Generators

Procedural modeling involves editing a variety of parameters and their variances that govern the creation of a model. Generators are the objects that provide this level of procedural generation.

Generators create and control groups of nodes, which comprise the geometry of the model. Editing the values and variances of the properties of the generators and controlling their hierarchy controls the procedural generation of the model.

Manage generators at a high level from the Generation Editor.

There are several types of default generators that create different geometry in the model, including generators for main components of the model, decorations, and photogrammetry elements.

When you add a generator to a model, you can add a default generator or you can add a template that consists of one or more generators with preset properties. For example, you can add the default Branch generator or you can add a Trunk, which consists of a Branch generator with values preset to look like a trunk.

Decorators are a way of spawning exterior parts to give a tree interesting and unique features.

	Cap generator The Cap generator closes off open-ended branches.
	Decal generator The Decal generator wraps a material with a flat mesh onto a parent to create surface details such as knots, lumps, or cavities.
	Fin generator Fin generators create a thin flap of geometry that can be used for fungus, moss, or other things that hang off a trunk or branch.
	Knot generator The Knot generator creates an extra piece of geometry attached to a branch, such as a knot, lump, or cavity.
	Shell generator The Shell generator creates a special kind of branch that sits on top of the parent branch, allowing you to wrap the parent in moss, algae, or low-poly vines.

The generators in this group provide the mechanism for using scanned 3D assets as part of the model.

	Mesh generator The Mesh generator allows imported mesh assets to be used as part of the model and operated on by the photogrammetry tools.
	Mesh converter generator The Mesh converter generator provides a set of tools for creating tiling map sets and native SpeedTree geometry extensions on meshes.
	Mesh detail generator The Mesh detail generator creates surface details from a material and a 3D mesh and blends those details into the parent.
	Stitch generator The Stitch generator joins native SpeedTree geometry to meshes.
	Target generator Target generators are used to precisely locate children off any parent.

The generators used in SpeedTree versions 5 through 7 are now considered legacy generators. They’re still available in the current version, but they’re not fully functional with new systems and are not guaranteed to remain available in future SpeedTree versions. They are included primarily so that old models can be loaded and upgraded to use new generators instead.

The table below names each legacy generator and their replacements.