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Shell Generator

The Shell generator is a special case version of the Branch generator. It exists only to duplicate a portion of its parent branch at a slightly wider radius. This extra geometry can cover all of the parent or only part of it. Use this generator to provide a thin layer of a different bark material around a branch.

Only the properties presented below are editable on shells. The rest of the shell's features are copied from the parent branch.

UV Mapping

The properties in this group control the UV coordinate generation.


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].


U coordinates circle the branch.


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.


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.



Sets the number of full revolutions to twist the material per V tile.

Random Flip

Randomly flips the texture twist direction.


V coordinates run along the branch.


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.

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.

Controls the amount of V tiling.


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.


The properties in this group control the material assignments.


Applies a material to the branches in this generator. Use the button controls to add [+] or remove [-] materials per geometry type.


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.


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.


Lightmap UVs are computed for several versions of the Modeler designed for use with game engines. Lightmap UVs are a UV set where no objects overlap and all of them fit in a single space where U and V fit in the range [0.0, 1.0].


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.


The properties in this group control how much of the parent is covered by the shell and how much wider the shell is than its parent.


This value controls how far up the parent the shell goes. 0.0 means cover none of it and 1.0 corresponds to fully covering the parent.

Note: You can use opacity maps on the shell material to allow the parent branch material to show through.

Controls how much wider the shell is than the parent (in terms of the parent's radius). Use the profile curve to vary this value along the shell.