Rigging

Skeletons are made of bones, which are composed of a tail, a body and a head.

Bones can be extruded out of tails of other bones with E while in Edit mode. Alternatively, you can scale up a bone and then subdivide it to break it down into multiple bones.

Rotating bones in edit mode makes them rotate around the body center if the pivot point is set to bounding box.

However, rotating in edit mode does not modify the local object orientation (which can thus stay aligned with the global orientation), while rotating in object mode will also rotate it's local orientation.

Use the 3D cursor as a pivot point to handily rotate a bone or armature in edit mode.

When selecting bones, there is an additional Pose mode available on top of the Object and Edit modes.

In Pose mode, bones will rotate around the head joint. G to grab any child bones will make them rotate around their head and not move. Only the top parent bone can actually move.

Duplicating a bone in edit mode and moving it outside the armature will keep the parent/child relationship but the separated bone can be freely moved around.

You can clear parents with ALT + P or reparent bones together with CTRL + P. When parenting bones there is an option to either keep offset (if the bone is moved away from the selected parent) or connect (to snap the bone head to the parent's tail).

When several bones are stacked on top of each other ALT + LEFT CLICK opens a selection menu to choose which bone to select.

Even in pose mode, scaling will act like a normal parenting relationship and scale the children as well.

When swapping between Edit and Pose mode, the Edit mode will conserve neutral position of bones while the Pose mode will conserve the way the bones were moved.

The ALT + G / R / S hotkeys are handy to remove any movement/rotation/scale applied to a bone hierarchy and reset the pose mode.

When in Pose mode of a hidden armature, it's not possible to select another armature. Toggle back to Object mode to do the swap.

It's best to Apply scale before parenting a mesh to an armature.

Keeping a slight bend on arms and legs can help a lot in the rigging process.

Bones can be made to display on top of meshes in Data > Viewport Display » In Front.

Meshes are attached to the bones following the same parenting process CTRL + P as with meshes.

Bones attach to the mesh's vertices (Vertex Groups), so take care the mesh has enough topology to follow the bones movements and rotations.

Remember when creating an armature to check and adjust the bone roll for each bone depending on how the bone is meant to rotate around it's joint.

Often the Z will be facing forward (but not always) and most of the time the X will stay parallel to the global X.

It's generally useful to have a root bone aligned with the World origin and have that at the top of the hierarchy.

The Root bone's function is generally to move the character around in 3D space while animating a walk cycle for example.

On humanoids, it's also more convenient to have a hip controller sticking out the back to move the upper part of the character rather than having to select the lower spine.

In terms of parenting, the hip controller should be parented to the root bone as well as any IK target, and the IK pole should be parented to the IK target to keep it always in front of the IK rig part.

Controller bones (root bones, targets, poles, etc.) should not deform the mesh. Take care to select them and under Bone Properties uncheck Deform

Once that is done, select the entire armature and RIGHT CLICK > Symmetrize.

Snapping to Volume can be handy to get the bones to attach to the proper points of the mesh.

You can attach separate objects to a same armature (handy for clothes, backpacks, weapons, etc.)

When doing a humanoid basic rig, it's handy to do one side in front view then mirror to the other side.

The naming convention .L or .R after the name of each bone helps Blender rename correctly the other side when the mirror is applied.

To rig a basic humanoid, it's useful to have it in a T shape pose facing forward.

Weight painting controls the Vertex Groups for the different bones of a skeleton attached to a mesh.

In Edit mode, selecting individual vertices will display the vertex group influences under the Options (N) > Item tab.

When going into weight paint mode, select the entire armature first, then the mesh, then go into weight paint mode. If you only select the mesh it will only display the weight paint of the last selected bone.

This way you can ALT + LEFT CLICK the different bones to see their influence. It's possible in weight paint mode to select a bone and rotate it to visualize the influence it has on the mesh.

The color gradient indicates each selected bone's influence on the mesh : red for 100% attachment to vertices and blue for 0%.

When weight painting do not confuse the Weight property (ink color) to the Strength property (ink flow)

When weight painting, a part of the mesh can be influenced by different parts of the armature.

Weight painting for one part of the armature does not remove the influence from the other parts.

Under the Options menu tick the Auto normalize option to limit to 1 the influence applied to the vertices of the objects.

This will effectively remove the influence of other bones when painting up to 1 on a mesh for a given bone.

Use a combination of:

• Paint to directly apply a quantity of influence
• Smear to smear one influence into another
• Blur to even out the influence transitions.