Branch generator properties

The Branch generator creates 3D branch geometry. It’s used for trunks, boughs, branches, twigs, roots, etc. The following sections detail each of the Branch generator's properties.

Generation

Refer to Generation properties.

Forces

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

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.

Allow

When enabled, all forces that are checked will act on the generator.

Align

In addition to influencing the branch'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.

Style

Choose the style of the alignment operations:

Property	Description
None	No alignment will take place.
Individual	Each node is aligned without regard for the behavior of any of its siblings.
Group	A single alignment is computed for all siblings.

Amount

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

Random Seeds

Refer to Random seeds properties.

Segments

Accuracy

Sets the exact number of points in the high-resolution spine that is computed as the frame of the branch.

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 computes.

Influence

Scales how much influence forces and other spine properties have per accurate spine segment. If you change the number of accurate segments at any point, try adjusting this number to get the generator to more closely match its previous look.

Scalar

Increase or decrease the number of polygons on the mesh.

Length

Sets the number of segments used along the length of the branch. The final number of segments is the sum of the Absolute and + Relative values.

Style

Choose how length segment distributions are computed.

Property	Description
Default	Segment locations are computed very accurately.
Legacy	Segment locations are computed in the manner of version 8 for backward compatibility.

Absolute

Sets the minimum number of length segments used. Each branch will have at least this many segments, regardless of length (use this sparingly or for specific uses like the trunk).

+ Relative

The number of segments is computed based on the branch length and this value. This number is added to the Absolute segments for the final number of length segments used.

Relative basis

Choose how relative length segments compute.

Property	Description
Length only	The length of the branch alone is the basis for how many segments are added for the + Relative amount.
Length/radius ratio	Relative segments are added based on the ratio of the length of the branch and its starting radius. This style keeps similar numbers across a wide variety of branches and should be preferred.
Parent’s length segments	The length of the parent is the basis for how many segments are added for the + Relative amount.

Weld scalar

Adjusts the number of segments composing the fused part of welded branches.

Optimization

Adaptively removes segments based on the curvature of the branch. Increasing this value increases the angle that must be met for a length segment to survive the optimization.

Radial

Sets the number of segments composing the radial cross-section of branches. The final number of segments is the sum of the Absolute and + Relative values.

Absolute

Sets the minimum number of radial segments used. Each branch will have at least this many segments, regardless of the radius (use this sparingly or for specific uses like the trunk).

+ Relative

The number of segments is computed based on the branch radius and this value. This number is added to the Absolute segments for the final number of radial segments used.

Relative basis

Choose how + Relative radial segments compute.

Property	Description
Radius	The radius of the branch is the basis for how many segments are added for the + Relative amount.
Parent’s radial segments	The radius of the parent is the basis for how many segments are added for the + Relative amount.

Features

Feature vertices are either taken from meshes assigned to branch materials or are painted on manually in freehand mode. Both methods allow you to place vertices on and around important features of the branch. Feature vertices from the material will follow features everywhere they are mapped. Hand-painted feature vertices will only be where they are placed.

Note

The addition of any feature vertices or any change in their number or placement will force the branch to retriangulate.

Mesh

These properties control whether and from which LODs the feature vertices are taken. To add feature vertices to a material asset, add one or more cutout meshes to a branch material. A copy of these vertices will be added to the branch to match each tile in UV space.

Enabled

Adds feature vertices to the branch from the material's meshes.

Keep chance

This property represents the probability that a feature mesh will be used each time a valid place to put it is encountered (1.0 = always use it, 0.0 = never use it). Use this property in conjunction with its parent curve to eliminate feature vertices in unwanted places.

Vertex %

Controls how many of each feature mesh's vertices are used. Use this property in conjunction with its parent curve to thin out feature vertices in areas where they have little impact to save on vertex and polygon counts.

LOD offset

Specifies which LOD mesh should be used when retrieving feature vertices.

Stitching

The properties in this group pad areas around small feature vertex clusters to preserve branch shape, especially on low polygon count models.

Style

Choose how vertices are added in from the following options:

Property	Description
No new segments	No new vertices are added. This style is most appropriate on high-polygon VFX models.
Preserve cross section	Vertices are added to fill out the areas around feature vertex clusters. Use this style to make sure that branches maintain their roughly cylindrical shape even when feature vertices are used on low-polygon branches. Vertices close to nearby vertices are not added in order to minimize polygon counts.

Scale U

The automatically computed number of padding vertices across the branch is multiplied by this number. Values less than 1.0 reduce the polygon count at the expense of potential shape irregularity.

Scale V

The automatically computed number of padding vertices along the branch is multiplied by this number. Values less than 1.0 reduce the polygon count at the expense of potential shape irregularity.

Freehand

The properties in this section control the creation of new vertices based on freehand vertex painting.

Density

Increase this value to add more vertices in painted areas. Decrease it to lower the vertex count.

Seed

Change this value to change how the painted vertices are distributed.

Resolution

The properties in this group scale the number of segments based on the selected resolution (High, Medium, Low, or Draft).

Note

Resolution curves are applicable only to the VFX line of SpeedTree products.

Length

Scales the number of length segments for each resolution.

Radial

Scales the number of radial segments for each resolution.

Features

Scales the number of feature vertices for each resolution.

Spine

The properties in this group control the shape of the branch.

Length

These properties set the length of the branch.

Absolute

Sets the minimum length of the branch.

+ % of parent

A length equal to this value multiplied by the length of the parent is added to the Absolute value above to set the length of the branch.

+ % of radius

A length equal to this value multiplied by the radius of this branch is added to the Absolute and + % of parent values above to set the length of the branch.

Note

Favor + % of parent and + % of radius wherever possible. Doing so makes randomization more effective and allows for easier reuse of generators within and between models.

Match one V tile

Sets the length to exactly match the length of one V tile based on the material's aspect ratio and the branch's radius. Hint: Use this when you need the material to exactly line up with the end of the branch, for example, when using an extension as a bridge to blend from a base trunk map to a new map for the tip of the trunk.

Stop shape control

When enabled and Shape Control is being used, this property stops Shape Control from being computed on this generator (and its descendants, unless a new shape is started).

Shape scale

Scales the length of spines under shape control. The length value computed by the shape algorithm is multiplied by this value before it’s used.

Clamp

Min

Set the minimum length of branches.

Max

Set the maximum length of branches.

Orientation

The properties in this group control the initial orientation of the branch.

Start angle

The amount of angle offset from the parent node's growth direction at the point where each node occurs, where 0.0 is equal to the parent's direction, 1.0 is opposite the parent's direction, and 0.5 is perpendicular to the parent.

Start roll

Use this property to rotate the direction the Start angle is applied. A value of 0.0 means that the start angle is applied along the parent branch. Negative values rotate the branch clockwise. Positive values rotate the branch counterclockwise.

Alignment

Computes an interpolation between a random up direction and absolute (world) up. This property rotates the branch in an attempt to make the "top" of each branch point up as much as possible. Use this to make fronds parallel to the ground.

Roll

Uniformly rotates each branch. This property computes after Alignment.

Unify

Forces branch nodes on opposite sides of their parent to be oriented in the same direction. Rotation adjustments like Roll and Frond Roll keep opposite nodes synchronized when this option is enabled. This option is especially useful when modeling long, narrow fronds on a stem (e.g., ferns).

Weld start

Enable this option when using "Spine only" branches to make the branch start on the surface of the parent's skin rather than on its spine. This option is useful for making sure fronds touch, but don’t cut into, the parent stem.

Shape

The properties in this group (along with Forces) control the shape of the branch as it grows.

Gravity

Positive values pull branches down, negative values push branches up (in world space). Gravity is equivalent to a downward pointing direction force.

Ancestor

Positive values cause the branch to grow in the direction of its parent. Negative values push it away. For example, if Ancestor is set to a positive value, then all the branches created by this generator will grow towards the direction of the parent spine, like a bud. If set to a negative value, then all the spines will grow away from the spine, basically unraveling.

Straightness

Sets the amount of straightness or noise removal applied to the branch after Noise has been computed. However, this property is applied full force at the base of the branch and gradually reduces the force towards the tip of the spine to none.

Twist

Twists the branch along its central axis. The curls are applied in the order they appear on the Property Bar.

Parent Curl

The properties in this group add curl to the branch.

Up

Curls around the parent branch.

Right

Curls around the axis orthogonal to the parent branch's direction and the initial direction of the branch.

Out

Curls around the axis straight out from the parent branch.

Zigzag

The properties in this group give the branch a zigzag pattern.

Intensity

Increasing this property increases the angle in each zig and zag.

Segment Length: Absolute

Sets the minimum number of zigzags. Use the profile curve to scale the length of each zigzag along the branch.

Segment Length: + Relative

Adds extra zigzags based on the length of the branch.

Prune

The properties in this group remove branches based on their orientation.

Interior

Removes branches that grow toward the interior of the model.

Up

Removes branches that point up.

Down

Removes branches that point down.

General

Removes branches at random.

Ground

Removes any branch that intersects the ground plane.

Path

The properties in this group allow you to trace out a deformation path for the spine.

Amount

Controls the amount and shape of the deformation. The value sets the amount and the profile curve sets the shape.

Twist

Twists the deformation along the spine as it is applied.

Length

The length over which exactly one tile of the deformation shape is applied. If this length is shorter than the branch, the deformation will tile.

Offset

Shifts where the deformation is applied. You can use variance on this property to apply the same deformation shape to many branches without an obvious repeating pattern.

Noise

Sets the amount of randomness applied to each angle along the spine length. Noise adds bends and deformation to the branch spine. The difference in Early and Late noise is based on when the noise is factored in the computation.

Early

Early noise is computed while the spine is being shaped. It is important to note that with early noise, randomization may result in wildly different shapes. Early noise causes more chaotic shapes than Late noise.

Amount

Controls the intensity/strength of noise applied to the spine.

Turbulence

Controls how chaotic the wave that creates the noise is on the spine.

Threshold

Controls the point on the spine that needs to be exceeded for the noise to come into effect.

Note

Altering the profile curves affects where the noise starts and ends.

Late

Late noise is computed after the spine is shaped.

Amount

Controls the intensity/strength of noise applied to the spine.

Turbulence

Controls how chaotic the wave that creates the noise is on the spine.

Smooth

Straightens the noise that was applied to the spine. Setting the value to 1.0 will completely straighten the branch spine.

Note

Late noise is the best way to add an organic look to your model while keeping it under control.

Seed

This seed is used to control the noise pattern. Change this value to change the noise without randomizing any other part of the model.

Jink

The properties in this section straighten out sections of the branch to simulate a branch's tendencies to grow in linear segments in many species. Use these properties to straighten out turbulent noise while maintaining the basic shape.

Amount

Controls how much the branch moves toward the shape computed by the jink algorithm. A value of 0 keeps the branch as it was. A value of 1 makes the branch composed entirely of long, straight segments.

Absolute

Sets the minimum number of straight segments.

+ Relative

Adds additional straight segments based on the branch's length.

Uniformity

Controls how similar in length each straight segment is.

Seed

Change this value to randomize only the jink calculations while keeping the rest of the branch the same.

Note

Changing the seed has no effect when Uniformity is set to 1.0.

Break

The properties in this group control if, where, and how often branches will break.

Chance

Sets the likelihood that any node will break, resulting in an open branch at the break spot. Cap generators can be added as children to close off the break.

Spot

The percentage of the way along any spine where the branch will break.

Seed

Change this value to recompute where breaks happen.

Shape Control

The properties in this group implement the Shape Control technique.

Style

Determines the method used for controlling the shape of this generator's descendants.

Property	Description
None	Choosing none will keep the Shape control properties grayed out. No changes will occur to the model.
Sphere	Branches are constrained to a circular shape.
Enabled geometry forces	Branches are constrained to the shape of any active geometry forces on the model.

Position

Determines placement of the spheres along the spine. A value of 0.0 is at the base of the spine, and a value of 1.0 is at the tip of the spine. Going over the value of 1.0 pushes the sphere placement off the spine.

Distribution style

Selects what type of generators influence the length of branches under shape control.

Property	Description
Branches only	Only branch generators factor into the shape control algorithm.
All descendants	Every generator that is a descendant of the generator initiating shape control influences the length of branches under shape control.

Distribution

Distribution lets you push and pull the relative lengths from one end of the sphere to the other. For example, sliding distribution to the right will create longer lengths in the first set of branches and shorter ones in the last set.

Size

Absolute

The exact size of the spheres used for shape control.

+ % of size

Using the amount set, this property re-computes the size of the spheres based on the length of the spine, so a spine that is longer will have a larger sphere.

Note

You can see how these properties affect the model by enabling Show > Hints in the Tree Window toolbar.

Skin

The properties in this group control how the mesh around the spine is generated.

Type

Sets the style of the skin.

Property	Description
Polygons	The branch is composed of triangles or quads. No hole is cut into the parent.
SubD surface (rectangular attachments)	A rectangular hole is cut into the parent and the branch is treated as part of a subdivision surface cage.
SubD surface (arbitrary attachments)	Arbitrarily cuts out a hole in the parent, taking only the quads it needs, and the branch is treated as part of a subdivision surface cage.
Spine only	No mesh is applied to the spine. Use this option to provide the stems for fronds.

Visibility

Branches with Visibility values greater than 0.5 have geometry. Those with less than 0.5 do not. Use this property to judiciously hide branches to save on polygonal complexity.

Radius

These properties control the radius of the extruded branch skin.

Absolute

Sets the minimum value of the radius.

+ % of parent

Radial size is determined based on a percentage of the parent's radial size at the point where the branch is attached. This value is added to the Absolute radius.

Clamp to parent

When enabled, the child radius cannot exceed the radius of the parent.

Length compensation

Occasionally, branches thin out to a point at the tip of the spine too fast. This feature allows you to compensate by making the radius at the tip of the spine larger.

Length kill ratio

Removes any branches where the length of the branch divided by its radius exceeds this value. Use this to automatically eliminate very thin branches. A value of 0.0 will disable this feature.

Clamp

Min

Set the minimum radius of branches.

Max

Set the maximum radius of branches.

Light seam reduction

Sets the amount to bend the normals toward the spine's direction.

Note

Normal bending increases exponentially near the base of the branch since light seams occur where branches intersect.

Roll

Rotates the skin of the branch around the center spine without changing the underlying shape.

Smooth

Push out vertices around curves and bends to smooth the area.

Welding

Controls the junction between branches and their parents.

Enabled

When checked, branches will be pushed out and fused to their parent, creating a seamless union between the two.

Keep

Sets where to keep welds on the model.

Hint: Use the curve relative to the Trunk generator to keep welds at the top or bottom of the model.

Keep failed

When checked, branches that failed to weld are still computed. Use this to help find and correct failed welds in critical regions (failed welds in fine detail areas are often okay).

Force ray casts

When checked, welding uses ray casts to attach to the parent rather than internal procedural data. This often results in more failed welds but can produce better results when welding to heavily deformed parents (e.g., squashed and deformed branches).

Offset

Controls how far out the branch is pushed off the surface before welding back to the parent. It's essentially the length of the weld region.

Spread

Controls how much the branch spreads out from its natural radius near the weld site.

Amount

Sets the base amount of the spread.

Upper scale

Sets the amount to spread the top weld segments of the child branch on the parent branch, creating a web where the branches meet.

Lower scale

Sets the amount to spread the bottom weld segments of the child branch on the parent branch, creating a web where the branches meet.

Blend

Sets the method used for applying intersection blending.

Texture

Sets the amount to extend or pull the blended texture region up the child branch, elongating or squashing the texture mapping.

Texture scale

Resizes the texture map in the blended region.

Contrast

Controls the contrast or harshness of the blended textures on the weld (between the parent and child).

Noise

Sets the amount of the noise (wave frequency) to encircle the branch radius between the two blended textures so there is not a uniform blend line.

Lighting

Alters the Normal alignment of the branch skin in the weld region.

Note

A curve set to Min means that the normals are rotated to follow the direction of the spine. A curve set to Max means all the normals are rotated to point out based on its position on the spine.

Subdivision

These properties control the junction with the parent for branches whose Skin > Type is set to either of the SubD surface options.

Relax scale

Averages out the vertices at the junction in order to remove artifacts.

Smooth

Controls how far away the child's ring is from the parent. The closer the child's ring is to the parent, the harsher the intersection is. The further out the child's ring is, the smoother the intersection is.

Texture density

Determines the denseness of the texture applied around the intersections.

Upper spread

Extends the upper junction point higher on the parent. Junctions will always occur at the closest ring on the parent to this setting.

Lower spread

Extends the lower junction point lower on the parent. Junctions will always occur at the closest ring on the parent to this setting.

Squash

These properties are used to make the branch cross-section more elliptical rather than circular.

Amount

Reduces the scale of one side of the branch radius in order to get a flatter shape.

Rotate

Rotates where the flattened area is located on the branch.

Splits

It is possible to split the trunk into two open ends ready for extension branches. These properties control the likelihood and nature of branch splits.

Chance

Sets the likelihood that the extended parent will split, or divide, into two branches. A value of 0.0 means there will be no chance of splitting, a value of 1.0 means it will split if it can.

Note

There must be at least two U texture tiles in order for a split to happen.

Balance

Controls the balance of the radius size between the two split branches. At 0.5, both spines will be the same radius.

Seed

Controls the random values used to create the splits.

Spread

These properties control how much the children of this branch spread out after the split.

Side 1

Controls the angle of one side of the split branches away from the center of the tree.

Side 2

Controls the angle of one side of the split branches away from the center of the tree.

Expand

Controls how much the cross-section of each split side expands from its default state.

Side 1

Controls the expansion of one side of the split.

Side 2

Controls the expansion of the other side of the split.

Smooth

Controls the shaping of the split region.

Inner

Controls the smoothness of the inner crease between the split spines. A value of 0.0 means no smoothness and a value of 1.0 gets rid of the crease.

Outer

Controls the smoothness of the outer bend of the parent spine and child spines where the split occurs.

Extensions

The properties in this group modify the traits of extensions created by this generator. These properties are useful for adjusting extensions when the fact that they're at the end of a branch causes them to stand out. These properties are preferred over using a parent curve with a harsh change near the end on standard properties.

Spine

These properties affect the spine of extensions.

Length scale

Scales the length of extension spines.

Spread

When more than one extension exists on a branch, this value controls how much they separate. Use the profile curve to control how much of the spread is applied along the length of the extensions.

Skin

These properties affect the skin of extensions.

Radius

Use the profile curve to control the radius along the length of the extension. The value controls how much the profile curve is used. These adjustments are all made relative to what the branch would compute were it just near the end of the branch but not an extension.

Normal smooth

This value smooths out the normals when there is more than one extension on a branch. Use this property to help hide the seam between extensions.

Displacement scale

Scales the displacement values used on the extensions.

UV Mapping

The properties in this group control the UV coordinate generation.

Style

Sets the method by which UVs are computed.

Property	Description
Unrestricted	No locks. Unlimited tiling for both U and V.
U locked [0,1], V unrestricted	Forces all U coordinates to be in the range [0.0, 1.0], but allows unlimited V tiling.
U and V locked [0,1]	Locks both U and V texture maps to the range [0.0, 1.0].

Extension style

Set the style by which UV coordinates are generated for any nodes that are extensions in this generator.

Property	Description
Automatic	All extensions will continue the UV mapping from their parent.
Manual (match)	UV offsets will be relative to those that would match their parent.
Manual (match u only)	U will match exactly, V is free to edit.
Manual (full control)	Full control of UV coordinates will be allowed.

U

U coordinates circle the branch.

Absolute

Sets the minimum number of times the material tiles around the branch.

+ Relative

The number of additional tiles based on the branch radius and this number are added to the Absolute value above to set the final number of times the material wraps in U. This value is always at least 1 and is always an integer.

Offset

U values are shifted by this amount.

Note

Use variance on this property to make branches each have a random orientation to the U wrapping.

Fractional

U tiling values are forced to the nearest integer value during normal texture coordinate computation to facilitate seamless tiling; however, this is not always desirable. For instance, if you need to target a branch component in a custom atlas you'll need to use fractional values in combination with U offset to focus on a section of the atlas.

Enable

Toggles whether or not fractional U values are allowed. If they are, only the Value property in this group affects the U coordinate.

Auto

Enabling this property means the value will be set automatically to a number that will result in the closest possible match to the texel density of the parent. There will be a seam in the texture but it may not be noticeable from the viewpoint of the intended scene.

Value

This property directly sets the U tiling value and is not restricted to integers. Absolute and + relative are ignored.

Twist

Controls how much the UV mapping twists around the branch.

Amount

Sets the number of full revolutions to twist the material per V tile.

Random flip

Randomly flips the texture twist direction.

V

V coordinates run along the branch.

Style

This property selects the method used to compute V coordinates.

Property	Description
Absolute	V tiling is set explicitly.
Relative (keep aspect ratio)	V tiling is computed based on the U tiling and branch radius in such a way that the aspect ratio of the applied material is maintained.
Relative	V tiling is computed based on the length of the branch.

Anchor

This property selects which end of the branch the V coordinates are computed from.

Property	Description
Start	V coordinates are computed from the start towards the end.
End	V coordinates are computed from the end towards the start.

Scale

Controls the amount of V tiling.

Skew correction

When the style is set to Relative (keep aspect ratio), this property controls how much of an attempt is made to fit the mapping to the changing radius of the branch. A value of 0.0 makes no correction. A value of 1.0 adjusts the V coordinates to accommodate branches that get narrower or wider. Use this property to avoid the appearance of stretched maps, especially as branches narrow near the end.

Pinch

Fine-tune V texture coordinates near the end of a branch when repeating or clamping artifacts are visible.

Offset

V values are shifted by this amount.

Note

Use variance on this property to make branches each have a random start point for the V coordinates.

Tiling

The properties in this group control how tiling UV coordinates are handled.

Style

Controls what happens when UV coordinates will be computed that are outside the range [0.0, 1.0].

Property	Description
Tiling	UV coordinates are permitted to go outside the range [0.0, 1.0] and will rely on texture tiling to appear correctly.
0-1 patches (choose one assigned material)	The branch will be computed in patches where all UV coordinates are in the range [0.0, 1.0]. One material will be chosen based on assigned materials and their weights and will be used on all patches.
0-1 patches (use all assigned materials)	The branch will be computed in patches where all UV coordinates are in the range [0.0, 1.0]. The assigned materials will be used to create a patchwork based on their weights and location assignments. Use this style to mix a unique base (choose First placement) with tiling bark sections.

Note

The patch options will result in a doubling of the vertices along the seams to implement unique [0.0, 1.0] sections.

Optimize segments

When enabled, length and radial segments are chosen to minimize the occurrence of segments placed very near each other. Use this option to eliminate rings very near to each other near the patch transitions.

V tolerance

Length segments that fall on whole number V texture coordinates are favored over those that are near it. Adjust this value to control how close to whole number V segments any segment can be. Use this property to clean up areas around patch edges.

Seed

Randomizes the distribution of materials on the patches when the style is set to 0-1 patches (use all assigned materials).

Materials

The properties in this group control the material assignments.

Branch

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

Material

Specify a named material from the Materials Bar, a named set from the Material Sets Bar, or use Inherited to pick up the material from the parent.

Weight

Sets the probability that a node will receive this material index (this weight ÷ the sum of all weights).

Patch options

Choose how to apply the material. See UV tiling. This property is visible only when UV Mapping:Tiling:Style is not set to Tiling.

Property	Description
UV Area	Choose to apply the full UV map or a UV area.
	Whole map	Apply the full UV map.
	Any	Apply any UV area. This option is visible only if the material has multiple UV areas.
	Custom area name	Apply a specific UV area. Set and name the area with the UV Area Editor.
Placement	Place the material anywhere or on the first ring.

Note

Using multiple branch maps will require additional draw calls in real-time use.

Extensions

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

Note

Empty material slots default to Inherited. This setting is typically fine for extensions.

Material

Specify a named material from the Materials Bar, a named set from the Material Sets Bar, or use Inherited to pick up the material from the parent.

Weight

Sets the probability that a node will receive this material index (this weight ÷ the sum of all weights).

Displacement

The properties in this group move the vertices of the branch mesh to simulate a rough surface.

Note

The more vertices you have in the branch, the better displacement will look.

Radial amount

Sets the maximum amount any of the vertices will move away from (positive values) or toward (negative values) the spine.

Length amount

Sets the amount the vertices will move in the direction of the spine. Values other than 0.0 will result in vertices that share V texture coordinates no longer lying in the same plane.

Sharpness

Sets the displacement amount for any given displacement value. For example, for a given vertex, let's say the algorithm decides it needs to be displaced by 0.25 of the maximum value. Before that 0.25 is applied, it is used to look up a new value from this curve. So, a linear growth curve will leave the value unmodified; however, other curve shapes will allow you to have different regions of displacement to have more or less effect on the model. An exponential growth curve will cause sharp displacement because only high values have a significant effect.

Source

Selects the source of data for the displacement.

Property	Description
Noise	Uses noise for displacement.
Material	Uses the map in the height channel of the assigned material for displacement.
Displacement	Uses a named displacement asset as the displacement source.

Mapping

Property	Description
Use UVs	Follows the geometry’s UV coordinates to map the displacement.
Fit to geometry	Applies displacement once around and along the branch.

U scale

Scales the noise pattern around the model.

V scale

Scales the noise pattern along the model.

Seed

When using Noise as the source, change this property to vary the pattern.

Fine

Fine displacement is a second displacement pattern that is always noise based.

Amount

Sets the maximum amount any of the vertices will move. Vertices always move out or in along the surface normal. This movement will be on top of any other displacement.

Sharpness

This curve sets the displacement amount for any given displacement value. For example, for a given vertex, let's say the algorithm decides it needs to be displaced by 0.25 of the maximum value. Before that 0.25 is applied, it is used to look up a new value from this curve. So, a linear growth curve will leave the value unmodified; however, other curve shapes will allow you to have different regions of displacement to have more or less effect on the model. An exponential growth curve will cause sharp displacement because only high values have a significant effect.

Scale

Sets the size of the noise. Values greater than 1 will push the displacement outwards and less than 1 will bring the displacement in towards the center of the branch.

Shape

Adds length creases, following the direction of the spine, to break up the branch radius. This property is useful for adding detail into the branch without having to import a displacement map.

Amount

Sets the strength of displacement that creates the creases.

Twist

Sets the amount of rotation of the spine that is applied to the shape displacement. The rotation begins from the base.

Scale

Scales the noise pattern.

Seed

Varies the shape noise.

Flares

Flares are a special type of displacement designed to simulate the bottom of a trunk as it expands into the underground root system.

Radius

Sets the maximum amount of any flare displacement (expressed as a multiple of the branch radius).

Noise scale

Flares are computed based on a noise pattern. Use this value to scale the pattern.

Height

Sets the distance the flare extends up the spine of each branch.

Pinch

Sets the amount the flares should be pulled in towards the center spine. A value of 1.0 means that there is no spread in the base of the flares.

Angle

Rotates the flares of the branch around the center spine.

Seed

Varies the flare noise pattern.

Dynamic LOD

The Dynamic LOD System automatically creates multiple levels of detail for a model. The purpose is to allow the model to degrade in detail in real-time applications. This should not be confused with Resolution, which is designed to set the polygonal resolution of a model exported for VFX use.

Weight

Influences how likely nodes in this generator will be kept during LOD computations. The generator with the higher value will have priority over the other generators of the same type.

Optimization

Increases the length segment optimization property for each successive LOD state. Use this to dynamically reduce length segments based on curvature.

Length segments

Scales back the number of length segments for each successive LOD.

Radial segments

Scales back the number of radial segments for each successive LOD.

Features

Scales back the number of feature segments for each successive LOD.

Wind

The properties in this group control the wind behavior of the branch. There are separate settings for VFX, Games, Legacy UE4/Unity, and Lumberyard.

Apply

Applies wind at this level. This property can be ignored if the available wind levels are already taken. When wind is enabled, the generator icon in the Generation Editor will show the wind level ultimately assigned to this generator based on the hierarchy.

Weight

Controls how the wind weight is computed for this branch.

Inherited weight scale

Use this property to exaggerate the weight of anatomical calculations.

Level offset

In multi-level wind algorithms, this value will cause the assigned wind level to increase by this amount. This feature is useful in situations like assigning twigs to trunks. This happens frequently in nature, and you'll want to make sure the twigs animate like other twigs farther down the hierarchy.

Style

Choose the method by which weight is computed.

Property	Description
Absolute	Weight is computed without regard for any of the branches that came before it.
Anatomical	Weight is computed based on the anatomy of the model.

Value

The strength of the wind effect on this set of nodes. This value is a multiplier of the motion values set for the corresponding level on the Fan.

Note

The left-hand side of the profile curve must be zero to avoid branch disconnections.

Amount

This property sets the amount per unit length of weight applied to the branch. This value is added to the weight value where each branch is connected to its parent.

Season

The properties in this group provide the mechanism by which assigned materials can change with the Seasons slider.

Note

Although season changes on branches aren't usually that noticeable, you can use this mechanism to switch to burnt barks, barks with or without lichen, or any other variation you'd like to be housed in the same model.

Start offset

Determines when the branch will start to transition. The default value of 0.0 means it will start immediately (higher values delay the start, lower values make it start sooner).

Time scale

Controls how long it will take to complete its transition. The default value of 1.0 means one year.

Descendant offset

Applies an offset, based on the value entered, to the spines. So if a value of 0.2 is set, then the nodes along with their children will be offset by that amount. Hint: Use this to get some of the branches earlier or further along the season transition. This way there is some variance in the timing of the season transition.

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.

Speed scale

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

Radius style

Choose how the radius is treated.

Property	Description
Reveal profile	Gradually reveal more of the profile as the branch grows.
Stretch profile	Apply the full radius profile curve to whatever portion of the branch has been revealed.

Radius

Scales the speed at which the radius of the branch increases. For example, a linear growth curve will cause the radius to grow linearly from the beginning to the end of the branch's growth cycle.

Smoothing

Branches can be oriented either based on the current state of their parent (0.0 smoothing), the final state of their parent (1.0 smoothing), or anywhere in between. Increase this value to prevent wild branch motion during growth. This is especially useful for branches growing off of a twisted or gnarled parent.

Unfurl

This property causes the Start angle to animate from being in line with the parent to its final orientation during the growth animation. Use this property to make branches (and fronds growing off of them) appear to open up as the animation proceeds.

Allow extension control

Enable this property to apply growth timing to extensions as well as regular branches. With the box unchecked, extensions grow exactly in time with their parent.

Timing

Style

Sets the conditions under which the branch will start growing. The Start % property works according to the option selected here.

Property	Description
In place	The branch will start growing exactly when the parent is long enough to reach its starting point in the fully grown model. Start % has no effect. This style makes the animation appear to trace out the model as in the vines growing over rocks, for example.
Parent	The growth of this branch will be based on the growth of the parent. A Start % of 0.0 means start when the parent starts, 1.0 means start when the parent ends.
Parent's start and end	The growth of this branch will start and stop in synchronization with its parent. Start % has no effect. This option is good for features like roots.

Start %

Causes branches to start early (0.0) or late (1.0) according to the Style property.

Offset

The start frame is shifted by a constant number of frames (negative means earlier, positive means later). This value is best used to “jumble up” the start times of neighboring branches.

Note

It is almost never a good idea to go negative with this value (branches can't grow earlier than the structure will allow). A good practice is to have a value of something like 10 and a variance of 10 as well. That way the earliest any branch will start is when it was supposed to, but some will be delayed.

Noise

The properties in these groups add noise to the growth animation to provide a more organic effect.

Wobble

Amount

Controls how much noise is applied when bringing the orientation into its final position.

Note

The final value for the profile curve must be 0.0 in order for the model to exactly match its correct final position.

Frequency

Increases or decreases the frequency of the noise pattern used for orientation.

Speed

Amount

Controls how much noise is applied to the speed at which the branch reaches its final position.

Note

The final value for the profile curve must be 0.0 in order for the model to exactly match its correct final position.

Frequency

Increases or decreases the frequency of the noise pattern used for speed.

Seed

Change this value to vary the noise pattern.

Mapping

Animate texture

When enabled, the V texture coordinates move with the branch in the growth direction (think of a trunk that appears to be pulled out of the ground). When disabled, the texture appears to be revealed as it grows (the V coordinates are constant).

Animate displacement

When enabled, texture-based displacement moves with the texture map. When disabled, displacement is computed as it would be in the final model. Because displacement is continuous and only sampled at length segments, some artifacts may occur during the animation. Zeroing out displacement will eliminate these artifacts altogether.

Physics

The properties in this group are used to control attributes of the model used for physics simulation or character rigging in third-party applications.

Bone Style

Sets how bones are computed.

Property	Description
Absolute	The number of bones is explicitly set per-node.
Relative	The number of bones is based on the length of the spine.

Bones

Sets the number of bones generated along the length of spines based on the Style property above.

Note

If Bone style is set to Relative, this integer becomes a floating-point value and the actual number of bones generated is a function of the length of individual nodes.

Radial scalar

Scales the radius of the bones.

Length scalar

Scales the length of the bones.

Density

Affects the weight and stiffness of branch geometry in physics calculations.

Breakable chance

Sets the probability that the bones will break.

Lightmap

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

Weight

This value influences how much space in the lightmap branches made by this generator can have.

Use the distribution curve to control where the Lightmap UV density is applied. The default value packs more at the base than at the tip. Keep in mind that the Weight value is considered along with the geometry area and texture area of the object.

In addition, 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.

Geometry Force Crawling

The properties in this group control the behavior of branches when they collide with a geometry force that uses the Obstruct style for its Collide behavior.

Max iterations

When a mesh collision is detected, this property determines how many attempts are made to continue on without going through the mesh. More iterations mean a better chance of finding a route at the expense of slower computation times.

Max bend angle

Specifies the maximum amount a spine can bend to try to get around the mesh.

Tolerance

Sets how tolerant of collisions the algorithm should be. Larger values mean more of the branch will intersect with the mesh. Adding some tolerance often helps the look of things like vines clumping together.

Look ahead

The spine of the branch is computed/collided one accurate segment at a time. This property allows the mesh crawling algorithm to simulate a few steps ahead of where it is to avoid collisions with meshes. Increase this value to make branches avoid mesh collisions (even when they're attracted to the mesh) from a greater distance.

Hit backfaces

When enabled, collisions with back-facing polygons on meshes will count as a hit. When disabled, branches will pass through back-facing geometry.

Follow

When a branch contacts a mesh it has the opportunity to follow along its surface. The properties in this group control that behavior.

Strength

How much the branch will follow the surface. The direction computed for the following has to compete with all the other factors influencing the direction (e.g., gravity, other forces, early noise, etc.). Increase this value to increase the follow direction's effect on the branch.

Angle

Sets the clockwise angle from the default follow direction. The default follow direction is always the direction the V UV coordinate is increasing on the triangle that was hit.

Note

Meshes with UV islands may have wildly different follow directions on adjacent triangles. Consider other methods (like magnet forces) to control branches on such meshes.

Bounce

The properties in this group provide a mechanism for making a branch that is following a surface occasionally leave it and return. This technique can be useful for making vines crawl along surfaces realistically.

Chance

Increase how often a bounce may happen.

Strength

Controls how much the branch can bounce.

Recovery

Controls how fast a branch will recover from a bounce.

Variation

Adds variation to each bounce and recovery.

Noise

Use noise to make the following behavior vary across the surface.

Amount

Controls how much the branch will vary from the following angle.

Turbulence

Controls how chaotic the deviation from the following angle will be.

Seed

Randomize only the following noise behavior while leaving the rest of the branch unchanged.

Results

When a branch is set to collide with a geometry force, it will either fail or succeed in that effort. The properties in this section control what to do in either case.

Failed

Choose what to do when a branch is colliding with a geometry force but no solution can be found given the current settings.

Property	Description
Keep it	The branch remains. It may have errors but it will be in the model.
Prune it	Chop the branch off at the point of the error. The branch remains.
Stop it	Stop the branch at the point of the error. All of the profile curves will treat the branch as though the new length was its intended length. The branch remains.
Destroy it	The branch is removed from the model.

Succeeded

Choose what to do with the branches that worked.

Property	Description
Keep all	The branches will be kept and included in the model.
Keep hits	Only those branches that hit an enabled geometry force will be kept.
Keep misses	Only those branches that missed all enabled geometry forces will be kept.
Reject mesh escapees	Only branches that remained fully contained within an enabled geometry force will be kept.