meta data for this page
This is an old revision of the document!
Branch Generator
The Branch generator creates 3D branch geometry. It is used for trunks, boughs, branches, twigs, roots, etc. The following sections detail each of the Branch generator's properties.
Generation
The Generation properties are described in full detail under 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 from the following options:
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 enable force is multiplied by this amount before being applied.
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
Use this property to set 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 checked, 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
This property 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 this property to increase how often a bounce may happen.
Strength
This property controls how much the branch can bounce.
Recovery
This property controls how fast a branch will recover from a bounce.
Variation
Use this property to add variation to each bounce and recovery.
Noise
Use noise to make the following behavior vary across the surface.
Amount
This property controls how much the branch will vary from the following angle.
Turbulence
This property controls how chaotic the deviation from the following angle will be.
Seed
Change this value to 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 from these options:
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 from these options:
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 all mesh escapees | Only branches that remained fully contained within an enabled geometry force will be kept. |
Hand Drawn
Convert to hand drawn
Pressing this button will convert a procedural branch into a hand-drawn branch. During the process, some properties, such as “Allow forces,” are disabled to provide a more seamless conversion.
Note: Converting to hand-drawn may result in a slightly different branch.
Random Seeds
Properties that have variance are given random values based on a seed value in this group. Vary the seeds in this group to randomize only the properties associated with the seed type.
Randomize All
Randomizes the value for all seeds used to compute this generator.
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
This value 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.
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 from the following options:
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 segments are computed from the following options:
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. |
Weld Scalar
Adjusts the number of segments composing the fused part of welded branches.
Optimization
Segments are removed adaptively 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.
Resolution
The properties in this group scale the number of segments based on the selected resolution (“High”, “Medium”, “Low”, “Draft”).
Length
Scales the number of length segments for each Resolution.
Radial
Scales the number of radial segments for each Resolution.
Note: Resolution curves are applicable only to the VFX line of SpeedTree products.
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 simply 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
Feature vertices from the material's meshes, if present, will be added to the branch when this property is checked.
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 %
Use this property to control 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
This property 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 preserver branch shape, especially on low polygon count models.
Style
Choose how vertices are added in from the following options:
No new segments | No new vertices are added. This sytle is most appropriate on high poly 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 maintaing their roughly cylnidrical shape even when feature vertices are used on low poly 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.
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
This property scales the length of spines under shape control. The length value computed by the shape algorithm is multiplied by this value before it is used.
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
Uniform rotation of each branch. Roll is applied 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 do not 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
Use this property to control the amount and shape of the deformation. The value sets the amount and the profile curve sets the shape.
Twist
This property 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
Use this property to shift 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 cause 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 in order 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
This property controls how much the branch moves toward the shape computed by the jink algorithm. A value of zero keeps the branch as it was. A value of one 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, from the following options:
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. |
Mesh | Branches are constrained to the mesh that is imported. |
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 from the following options:
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 influence 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
This property sets the style of the skin from the following options:
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 their parent's radial size at the point where the branch is attached. This value is added to the “Absolute” radius above to set the final radius value.
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 impossibly thin branches.
Note: A value of 0.0 will disable this feature.
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
Vertices around curves and bends are pushed out in order 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 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.
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) set 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 and 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 of the split branches away from the center of the tree.
Side 2
Controls the angle of one 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 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 from the following options:
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 map 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 from the following options:
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 one 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 from the following options:
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.
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.
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.
Override V Coords for Extensions
Branch extensions typically continue their parent's V coordinates. Enable this option to allow you to set them explicitly instead.
Note: A common use for this option is using a trunk and two extensions to create a material transition. Create a base trunk with V coordinates anchored at the end, then add an extension with this option enabled. Put a bridge material on this extension knowing that it will always match exactly with the base trunk's V coordinates. Add another extension to complete the transition.
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] from the following options:
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 in such a way as 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).
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
Set the amount the vertices will move in the direction of the spine. Setting this value to anything other than 0.0 will result in vertices that share V texture coordinates no longer lying in the same plane.
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.
Source
Selects the source of data for the displacement from the following options:
Noise | Uses noise for displacement. |
---|---|
Material | Uses the map in the height channel of the assigned material for displacement. |
Displacement Asset | Uses a named displacement asset as the displacement source. |
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 one will push the displacement outwards and less than one will bring the displacement in towards the center of the branch.
Shape
This property adds length creases, following the direction of the spine, to break up the branch radius. It's 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
Change this property to vary 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
Set 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
Change this property to vary 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
This value 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.
Wind
The properties in this group control the wind behavior of the branch. How this data is used depends on the chosen wind algorithm (which may be determined automatically by the version you are using).
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
The properties in this group control how the wind weight is computed for this branch.
Style
Choose the method by which weight is computed from the following options:
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.
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.
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 sytle
Choose how the radius is treated from the following styles:
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
This profile curve 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
Check this box to have growth timing apply 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. Options include:
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 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 perfect 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 as described above.
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 from the following options:
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.