##### Tree Generator

The Tree Generator is the root node of any model. It controls various global parameters such as the initial radius, LOD settings, and leaf collision.

# Generation

## float Size Scalar

Scales the entire tree model, including the tree radius.

# Shape

## float Radius

The radius of the tree area.

## float Sink

The amount to lower the tree below the ground plane.

## float Roll

The amount to rotate the entire tree around the origin.

# Level of Detail

## boolean Enabled

Toggles level of detail preview.

Enabling LOD preview may slow down compute time.

## enumeration Preview Style

### Manual

LOD state is controlled with the LOD indicator in the tree window or via the CTRL + left-click key combo.

### Use near and far

LOD state is determined based on the camera's position between the near and far LOD planes.

## integer Count

The number of discrete 3D levels of detail.

## float Near

The distance from the camera to begin the initial LOD transition.

## float Far

The distance from the camera to complete the final 3D LOD transition.

## float Billboard Start

The distance from the camera to initialize fading the billboard.

## float Billboard End

The distance from the camera to finish fading in the billboard.

# Leaf Collision

## boolean Enabled

When enabled, leaf collision is active (either automatically or manually).

## enumeration Automatic

### None

No automatic leaf collision.

### Cull

Automatic leaf culling.

### Spread

Automatic leaf spreading.

### Spread then cull

Automatically spread, then cull leaves.

### Cull then spread

Automatically cull, then spread leaves.

## float Spread Factor

Distance to spread colliding leaves in order to reduce overdraw and z-fighting.

## float Cull Tolerance

The distance from the center of each leaf where colliding leaves are allowed (1.0 = the extents of each leaf).

# Degradation

## boolean Enabled

When enabled, various techniques are bypassed (and possibly resolution is reduced) to temporarily increase compute speed for high detail trees.

## boolean Allow Welding

When disabled, welding is bypassed in degradation mode.

## boolean Allow Leaf Collision

When disabled, leaf collision is bypassed in degradation mode.

Even though disabling leaf collision results in more leaf polygons, the tree will compute quicker since leaf collision is a bottleneck in the compute process

## percentage Segments Scalar

Scalar for reducing the cross-sectional segments globally across the tree while in degradation mode.

## percentage Frequency Scalar

Scales the frequency of generators that are the end of the topological chain (e.g. leaves), or any generator with its degradation style set to 'always'. Topological leaves often house the majority of generated nodes and thus are the slowest to compute.

# Interactive Degradation

## boolean Enabled

When enabled, the tree becomes degraded only while computing (while the left mouse button is held down). This adds to the interactivity of high detail trees.

## boolean Allow Propagation

When disabled, descendant nodes aren't generated while computing. This greatly increases the compute time for trees with large node structures.

## boolean Allow Skin Compute

When disabled, skin compute is bypassed and the tree is rendered as only a frame until the compute is finished.

## boolean Allow Welding

When disabled, branch welding is bypassed while the tree is computing.

Edits to welding parameters may be difficult to view interactively with this option disabled since the effect is bypassed.

## boolean Allow Force Compute

When disabled, manipulating force objects in the scene or editing force properties does not compute the tree until the action is over.

## boolean Allow Curve Edits...

When disabled, Moving points or handles in the curve editor are not applied to the tree until the movement is completed.

## float Segments Scalar

Scalar for reducing the cross-sectional segments globally across the tree while actively computing.

## boolean Low Detail Navigation

When enabled, panning, rotating, and zooming are greatly accelerated in the Tree Window by only drawing the frame.
Useful for when when working with high polygon tree models.

# File

## boolean Use Compression

Use this option to zip compress '.spm' files when they are saved to dramatically reduce the file size.

## boolean Embed Geometry

When this option is enabled, the geometry of the tree model is stored in the file alongside the procedural paramters used to generate it.

If you are using the SpeedTree SDK, you must have this option enabled.

## boolean Compute AO On Load

When enabled, ambient occlusion (AO) is computed once the tree is loaded. This option is disabled if 'Embed geometry' is enabled, since AO is saved with the gemoetry in that case (this is primarily for high detail trees not intended for real-time use).

## boolean Fix Leaf Winding

When enabled, leaf mesh vertex winding is adjust to match the average of the normals at each vertex so that two-sided lighting works correctly.

# Physics

## boolean Breakable

Controls whether or not the tree can break.

## float Joint Break Force Per Mass

A multiplier for the maximum linear and angular force that the joint between branches can withstand before breaking.

## float Joint Spring Per Mass

A per mass multiplier for the spring stiffness coefficient of the joints between branches.

## float Joint Damping Per Mass

A per mass multiplier for the spring damping coefficient of the joints between branches.

## float Branch Swing Range

A range to determine how much the branches are allowed to swing (in degrees).

## float Plastic Threshold Angle

The angle at which the branch will stay deformed if plastic deformation is enabled (in degrees).

# Custom

## string User Data (1-5)

Each tree model can be given up to 5 user data strings, which hold special information to be read by the SDK.