Automatic from Bones

The weights are generated from the Skeleton topology. Blender tries to predict how the bones need to influence the meshes and calculates appropriate weight maps for all deform bones.


  • Selected Deform Bones
    Create Weight maps for the selected bones(1).
  • Visible Deform Bones
    Create weight maps only for the currently visible bones(2)
  • Enabled Deform Bones
    Create weight maps for all bones enabled below

(1) Selecting Bones: Select the Armature in pose mode and select all bones you want to get weighted. Then select the mesh for which you want to get the weight maps

(2) Make Bones visible: You can hide/show bone groups using the Rig Display panel. Or you can open the Armature in pose mode and hide individual bones (use “h” to hide selected bones and “ALT h” to make hidden bones visible)

Enabled Deform Bones

The content of the created weight maps is highly dependent on which bones are treated as deform bones (bones which actually can influence the meshes by using weight maps)

For more about Targets and Sources see next chapter below

By default only the SL Base bones (the legacy skeleton) is enabled. For Extended (Bento-) Rigs also the Hands and Face bones are enabled by default. But you can change this configuration in the Deform Groups Section (see image)

Note: The setting here only controls the behavior of the Weight generator! otherwise this setting is completely independent from what you have configured elsewhere in Blender (either in the Rig Config panel, or in the Bone properties window) .

Important for Automatic from Bones): Please keep the Volume bones disabled when you use the Automatic from Bones strategy. Otherwise the generated weight maps will become totally wrong for this case.

Important for Facemap Generator): Please enable the Face bone group when you use the Facemap Generator strategy. Otherwise the generated weight maps will become totally wrong for this case.

Targets and Sources

Below the strategy selector you find 2 text lines:

  • Target maps are the weight maps the will be created.
  • Source bones are the bones which are considered to be deforming the Mesh

The content of the 2 lines depends on

  • the Scope
  • the Bone deform Groups you have enabled
  • The visible/selected bones

The first line:

In this example we have chosen the scope Selected Deform Bones. However we have not selected any bone, hence No target map found. Fix: Enable at least one bone that is a member of one of the enabled deform groups.

The second line:

Here you see the number of bones that are contained in the selected deform Groups.

Hint: When the scope is Enabled Deform Bones, then the number of target maps is identical to the number of Enabled Deform bones!

In this example we have selected the legacy bones and the SL Eye bones, hence we get maps for 26 bones.

Generator options

You have further options to specify what exactly the generator shall create for you. See below for a more detailed description


Makes sure that when you have selected bones only from one side of the rig, the bones on the opposite side are also included even when not selected.

Note: Known glitch in Avastar-2.5: The number of target maps found currently does not count deselected mirrored bones, however the generator still creates the mirrored maps as expected.

Keep empty Maps

The generator always creates all Target maps, even if they turn out to be empty. Normally you do not want to keep empty weight maps. However this option allows you to change that at will

Clear Target maps

When enabled then the weight maps are cleared from all weights before the weight generator adds new weights to them. This is ideal when you want to renew entire weight maps.

However sometimes you want to recreate the weights only for a subset of selected vertices (see next option). In that case you may want to keep the weights of the deselected vertices unchanged. In that case you will disable this option.

Selected Verts

Generate weights only for the selected vertices. This allows you to fine control for which exact parts of your meshes weights are generated or regenerated. Please take into account the previous option above.

Trouble shooting

Failed to find solution…

The automatic weight from bones algorithm normally creates reasonable initial results. However, sometimes the heat algorithm does not claculate weights for a subset of the mesh vertices. And sometimes it even rejects to create weights for the entire mesh.

There was a topic about this on Blender stackexchange: See fails to find solution for one or more bones…

Here are some tips how you might get rid of the issue:

  • Fix duplicate vertices
  • Fix mesh polygon intersections.
  • If the mesh object has 2 or more unconnected submeshes, then try to split the submeshes into separate objects, then weight again and finally join the submeshes back into one single object
  • Check if the Mesh uses modifiers (e.g. subdivision). Disable the modifiers before binding, then add them back after binding.
  • Check if the bone deform flag is set for all bones where you expect to get weights.
  • Be sure you are not selecting the green animation bones or the yellow IK bones . Remind: the green bones are only used for Animation. They should never have weight maps.