maximize the number of outward facing frond meshes. Parent spine rotations can often cause the frond mesh to face inward. With unification enabled, the initial orientation of frond meshes will be adjusted so that they face out relative to the selected anchor position. Choose from the following anchor positions:

Global: The anchor point is located where the node's highest ancestor hits the ground.
Deep: The anchor point is the base of a node very near (and sometimes exactly on) the root of the node's ancestors.
Intermediate: The anchor point is somewhere in the middle of the node's ancestors.
Local: The anchor point is very near where the node is attached.
None: No anchor point is computed, and no unification is done.
Origin: The anchor point is at the origin of the model.

Height

Displace the frond geometry based on the height map of the assigned material.

Property	Description
Amount	Increase or decrease the amount of displacement.
Offset	Shift the displacement.
Gravity	Pulls the edges of both sides of the frond mesh toward the ground. A negative value will pull the edges of the frond up towards the sky.
Fold	Folds each side of the frond toward each other (much like folding a piece of paper).
Curl	Curls both of the outside mesh edges in towards the spine.
Roll	Rotates the mesh around the parent spine.

Boundary

The properties in this group control where the frond starts and stops on its parent.

Property	Description
Start	Controls where the frond begins on the spine (0.0 corresponds to the beginning; 1.0 corresponds to the end).
End	Controls where the frond ends on the spine (0.0 corresponds to the beginning; 1.0 corresponds to the end).

Left-Right Variance

The properties in this group control how much the left and right sides of the frond differ in their deformation.

Property	Description
Amount	Adding this variance amount causes the two sides of a mesh to react independently to the amount of Curl, Fold, and Gravity.
Seed	Vary this value to change how the variance is computed.

Scale

The properties in this group scale the width and height of the mesh. The length is always controlled by the parent spine.

Property	Description
Width	Scales the width of the mesh. This scale corresponds to the x-axis of the mesh asset.
Height	Scales the height of the mesh. This scale corresponds to the z-axis of the mesh asset.

Section Variance

Add variance to the shape of individual sections of the mesh. Create sections by painting the mesh in the Cutout Editor. For more information, refer to Manipulate mesh sections.

Property	Description
Favor Outliers	When applying a range of variance, prefer extreme over median values to create more drastic variation.

Gravity

Pull the edges of both sides of the section toward the ground. A negative value pulls the edges towards the sky.

Property	Description
Amount	Add variance to the gravity applied to the mesh section.
Offset	Shift the applied variance by a set amount.

Fold

Fold each side of the section toward each other (much like folding a piece of paper).

Property	Description
Amount	Add variance to the fold applied to the mesh section.
Offset	Shift the applied variance by a set amount.

Curl

Curl both of the outside section edges in towards the spine.

Property	Description
Amount	Add variance to the curl applied to the mesh section.
Offset	Shift the applied variance by a set amount.

Roll

Rotate the section around the parent spine.

Property	Description
Amount	Add variance to the roll applied to the mesh section.
Offset	Shift the applied variance by a set amount.

Lighting

The properties in this group modify the vertex normals to change the lighting behavior of the frond.

Property	Description
Style	Choose an approach to edit the vertex normals for this generator. The Lighting group properties differ for each option. Global: Edit this generator as part of a larger group with global lighting properties. Local: Edit this generator individually with local lighting properties.

Lighting (local)

Property	Description
Alignment	This value causes the vertex normals to point in the direction of the parent spine's growth.
Spread	This value causes the vertex normals to point away from the parent spine.
Smooth	Use this property to compute smooth normals based on the average face normals at each vertex after the deformations have been computed. A value of 0.0 means no smoothing, a value of 1.0 means completely smoothed normals. The other lighting adjustments in this group are applied after smoothing.

Parent Puffiness

Property	Description
Anchor	This property picks a spot on one of the leaf's ancestors according to the following options: Global: The anchor point is located where the node's highest ancestor hits the ground. Deep: The anchor point is the base of a node very near (and sometimes exactly on) the root of the node's ancestors. Intermediate: The anchor point is somewhere in the middle of the node's ancestors. Local: The anchor point is very near where the node is attached. None: No anchor point is computed, and no parent puffiness is added. Origin: The anchor point is at the origin of the model. Surface X: The normals align with the x-axis of the parent where the node attaches. Surface Y: The normals align with the y-axis of the parent where the node attaches. Surface Z: The normals align with the z-axis of the parent where the node attaches.
Amount	Value scale that controls how much the normals on each individual leaf should face “out” depending on the assigned anchor point. A value of 1.0 makes each normal line up with the vector that goes from the anchor through the vertex.

Property

Description

Anchor

This property picks a spot on one of the leaf's ancestors according to the following options:

Global: The anchor point is located where the node's highest ancestor hits the ground.
Deep: The anchor point is the base of a node very near (and sometimes exactly on) the root of the node's ancestors.
Intermediate: The anchor point is somewhere in the middle of the node's ancestors.
Local: The anchor point is very near where the node is attached.
None: No anchor point is computed, and no parent puffiness is added.
Origin: The anchor point is at the origin of the model.
Surface X: The normals align with the x-axis of the parent where the node attaches.
Surface Y: The normals align with the y-axis of the parent where the node attaches.
Surface Z: The normals align with the z-axis of the parent where the node attaches.

Amount

Value scale that controls how much the normals on each individual leaf should face “out” depending on the assigned anchor point. A value of 1.0 makes each normal line up with the vector that goes from the anchor through the vertex.

Adjustments

Make final adjustments to the vertex normals.

Property	Description
Up	Rotate the vertex normals around the local x-axis.
Right	Rotate the vertex normals around the local y-axis.
Out	Rotate the vertex normals around the local z-axis.

Segments

The properties in this group control polygonal resolution when no mesh is assigned to the frond material.

Property	Description
Accuracy	Sets the number of segments in each rib of the frond infrastructure. Rib spines are computed for each side of the frond at each length segment of the parent spine. The final frond mesh is mapped to these ribs.

Note

Changing accuracy may drastically affect the shape of your spines. Set this value to the maximum desired fidelity early to avoid design losses. Higher values result in slower compute times.

Width

The properties in this group combine to set the number of width segments. Length segments are controlled by the parent spine.

Property	Description
Absolute	The minimum number of segments across the frond.
+ Relative	Segments are added to the Absolute value based on the length of the parent to arrive at the total number of segments across the frond.

Note

You must have vertices running up the center of your frond to avoid deformation artifacts (e.g., the frond separating from the spine). For fronds that don't use a mesh, favor even numbers of segments where possible.

Season

The properties in this group control how fronds transition in the seasons system, which affects their presence, shape and material changes. Frond transitions are determined by looking up season curves based on the position of the season slider.

Property	Description
Start offset	Determines when the frond starts to transition: 0.0 makes the transition start immediately, higher values delay the start, and negative values make it start sooner.
Time scale	Controls how long it takes for a frond to complete its transition. Higher values accelerate the transition. The default value of 1.0 means one year.
Drop time	Controls how long the frond remains attached. A frond can drop no matter what material is assigned.
Gravity	Makes the fronds droop as they transition, to give the impression of weight.
Curl	Makes the fronds curl as they transition.
Fold	Makes the fronds fold as they transition.

Tip

Use variance on these properties to slightly randomize the time and effects of the transition on neighboring fronds.

Post

The properties in this group influence how fronds in this generator participate in post-compute processing, such as leaf collision and shade pruning.

Property	Description
Take descendants	If a frond is eliminated during collision computations, checking this box will ensure that any of its children (and their children and so on) are also eliminated.

Collision

Define how the fronds in this generator participate in leaf collision.

Property	Description
Style	Set how the fronds behave during collision computations. Everything: Fronds in this generator collide with each other and all other leaves. Ignore siblings: Fronds in this generator ignore siblings but collide with everything else. Knock out others only: Fronds in this generator can’t be removed, but they can eliminate leaves in other generators. Nothing: These fronds don’t participate in collision computations.
Weight	When fronds collide, the one with the higher weight wins. Use this property to set the weight.
Pivot threshold	Sets how far away from pivot (as a percentage of size) a collision has to happen in order to count. Use this property to eliminate unwanted removals of fronds anchored near each other.

See also the shared Post properties which apply to this feature.

Shade Pruning

Define how the fronds in this generator behave when you enable Shade Pruning.

Property	Description
Style	Select the layer of the tree to start pruning from. None: No fronds in this generator participate in shade pruning computations. Interior: The pruning starts from the most shaded fronds at the interior of the tree. Exterior: The pruning starts from the least shaded fronds at the exterior of the tree.
Threshold	Set the relative shade level up to which the Modeler removes fronds during pruning.

Wind

The properties in this group influence how fronds are animated in wind simulations. There are separate settings for VFX, Games, Legacy UE4/Unity, and Lumberyard.

Property	Description
Weight	Use this property to scale how much the nodes move during wind simulations. The amount and frequency of motion are set on the Fan object. The left-hand side of the profile curve corresponds to the pivot point. The right-hand side corresponds to the vertex farthest away. Note: The left-hand side of the profile curve must be zero to avoid disconnecting from the parent.
Cross	Influences the amount of motion as the frond grows from the parent spine to the edge.
Boost	Adds extra weight to the wind as an absolute value. The left side of the curve corresponds to the base of the frond and the right side corresponds to the tip.

Ribs

Fronds are constructed along “ribs” growing perpendicular to the parent branch. These properties control the motion of those ribs.

Property	Description
Apply branch wind	Adds wind to the ribs at one level higher than that of the parent branch. For more information about wind levels, see VFX wind.
Weight	Control how much wind is added to the ribs.

Growth

The properties in this group control how the model behaves during animated growth. In general, you create the model in the fully grown state and use these properties to control how it gets there.

Property	Description
Speed scale	The speed at which a frond will grow is set on the Timeline Bar. Use this property to scale that value. The profile curve scales the speed relative to the fronds' total growth time. For example, ease in and out of the growth animation by using an s-curve.

Transitions

Property	Description
Gravity	Adds additional gravity to the frond at the start of the growth. The profile curve sets how much of the additional gravity is added during the growth cycle of the frond.
Curl	Adds additional curl to the frond at the start of the growth. The profile curve sets how much of the additional curl is added during the growth cycle of the frond.
Fold	Adds additional fold to the frond at the start of the growth. The profile curve sets how much of the additional fold is added during the growth cycle of the frond.
Roll	Adds additional roll to the frond at the start of the growth. The profile curve sets how much of the additional roll is added during the growth cycle of the frond.

Dynamic LOD

The properties in this group control the LOD behavior of the fronds.

Property	Description
Weight	Increases or decreases the likelihood that fronds in this generator will survive the LOD process (vs. fronds in other generators). Use the parent curve to target specific areas of the model.
Mesh	Controls which mesh LOD (if present) is used for each LOD state. The left side of the curve corresponds to the highest LOD. The right side corresponds to the lowest LOD.

Note

Mesh requires meshes assigned in at least two of the three mesh asset LOD slots.

Vertex Color

The properties in this group control how vertex colors are computed.

Note

Vertex colors must be enabled on the Tree generator for these properties to work.

Red

The properties in this group control how the red component of the color is computed.

Property	Description
Style	This property controls how the red portion of the color is computed from the following options: Set: Sets the color directly using the Value property (parent colors are ignored). Offset from parent: The Value property is added to the vertex color inherited from the parent.
Value	This property adds to, subtracts from, or directly sets this color component.
Cross	Multiply the vertex color along the length of the rib. For example, use the Linear growth curve to make colors brighter at the tips.

Green

The properties in this group control how the green component of the color is computed.

Property	Description
Style	This property controls how the green portion of the color is computed from the following options: Set: Sets the color directly using the Value property (parent colors are ignored). Offset from parent: The Value property is added to the vertex color inherited from the parent.
Value	This property adds to, subtracts from, or directly sets this color component.
Cross	Multiply the vertex color along the length of the rib. For example, use the Linear growth curve to make colors brighter at the tips.

Blue

The properties in this group control how the blue component of the color is computed.

Property	Description
Style	This property controls how the blue portion of the color is computed from the following options: Set: Sets the color directly using the Value property (parent colors are ignored). Offset from parent: The Value property is added to the vertex color inherited from the parent.
Value	This property adds to, subtracts from, or directly sets this color component.
Cross	Multiply the vertex color along the length of the rib. For example, use the Linear growth curve to make colors brighter at the tips.

Mesh Asset

The properties in this group control how vertex colors stored in the mesh asset are combined with the computed vertex colors.

Property	Description
Style	This property controls how mesh asset vertex colors are used from the following options: Interpolate: The Contribution value is used to blend from the computed to color (0.0) to the color stored in the asset (1.0). Add: The Contribution value is used to scale the mesh asset vertex color and the result is added to the computed vertex color.
Contribution	This value sets how much influence the mesh asset vertex color has on the final vertex color.

Lightmap

Lightmap UVs are computed for several versions of the Modeler designed for use with game engines. Lightmap UVs are a UV set where no objects overlap and all of them fit in a single space where U and V fit in the range [0.0, 1.0].

Property	Description
Weight	Influences how much space in the lightmap fronds made by this generator can have. Every object's lightmap weight is compared to every other object and then the lightmap packing is determined. This means that your weight value may not be honored exactly or may get so large as to exhibit unexpected results. Use Tools > Reset lightmap scalars to go back to default values for the whole model.

Property

Description

Weight

Influences how much space in the lightmap fronds made by this generator can have.

Every object's lightmap weight is compared to every other object and then the lightmap packing is determined. This means that your weight value may not be honored exactly or may get so large as to exhibit unexpected results. Use Tools > Reset lightmap scalars to go back to default values for the whole model.