Corrections Section

• Merge Rigs: Merge all selected armatures with the active one.
• Apply Rest Pose: Apply the current pose as rest pose for the selected armatures and their child meshes.
  
• Eliminate Empties: Remove superfluous empties in the imported scene.
• Merge Toes: Merge the individual toe bones with the main toe bone. Useful if you don't need to control the individual toes separately, e.g. if the character wears shoes.
• Add Extra Face Bones: In Genesis 3 and 8 characters, expressions are poses for bones in the facial rig. The face bones then become driven by rig properties and cannot be posed freely. This button add an extra layer of face bones which can be posed freely on top of the driven bones.

Merge Rigs

 

When the character is first imported, each piece of clothing is equipped with its own armature, which may be parented to the main character rig.

 

Normally we want to join all armatures which control both the character and all clothes. The Merge Rigs button merges all selected rigs to the active one. Since the main character rig is active after import, the quick way to do this is to press A-key twice (to deselect and select everything) and then press Merge Rigs.

• Clothes Layer: Bone layer for extra bones added by clothes.
• Separate Characters: Don't merge unparented rigs. Use this in scenes with multiple characters, to merge clothes rigs to the right humans.
• Apply Rest Pose: Apply the current poses of all selected rigs as rest poses before merging rigs. 
• Create Duplicate Bones: Create separate bones if several bones with the same names are found.
  
• Create Mesh Collection: Put the meshes in a separate collection. This is useful for excluding all meshes from the scene to increase performance when loading poses.

When the character is imported into Blender, the bones are put on bone layer 1. The clothes may add new bones to the armature, and we now get to choose on which layer to put them.

 

We see in the outliner that the rigs that were parented to Aiko have disappeared, and that the meshes are now directly children of the Aiko rig. On the clothes layer 3 there are two new bones which come from the skirt armature.

Note that all meshes has been moved to a separate collection. This allows you to temporarily exclude all meshes from the scene in a simple manner, leaving only the armatures. This is convenient e.g. when loading poses and animations, because most of the time is spent on updating the meshes, which is avoided if they are excluded from the scene. E.g., when loading a bvh file with the BVH retargeter, excluding the meshes from the scene can reduce the loading time with a factor of ten or more.

 

Apply Rest Pose

Sometimes it is necessary to apply the current pose as rest pose before merging for some of the armatures, but not for all. We can then use the Apply Rest Pose button. It differs from the standard Blender tool in that it also changes the meshes that are parented to the affected armature.

Import Aiko with Mesh Fitting set to one of the Unmorphed options. Then the foot and the sandal have different rest poses. The foot is posed to fit into the sandal, but since the sandal inherits the pose from the foot, the pose is applied twice to it.

We fix this by making the foot pose as the character's rest pose. The sandal rig must not be selected, because we don't want to change its rest pose. Nothing moves in the viewport after we use the Apply Rest Pose Tool, but the tip-toe pose is now Aiko's rest pose.

When we now Merge Rigs, the sandal jumps into position.

 

Eliminate Empties

Some assets create empties that are not really useful in Blender but mostly in the way. A typical example is this jacket with buttons, where each button consists of a mesh that is parented to an empty that is parented to a bone.

The Eliminate Empties tool removes this extra layer of empties. Select the parent armature and press Eliminate Empties. The empties are gone and the meshes are parented directly under the bone. Eliminate Empties can be done before or after Merge Rigs. Or not at all if you wish to keep the empties.

Other vendors implement jacket buttons as empties that are instanced to a mesh. Instanced empties are important because they show up in renders, and therefore the Eliminate Empties button does not remove them.

Merge Toes

When the rigs have been merged, we often want to merge the toes. Since Aiko is wearing shoes, there is no reason why we should want to pose the toes individually, so we press Merge Toes to let the big toe bone control all toes.

Add Extra Face Bones

We often want to import facial expressions, as described in the Morphs section. The bones in the face rig then becomes driven by object properties and can not be posed freely.

To make it possible to pose the face bones on top of loaded expressions, press the Add Extra Face Bones button.

For each bone in the face rig, a new bone is created on layer 32. The new bone's name ends with "Drv" (for driven).

 

The original are now parented to the new bones. When expressions are loaded later on, the "Drv" bones will be driven by rig properties, whereas the deform bones are freely posable. The idea is to first pose the face with a generic expression, and the tweak the expression with the posable bones to make it unique.

Note that the original bones remain green, because they have constraints that limit rotations and locations, whereas the driven bones have not constraints and are therefore white.