Sugar Glider_Rigging

Some Notes on Rigging a Character with a Tail Using MetaHuman Armature

For this character, I used MetaHuman Armature as the base rig and extended the skeleton by adding a tail. The setup itself is relatively straightforward, but I ran into a few details that had a noticeable impact on the rig generation and automatic weighting, so I wanted to share some of the things I learned from the process.

1. Adding the Tail to the Spine

I parented the first bone of the tail to one of the Spine bones, while keeping its original offset.

One small but important detail is that, even though the offset between the two bones should be preserved, I found it helpful to keep the connection point between the bones properly aligned. This makes the relationship between the skeletons cleaner and works better with the later rig generation.

Then, in Pose Mode, I selected the first tail bone and set its rig type to Basic Tail.

By default, the Basic Tail setup uses X Axis Rotation. However, if you want the tail to be able to rotate more freely in different directions, I recommend enabling the Y and Z axes as well.

Once the rig control system is generated, the tail will automatically be included in the control setup. This means there is no need to manually create a separate set of controls for the tail.

2. Character Scale and Automatic Weights

Another interesting issue I encountered was related to the overall scale of the character.

At first, I modeled the character according to a relatively realistic animal scale. The character was only around 12–15 cm in size.

The rig itself could still be generated successfully, but when I tried to use Automatic Weights, the process failed and the automatic weights were not generated correctly.

I then scaled the character up to a little over 20 cm, and after that, Automatic Weights worked successfully.

I have not yet tested the exact threshold between these two sizes, so I cannot say what the minimum reliable size is. But based on this experience, it seems that making the character too small can cause problems with Automatic Weights, while using a slightly larger scale can make the process much more reliable.

It's a small detail, but definitely something worth keeping in mind when preparing a character for rigging.

3. Keep the Character in a Neutral Pose

Another thing I would strongly recommend is keeping the character relatively upright and neutral during the modeling stage.

For the tail in particular, it is better to keep it relatively straight instead of modeling the character with the tail already bent into its final pose.

In other words:

Build the character in a neutral pose → create the skeleton and rig → use the rig to create the final poses and animation.

This makes the rigging, weight painting, and animation process much easier to manage and gives you more flexibility later.

Final Thoughts

This project reminded me that even a relatively simple tail setup can involve quite a few small but important details:

Use MetaHuman Armature as the base rig.
Parent the first tail bone to the appropriate Spine bone.
Preserve the offset while keeping the bone connection properly aligned.
Set the first tail bone to Basic Tail.
Enable X, Y, and Z rotation if you want more flexible multi-directional tail movement.
Avoid making the character too small, as this may cause problems with Automatic Weights.
Keep the character in a neutral, upright pose during modeling, and avoid bending the tail into its final pose too early.

These are not necessarily the only or “correct” ways to approach the setup, but they are a few practical lessons I learned while working on this character. Hopefully they can be useful to anyone else experimenting with MetaHuman Armature and custom tail rigs.
welcome to my Ko-fi
ko-fi.com/yingxia