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Leaf Generator

Note: This generator has been deprecated. Please upgrade these generators to Leaf Mesh generators.

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.

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:

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 role 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:

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.