MetaHuman Stylized Character - Character Geometry and Rig Creation

Have you ever wanted to create a stylized character for your Unreal Engine or UEFN project? This section of the MetaHuman Stylized Character tutorial covers the creation of the initial character mesh using the import From Custom Mesh option and the generation of the MetaHuman rig.

In this part of the tutorial, you will:

• Generate a working version of your character that uses MetaHuman mesh topology and UVs. Subsequent geometry work will use these meshes.

• Improve the MetaHuman geometry to better match the features of the source mesh.

• Generate an initial body mesh, rig, and skinweights, and transfer these to your clothing meshes.

• Ensure all working assets are on the default MetaHuman A-pose, as the input meshes may differ. This helps maintain mesh and rig alignment as you iterate through changes later.

Prerequisites

This is the first of a multi-part tutorial series that guides you through the creation of a stylized MetaHuman character. 

The MetaHuman Stylized Character tutorial shows how to convert your stylized character into a MetaHuman using MetaHuman Creator, and how to make the necessary changes to the rig and geometry to match your original design. You can follow the tutorial using your own character asset with the following guidelines:

• Your character is modeled in the A-pose rather than the T-pose. This does not need to perfectly match the MetaHuman A-pose.

• Your character does not need to use standard MetaHuman topology.

• Your clothing meshes should be on game-ready topology with baked textures.

Check out the end result of this tutorial by downloading the  MetaHuman Vampire Character Asset available on the Fab Marketplace.

For more information on the software and plugin requirements for this tutorial, see the MetaHuman Stylized Character Tutorial landing page.

Important Concepts and Features

Model-pose: The pose of the input character sculpted mesh. This can differ from the standard MetaHuman A-pose.

MetaHuman A-pose: The standard A-pose that is the reference pose for all MetaHuman characters. This ensures compatibility with MetaHuman animation assets and retargeting systems. This pose has the following general guidelines:

• All muscles are relaxed.

• Don't roll the shoulders forward.

• Don't rotate the wrist-to-palm forward (this activates muscles in the forearm).  Instead, pose them to rest naturally so the palm faces the leg.

U-dimensions(UDIMs): A UV mapping technique used in 3D texturing workflows to manage high-resolution textures.

Creating the Initial MetaHuman Character Asset

The first step to creating a stylized character is to import your custom character mesh into MetaHuman Creator and generate a working MetaHuman mesh with the correct topology and UVs. 

This mesh will be used throughout the rest of the tutorial.

To import your custom character mesh:

1. Create a new MetaHuman character in the Content Browser. Right-click in the Content Browser and select MetaHuman > MetaHuman Character.

2. Double-click your new MetaHuman Character to open the MetaHuman Creator window.

3. Click the Import button to the left of the window and click From Custom Mesh.

4. Click either the Full Character or Head and Body button, depending on your source mesh. For this example using the vampire, click the Full Character option. 

5. In the Combined Mesh section of the menu, open the dropdown menu and select your character mesh.

6. Click Auto Solve.

Using Auto Solve gives you an initial result, but some parts may still need attention. It captures the general body shape of the source character mesh but some details are lost — usually around the eyes, ears, lips, and mouth. 

Using the mesh options found in the Custom Mesh and MetaHuman Mesh options can help highlight these issues.

Enabling the Matcap texture options applies a guide overlay to the MetaHuman mesh that provides contour lines to help guide your adjustments and locate areas that need improvement.

You can improve the Auto Solve result by adding more preset keypoints. Preset keypoints are default landmark points that MetaHuman uses to guide the solve process. You should place the points so the contour lines roughly align with their anatomical counterparts on the source mesh. 

As an example, follow the steps below to improve the ears:

1. Rotate your view and zoom in so you have a clear view of one ear.

2. In the Import > From Custom Mesh panel, find the Keypoints section and enable Show Preset Keypoints.

3. In the Custom Mesh section, use the Mesh Offset to adjust the location of the source mesh so that you can clearly see the ear on both models.

4. Left-click to select a keypoint on the MetaHuman mesh. Find the corresponding point on the source mesh and press CTRL+right-click. Repeat this process to add more keypoints.

   

5. Click Auto Solve.

   

6. Once you have a solution for the ear that looks good, repeat the process for the other ear.

  Additional custom keypoints can also help the placement of the finger joints:

This results in joint loops that are closer to the original source mesh knuckle rotation. Notice the nails from the original sculpt were not captured here since MetaHuman Creator does not have that type of shape in the database for the solver to use. This is fixed later in the process in your 3D application.

With the adjustment to the MetaHuman mesh complete, save the result as a DNA file:

1. Click the arrow next to Manual Solve Actions to open the advanced options.

2. Click Save Pose.

3. Locate the new DNA.uasset in the Content Browser, right-click on it and select Export DNA.

4.   Choose a save location and name the file vampire_POSE.dna.

5.   Click Save.

Geometry Fixes and Improvements

It is likely that your new MetaHuman mesh still lacks many of the details of the original source mesh. When importing the mesh, you added additional keypoints to bring more definition to certain areas. To bring the MetaHuman mesh more in line with the original vision, you will need to continue to refine it in your 3D application. 

From this point forward, you will continue to work on the character face and body mesh using standard MetaHuman topology and UVs. When creating a stylised character with exaggerated form and shaping, it’s important to be mindful of the potential limitations of MetaHuman standard mesh topology and UVs in being able to represent these well. For example, care is needed for exaggerated ears and philtrum (the small vertical groove on the middle of the upper lip), pushing these areas too hard can result in noticeable UV stretching. 

Changing mesh topology (splitting polygons, creating or merging vertices) or UV layout could result in a mesh that is not valid for subsequent Import from Template Mesh steps. Edits that modify both will lose compatibility with MetaHuman Creator.

To start working on your character mesh, import the combined body and head DNA file that you created previously using the Save Pose option. For this example, you are using Maya with the MetaHuman for Maya plugin:

1. In Maya, open the MetaHuman menu and click the Pose Editor.

2. Open the File menu and click Import from DNA.

3. Navigate to the save location for vampire_POSE.dna.

4. In the DNA Import Settings, toggle the options Import Skeleton and Import Geometry to On.

   

5. Toggle the Z option to set the up-axis to the z-axis.

6.   Click Open.

   This DNA file can only be loaded with the Pose Editor in the MetaHuman for Maya toolset. You cannot assemble a character from it using the Character Assembler, which expects a complete DCC export package from MetaHuman Creator.

7. After it loads, you should have a scene with the combined mesh LOD0, its body Levels of Detail (LODs) located in the body_grp, and the rig.

   

8. Hide the LODs meshes.

9. Duplicate the combined_lod0_mesh, un-parent it from the group, and delete its history.

10. Apply the guide textures (available with the Metahuman Conform Topology asset from the Fab Marketplace) to combined_lod0_mesh for the Head and Body UDIMS by creating the materials and assigning it to each part.

    

Depending on your 3D application, you can then move the loops using sculpting tools and auto-project features (such as Live Surface in Maya or Project in Zbrush) to maintain the sculpt surface and preserve its forms.

You will also want to remove the excessive smile expression to keep it more neutral. The result should have smooth and fairly evenly spaced quads, and anatomical loops positioned for the best animation results.

Below is an example of work completed on the ears:

Below is an example of the work completed on the hands to adjust the knuckle edge loops and add the nails:

To complete the vampire look, import the base teeth (available with the Metahuman Conform Topology asset from the Fab Marketplace) and add fangs by using your sculpting tools to extend the canines, and adjust the shape to make sure they fit in the vampire’s mouth. Use Transform tools to make sure the teeth don't intersect too much with the lips from the inside.

Use your sculpting tools to extend the canines. Slide the slider to see the final result.

Bring all of the changes back into MetaHuman Creator:

1. Using your 3D application’s UV editor or material selection, select the polygons contained in the first UDIM shell. This will be the head. Extract them as a separate mesh and give the file an appropriate name.

2. Export each element as an FBX file and name them S_vampire_head.fbx, S_vampire_body.fbx, S_vampire_teeth.fbx.

3. Back in Unreal Engine, import the FBX files into your project.

4. In MetaHuman Creator, click the Import tab and select the From Template option.

5. Use the asset picker to assign your imported skeletal meshes to the Head, Teeth, and Body slots.

   

6. Enable Set Match Vertices to UVs.

7. Toggle all the options under Head Options to Off.

8. Disable Target Mesh is in MetaHuman A-pose.

9. Click Apply.

You now have your stylized character as a MetaHuman. 

Now, using MetaHuman Creator, create a full rig to get a full animatable character, it will also automatically pose it to a MetaHuman-compatible A-Pose. Click Create Full Rig and let the process complete.

Below you can see the different steps and compare them from left to right: 

With the edits complete, you can see the improvements. The initial MetaHuman mesh had the following issues:

• Brow had pinching in the center and was not taking the sculpted details.

• Ears were less defined, messy, and had some mesh intersecting.

• The mouth area always had the pulled shape of the smile even in a neutral pose.

• Eyes did not close properly and evenly.

• Nose shape wasn't well defined.

• Teeth were still the default human type.

After importing the improvements back into MetaHuman Creator:

• Brows had pinching in the sculpt shape and had a clear separation between the right brow and left brow.

• Ear shape is clean and defined, with no intersection or noise.

• Neutral mouth shape is more natural, and different from the smile shape.

• Eyes close evenly and don't have gaps when completely shut.

• Nose shape is clearly defined and follows more natural deformation due to correct loop placements.

• Mesh now has vampire teeth instead of the human ones.

Export the Fully Rigged Character

You will continue working on the character in Maya to update the clothing meshes, improve the facial expressions, and modify the body deformations.  To do this, you will need to export the character ready for use in an external 3D application.

1. Click the Export tab on the left side of the screen.

2. Select the DCC Export option.

3. Provide an External Path where you would like the files to be saved.

4. Click Export DCC Package. This creates a folder with the same name as your MetaHuman Creator asset which contains the DNA and texture files.

Once complete, a folder will be created at the External Path location that contains the head and body DNA and texture maps for the character.

Transfer Body Rig to Clothing Meshes

At this point, you should have an initial version of your character mesh in MetaHuman Creator. It is in a rigged state, with a standard MetaHuman A-pose, and with a body and face rig.

Next you will learn to transfer the body rig onto the clothing meshes, and ensure that all working assets are moved from Model pose to the standard MetaHuman A-pose.

Any clothing meshes are currently in Model pose. This does not exactly match the standard MetaHuman A-pose. To transfer the skin weights to the clothing meshes, you will need to import the DNA file you created from the Vampire DCC package export folder into the Pose Editor in Maya. This creates a scene with the full character mesh and with the skeleton and skin weights. You can then import your clothing meshes and copy the skin weights from the body to the clothing.

Be sure to test the resulting deformation, particularly in areas like the arm pits, and manually update the skin weights where needed.

The following steps cover how to copy the rig and skin weights onto the clothing meshes, and move them into the MetaHuman standard A-pose at the same time:

1. In a new Maya scene, import the body DNA file using the Pose Editor that you created as part of the DCC package exported from MetaHuman Creator. This loads the body of your character with the MetaHuman rig and skin weights in the MetaHuman A-pose. 

2. Save the scene and name it MetaHumanCharacter.ma.

3. In a new Maya scene, open the vampire_POSE.dna using the Pose Editor that was created using the Save Pose button in MetaHuman Creator.  This loads your character with the MetaHuman body rig and skin weights in Model Pose.

4. Import the clothing meshes for your character into this scene. As both the character and the clothing are in the Model Pose, they should already fit well.

5. Use Maya’s native tools to copy or transfer the skin weights from the MetaHuman body to the clothing. You will need to test the skin weight transfer by articulating the skeleton to review the deformations, making adjustments as needed. Pay particular attention to areas like the armpits, elbows, knees, and crotch.

6. Save the Maya scene and name it UpdatedModelPoseClothing.ma.

7. Reference the MetaHumanCharacter.ma scene saved in a previous step into the current Maya scene.

8. Move the clothing meshes from the model pose to the MetaHuman A-pose using the following approach:

   1. Using the referenced MetaHuman A-pose skeleton as a guide, reorient the clothing skeleton into a MetaHuman A-pose.

   2. Duplicate the clothing meshes to create new clothing meshes baked in the MetaHuman A-pose.

   3. Fix any model issues introduced while moving between poses.

   4. Save the clothing meshes as S_vampire_clothing.FBX. You will use this file later.

The result should be correctly aligned clothing meshes in the MetaHuman A-pose.

Next Steps

• 

  MetaHuman Stylized Character - Facial Rig Editing

  Improve the facial rig when creating a MetaHuman character.