Leaf generator
This generator has been deprecated. Go to the current version or learn how to upgrade an old model.
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.
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.
Placement
Weld
When enabled, leaves will be placed directly on the skin of their parent, rendering "Max" and "Min Distance" disabled. At the same time, "Surface Adhesion" becomes enabled.
Unify Orientation
Forces leaf nodes on opposite sides of their parent to be oriented in the same direction. Rotation adjustments like "Up," "Right," and "Out" keep opposite nodes synchronized when this option is enabled. This option is especially useful when modeling opposite or alternating phyllotaxis.
Surface Adhesion
Orients the leaves by interpolating between the internal "up" direction of each leaf (0.0) and the normal of the parent surface (1.0).
Max Distance
The maximum distance from the parent spine where leaf nodes are eligible.
Note
If "Generation:Style" is set to relative, increasing this property results in higher leaf node frequencies in order to ensure full canopy coverage.
Min Distance
The minimum distance from the parent spine where leaf nodes are eligible.
Exponent
The exponent applied to the computed placement distance. Greater values will pack leaf nodes near the parent spine and vice versa.
Angle
The angle between the parent spine and the vector used to offset each leaf from the parent spine.
Spread Scalar
Scales the spread factor value set in the leaf collision properties.
Cull Scalar
Scales the cull tolerance value set in the leaf collision properties.
Note
Spread and cull scalars have no effect in SpeedTree 8.0 and later.
Edit Leaf Collision…
This button has no effect in SpeedTree 8.0 and later.
Leaves
Size
The size of the leaf nodes.
Use Actual Size
When enabled, the size parameter is ignored and the mesh is used at exactly the size at which it was modeled.
Flip
When enabled, randomly-selected leaf nodes are flipped over the Y-axis.
Type
Multiple leaf types can be defined and applied to nodes at random. Use the button controls to add [+] or remove [-] leaf types.
| Property | Description |
|---|---|
| Geometry | A named mesh from the mesh bank will be used for this leaf type. A value of "none" results in a plane being used instead. |
| Material | A named material from the material bank to be applied to this leaf type. |
| Weight | Probability that any node will receive this leaf type (this weight ÷ sum of all weights). |
Cards
Aspect Ratio
The aspect ratio of leaf cards (width ÷ height).
Jitter
The amount of offset for each vertex from its default position.
X Pivot Offset
The horizontal distance from the center to position the leaf pivot point.
Y Pivot Offset
The vertical distance from the center to position the pivot point.
Meshes
Orientation
Selects how the leaf meshes will be oriented from the following options:
| Property | Description |
|---|---|
| Default | Uses SpeedTree's traditional algorithm. |
| Sky sensitive | Orients leaves based on their position relative to the sky and the tree structure. |
| Camera facing | Leaf meshes are oriented to face the camera at all times, exactly like a leaf card. However, camera-facing leaf meshes can take advantage of optimized geometry to reduce overdraw and costly transparent pixels. |
Sensitivity
Parent
Controls how much the leaves are aligned based on where they have grown on the model. Higher numbers result in localized orientations. Lower numbers result in a more global effect.
Sky
Controls how much the leaves point toward the sky. Higher numbers result in the Z axis of each mesh pointing straight up. The more sky sensitive a leaf is, the less parent sensitivity plays a roll in its orientation.
Alignment
Attempts to align the top of each mesh with the world "up" direction while respecting the existing Up Rotation. Used to eliminate upside-down meshes.
Hang
Interpolates mesh orientation between the local Z-axis (0.0) and the world Z-axis (1.0). (Percentage)
Up Rotation
Rotates each mesh around the local X-axis.
Out Rotation
Rotates each mesh around the local Z-axis.
Right Rotation
Rotates each mesh around the local Y-axis.
Jitter
The amount of offset for each vertex from its default position. Jitter is applied differently per leaf.
Lighting
Global Style
Chooses the algorithm used for calculating the "Global Smoothing" anchor point from the following options:
| Property | Description |
|---|---|
| Parent curve reference | Uses SpeedTree's traditional algorithm based on parent curves. |
| Anatomical anchor | Uses a value based on the distance to the ground along the parent branch's anatomy. |
Global Reference
The position along the assigned parent level used for calculating "Global Smoothing."
Note
If "Extras:Hints" are enabled in the Tree Window, the global reference points are drawn as orange cross-hairs on the assigned parent level.
Global Anchor
The percentage to ground along the parent branch's anatomy where the anchor point for "Global Smoothing" is computed.
Note
If "Extras:Hints" are enabled in the Tree Window, the global reference points are drawn as orange cross-hairs on the assigned parent level.
Global Smoothing
Interpolation between globally smoothed (1.0) and locally smoothed (0.0) leaf normals.
Global smoothing aligns leaf normals with the vector drawn from the Global Reference position to the leaf position, resulting in a predictably smooth lighting gradation.
Local Smoothing
Interpolation between locally smoothed (1.0) and individual node (0.0) leaf normals.
Local smoothing aligns leaf normals with the vector drawn from the percentage along the parent spine where the leaf node occurred to the leaf node position, resulting in a staggered lighting gradation.
Card Smoothing
Pushes leaf card normals away from the center of each leaf card.
Puffiness
After all normal adjustments have been performed, this value "sphere-izes" the normals around the pivot point, giving the geometry a more puffy appearance.
Range
Range controls the maximum range that normals are allowed to span vertically. A linear growth curve uses the entire range from normals pointing completely down to normals pointing completely up. Raise the low end to keep leaves from having normals that point straight down.
Ambient Occlusion
Dimming
Uniformly darkens interior leaf nodes.
Wind
Scalar
Scalar for wind motion from the center of each leaf (profile curve) and for the generator as a whole (parent curve).
Group
Selects a "wind group" that this generator belongs to. On the global wind properties, there are two distinct wind groups, each with their own set of property values. This is useful for modeling an alternate leaf wind type (for objects such as hanging moss or flowers).
Edit Global Wind
Selects the fan object, allowing the alteration of all global wind settings.
Level of Detail
The properties in this group are ignored in SpeedTree 8.0 and later.
Growth
The properties in this group are ignored in SpeedTree 8.0 and later.
Season
The properties in this group are ignored in SpeedTree 8.0 and later.
Lightmap
Weight
Scales all of the geometry in this object's relevance in the automatically computed lightmap UV set. Keep in mind that the scale value is considered along with the geometry area and texture area of the object. In addition, every object's lightmap scale is compared to every other object and then the lightmap packing is determined. This means that your scale 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.