Overview

There are so many ways to tackle rigging and the subsequent weight painting, that it can get overwhelming quite quickly. Not only that, but depending on what the character is meant to be used for, the rigging process may change as well.

This page will focus on how to create a rig, for either a quick portfolio shot and animation in software like Marmoset Tollbag, Blender or real-time interactive viewers like Marmoset Viewer and Sketchfab, as well as making it game-ready for Unreal Engine 5. The focus will be on humanoid characters, but the same principles also apply to non-humanoid creatures.

One last note before we get started, it’s quite likely, that a lot will change in regard to rigging workflows for games, as the Unreal Engine team is currently working on a built-in, full encompassing rigging and weight painting system. Here them showcasing their progress on that (late 2023):

Software & Tools

The two main software used for professional rigging are Maya and Blender (and potentially soon Unreal Engine as well). For now, I’ll only cover the rigging process in Blender, but will be adding the Maya approach in the future. For a smoother and more efficient experience, I recommend some add-ons:

  • Rigify (A Blender built-in add-on for generating basic bones structures and control rigs)
  • X-Ray Weight Paint (A free essential weight painting add-on, which allows for painting through the mesh.)
  • Game Rig Tools (A free add-on which helps with making control rigs game-ready)
  • Send to Unreal (To quickly preview changes done to the rig in Unreal)
  • Voxel Heat Diffuse Skinning (A paid add-on which improves and adds to Blender’s automatic weights algorithms. This add-on is definitely not needed as I find that doing weights fully by hand is anyway better, but if you want to start with automatic weights as a base, then this add-on will save a lot of your time. There’s also a free version which doesn’t add any new algorithms, but prevents the bone heat weighting error from appearing.)
  • BatchOPS (If you end up wanting to change or add things to your rig, then this add-on will be a lifesaver.)
  • UEFY 2 (A very complex but powerful Blender to Unreal pipeline add-on worth mentioning. I however currently don’t use it in my workflow.)

I don’t recommend using Auto Rig Pro, which is a paid alternative to Rigify, if you plan on making the rig game-ready, as there are a lot less resources and tools covering the process with that, and it’s already hard enough as is with rigify.

Resources

The Maya rigging wiki is a massive and very helpfull resource even for non Maya users.

Some other interesting pages are:

Here are also some relevant videos, but I recommend looking through them after you’ve finished reading the rigging page.

Rig Types

There are three types of rigs: Meta-rigs, control-rigs and game-rigs.

First, the meta-rig is created which is basically a blueprint that defines what bones the character has, where they are located as well as what the bone chain relations look like (through parenting). The meta-rig also stores all the rig’s preferences.

Next, the control-rig is generated using the meta-rig as a blueprint and then bound to the character through a process called weight painting. The control-rig’s purpose is to provide the artist with complex and comprehensive shematics which allow for easy posing and animating of the character.

Finally, the game-rig is generated from the control-rig or meta-rig. The game-rig also needs to be bound to the character with weights. Everything necessary like animations and shape keys are then baked into the game-rig. Lastly, the character and the game-rig are exported into Unreal Engine via a FBX file.

Both the meta-rigs and game-rigs will only have very few bones, while control-rigs will be made of many colorful shapes.

You might have noticed a problem with what I just said, the control-rig and game-rig, both want to be bound to the character mesh. This however isn’t possible in most software, and Blender can only have one rig bound to a character at a time. So one can’t easily switch back to the control-rig if one wants to add an animation or tweak the rig. Depending on the workflow that is being used, there are a couple of ways of fixing it, one being the “Switch Parent Armature” option, that comes with the Game Rig Tool add-on, more on that later.

What Makes Game Ready Rigs Unique

Rigs are usually made up of multiple parts, the deform bones and the controls. The deform bones are bound to the mesh with weights and are able to manipulate the mesh. The controls on the other hand are only there to help pose or animate the character and only ever manipulate the mesh indirectly through the deform bones. Some examples of the control rigs features are IK (Inverse Kinematics) and FK (Forward Kinematics) setups or poles that tell the knee or elbow in which direction to point. Game engines, however, only require the basic deform bones and in a specific hierarchy and thus aren’t able to use the control-rig.

When looking at other artist’s workflows, you might notice that many of them use the rig that comes with UE5 and weight paint it onto their character. Although in theory this might be a great way of doing it, as one ensures that Unreal Engine will fully understand the rig, in practice this is a terrible approach as it will not allow you to pose or animate your own character properly. You’ll only be able to use poses and animations made by others, as well as having to go through the pain of exporting the rig from Unreal if you want to render in other software. This is because it’s currently not possible to generate a control-rig from the UE5 rig. And posing or animating without a control-rig is a waste of time and will not yield good results. (This is as of May 2024, I’ll try to update this part as soon as something changes in regard to this situation.)

So that leaves the question, what is the correct approach? The most optimal way of giving the game engine what it wants and not sacrificing the artist’s posing and animating experience, is by first creating a versatile control rig, weighting it, creating poses or animations and then stripping it of all its features right before importing it into Unreal while also baking the created poses and animations onto it.

The disadvantage of this approach is that one won’t be able to use the stock UE5 player controller animation system like running, jumping or poses and animations by others on the Unreal marketplace, without first retargeting the game-rig you created onto the UE5 stock game-rig. Retargeting is a one time process which can be a somewhat tedious and convoluted, but I’ll cover it here as simple as possible. (This again is something that I’m very sure will be automated by a script in the near future, removing the need for retargeting by hand when using a standardized rigify control-rig. And I’ll update this as soon as that’s available).

Let’s quickly cover what exactly either won’t transfer over, or needs to be adjusted before importing into Unreal Engine:

  1. As already mentioned, bones that don’t deform the mesh won’t be wanted in a game engine. In Blender the control rig is made up of many non deforming bones with fancy shapes, whereas other software like Maya uses empties instead to represent non deforming bones. These should not be exported to Unreal. (In Blender one can check if a bone is a deforming bone under the Bone tab. One can toggle bone deform for an entire rig or only specific bones in the rig.)

  2. Rig hierarchy is derived from bone parenting and doesn’t matter in Blender and Maya. Games engines however are quite specific when it comes to the rig’s hierarchies. Unreal Engine wants every rig hierarchy to start with a bone called “root”. More on what the exact hierarchy should look like later.

  3. Shape keys aren’t directly transferable to Unreal and need to be baked into the animation first, which means that the animations that used the shape keys will be fine, but one won’t be able to tweak the value of the shape key on the fly as it doesn’t exist in Unreal anymore. (Shape key baking is done automatically in Blender at export via the ??? option.)

  4. Squash and stretch with squishy bones won’t have the same visual result in Unreal Engine as in Blender, because Unreal Engine preserves the volume of the mesh, meaning the mesh will taper when stretched whereas Blender won’t taper the mesh when stretched.

  5. Modifiers won’t export to Unreal Engine and need to be applied before or at export

  6. Game ready rigs should be controlled with constraints and not parenting. In addition, the character’s mesh has to be connected to the deform rig via vertex groups only and not parenting

Rigging Preparations

Before starting with these preparation and clean up steps, make sure to create a backup of the Blender file. Also, try to create your future projects with these steps in mind:

  • Feet right above world center
  • Humanoid characters in A-pose (not T-pose)
  • Tails on characters or creatures, if present, should be straightened
  • Clothing or accessories that hang from the body should be in a gravity friendly state in the rest pose
  • Humanoid character matching proportions of UE5 mannequin (things like arm length and head size).
  • Character at realistic unit scale
  • Facing front
  • Units, dimensions & transforms correct (origins/ pivot points centered)
  • All origins should be at the world orogin if possible
  • Applying modifiers
  • Deleting vertex groups, relations & parenting

his step is only needed if you plan on retargeting and want the best, most compatibility with stock Unreal Engine or Unreal marketplace poses and animations

Meta-Rig

As we’ll be using rigify to generate a control-rig, the meta-rig should be compatible with rigify. The best way of doing this is by starting with rigify’s “Human (Meta-Rig)” (Add > Armature) and then adding to that the bones that one still needs for the character. There’s nothing special about this pre-made meta-rig, and one can easily replicate it with rigify’s meta-rig building blocks, but sticking with the pre-built rig will reduce the chance of errors when generating the game-rig.

Some examples of things one might require extra bones for, are hair and body physics, extra body parts like more than two arms, a tail, an extra set of ears or clothing parts that require bones.

All of that can be added as long as one isn’t adding in new bones into pre-existing bone chains and doesn’t delete any bones. The only exception to that is the face, if you don’t need to animate the character’s face, then delete all the face bones from the met-arig, including the bone called “face” hiding inside the “spine.006” bone.

For a better understanding on how to customize the meta-rig, or create your own from scratch with the meta-rig building blocks, I recommend watching this video series by CG Dive.

Before placing the bones, make sure to enable X-Axis mirror as well as In Front (Outliner > Data > Viewport Display). When placing the bones, use Snap to Face (Shift + Tab) to quickly place bones where they roughly should be.

Bone Placement

I won’t say too much more in regard to bone placements as the text above is quite comprehensive, but one thing to take into consideration, is that a lot of people will quite heavily rely on automatic weights. For anyone that uses automatic weights, placing the spine in the center of the body is essential, so the weighting algorithm can evenly place the weights. But if one anyway weight paints by hand, which one should, then that shouldn’t be a reason to place the spine in the center of the body. That doesn’t mean however that there aren’t other benefits of placing the spine in the center of the body as bandages mentioned above.

Looking at reference of skeletons or people in poses can help with placing the bones.

Supporting Bones

The most bare bone meta-rig that would be able to move everything would be structured like this:

  • Two arm bones
  • Two leg bones
  • A couple of spine bones
  • Some neck bones
  • A head bone
  • A hand bone
  • A bone for every finger joint
  • Two foot bones (one for the main part of the foot and one for the toes)

This meta-rig would allow for everything to move normally, but it wouldn’t look very good. The thing that’s missing are supporting bones. Examples of supporting bones are:

  • Clavicle bone
  • Scapula bone (rare, and hard to implement but important if back deformation is key)
  • Arm twist bones (A replacement for the twin bone twist system (Ulna & Radius) in our body. Even though the upper arm bone (Humerus) doesn’t have this, it doesn’t hurt to also give it the twist bones)
  • Palm bones (helps with poses like fists and spreading out all the fingers)
  • Pelvic bone (makes the leg bone have less influence of the hip area)
  • Extra hip area support bone
  • Breast bone (only for females, to get a realist breast movement)
  • But bone (not to common but can make sense)

Note that some of these aren’t that important and are used to improve the result of automatic weight algorithms.

Of those, the rigify meta-rig includes the clavicle, arm twist, palm, pelvic and breast bones. The arm twist bones won’t be visible at first in the meta-rig, but will appear in the generated control-rig (This behavior can be modified or disabled. Select the upper arm bone in pose mode and go to Outliner > Bone > Rigify Type. Setting Limb Segments to 1 will disable arm twist.)

Control-Rig

ToDo: Finish the control-rig section

ToAdd: A great benefit of having a script like rigify generate the control-rig, is that one can re-generate it on a whim without having the set-up things again, as all the set-up happens in the meta-rig. Losing the control-rig basically doesn’t matter as all the weights are stored in the vertex groups of the character’s objects and the poses and animations are key framed in the action editor. Only the current un-keyed pose would be lost. This is also why one should never delete the meta-rig after the control-rig has been generated as one never knows when one will need the blueprint for the control-rig again.

ToAdd: Quickly talk about WGTS collection. (The WGTS_rig collection can also be disabled)

ToAdd: Cover possible control-rig generation errors Bone spine disjoint: Some bone heads and tails have to overlap, so they were probably moved away from each other when aligning the rig. Make them overlap again by using Snap to Cursor. This error appears when specific bone heads and tails aren’t overlapping anymore. To find which bones are the culprit, look at the default rigify meta-rig and see if there are any perfectly overlapping bones that aren’t overlapping anymore on your rig. To make them overlap, use Snap to Cursor. If there is some specific reason why you don’t want to have the bones overlap, then you can tell rigify that those bones aren’t supposed to overlap. ORG-nose not found: Not all face bones were deleted. Armature transforms incorrect: Apply transforms before generating rig.

Weight Painting

Some Theory

Weight painting also referred to as skinning, is the process of binding the mesh to the control-rig / game-rig, or more specifically, the deform bones.

If you’re totally new to weight painting, then I recommend watching any or all of these videos.

Before we get into the workflow, let’s take a look at how weights work in general and how Blender handles them.

Weights represent the control a bone has over any given vertex of a mesh, the more weight, the more control a bone has. Blender stores weights in vertex groups. When weight painting a character, every bone will have a matching vertex group that shares the name of the respective bone. While weight painting a bone, if the entire mesh is pink instead of the usual weight paint color, then that means that there is no vertex group with a name matching the bone. You’ll see this whenever you select any part of the control-rig, as it will obviously not have associated vertex groups.

Posing in general relies on the concept, that every vertex’s weight on a mesh is controlled up to 100% by bones and no more. This means that two bones can’t both control 80% of a vertex’s weight, one of the bones could however control 30% of the weight while the other one controls 70%. This single concept is quite literally all there is to posing a 3D character. In Blender, a weight control of 0% (0) is visualized with the color blue and a control of 100% (1) with red. Per default, Blender won’t be very strict when enforcing the rule of every vertex can only be controlled up to a 100%, as one is able to give many bones 100% control over a vertex’s weight. The reason why Blender allows this, is because it will interpret three bones 100% control over a vertex’s weight, as three bones that control only 33.33% of it. In addition to that, if a vertex’s weight is in total only controlled by 40%, then Blender will interpret the control as 100%. This takes away the user’s responsibility of making sure vertex weights don’t surpass 100%. When the rigged character is then exported from Blender, Blender will modify all the weights, so they conform with the 100% rule, which ensures that this way of handling weights is compatible with other software.

There is one issue with this approach, however, if one wants to return the full control over an area of the mesh to a bone, then one has to first go through every other vertex group and remove that area’s weight. This would without a doubt drive anyone insane, and is where a feature called Auto Normalize comes in. Auto normalize will make it impossible for any vertex’s weight to bypass 100%. This is achieved by evenly reducing or “stealing” the weights from other vertex groups as soon as the sum suprasses 100%.

Binding Mesh to Rig

There’s one last step before one can start weight painting and that’s binding the character mesh to the control-rig or game-rig. In Blender this is done through the Set Parent To menu (Ctrl + P). In this menu, there are three relevant choices: With Empty Groups, With Envelope Weights and With Automatic Weights. All of them do three things:

  • Parents all selected character objects to the rig
  • Creates one vertex group for every bone on every selected object with the respective name of the bone
  • Adds an Armature modifier to all selected objects and sets the selected rig in the modifier options

In addition, the With Envelope Weights and With Automatic Weights options will do some automatic weight painting for you based on two different algorithms. With Empty Groups will as the name implies not add any weight paintig to the vertex groups.

I personally recommend using With Empty Groups as it will better teach you how to weight paint and will actually speed the specific workflow we’ll be using. If you however just want a quick and dirty result, then use the With Automatic Weights algorithm. That algorithm will quite often result in a “Bone Heat Weighting” error message. If that happens, then one can use the Voxel Heat Diffuse Skinning add-on or it’s free version which improve and add to Blender’s weight generation algorithms.

If when using automatic weights, you don’t want to give everything weights, then temporarily turn off deform for those bones (Alt + W) or (Properties > Bone > Deform). (Ctrl + Shift + W exclusively enables instead of toggles and can be useful in some situations).

What Bones to Weight Paint

As mentioned above one should only ever weight paint deform bones. The deform bones are all in the bone collection called “DEF” which is hidden by default and needs to be un-hidden (Outliner > Data > Bone Collection). (In pre 4.0 Blender bone collections were called bone layers and weren’t nameable. The deform bones from rigify rigs were on layer 30)

The deform bones will be hidden at first and need to be un-hidden. They are all on the layer called “DEF” (Outliner > Data > Bone Collection)

Weight Painting Tools, Options & Tips

This is a relatively long section, but not being aware of these things will make your weight painting experience miserable, so at the very least skim through left column.

Bones and Pose

NameDescription
Live Deformation FeedbackTo get live feedback on how the weight painting effects the mesh, use the weight paint pose hybrid mode. To enter it, select the rig followed by Shift selecting the mesh and enter weight paint mode.
Reset PoseTo reset the posed bones one usually goes to Pose > Clear Transform > All, but as that is not available in weight paint mode, use the Search menu (F3 / Space) and search for “Clear Transform All” or even better, add that option to the Quick Favorite menu.
Merging ObjectsIf a character’s low is made up of many objects, then it can make sense to merge as many as possible before weight painting, to reduce the amount of objects that need to be weight painted. Merging too much together can sometimes make it harder to paint, but that can mostly be fixed by using vertex selection limits and the X-Ray Weight Paint add-on. Eyes for example should probably be their own object and not merged into the rest of the character.
IK Helper for Game Rig PaintingIf you’re weight painting a game-rig instead of a control-rig, then to help with weight painting it can be useful to add a quick IK setup for posing the bones, just make sure not to change the bone hierarchy.
Switching Between BonesSwitching between bones can be done in a couple of ways. One can Ctrl + Shift click them (just Ctrl in pre 4.0 Blender), or select the corresponding vertex group through either the Vertex Groups menu under the Object Data tab, or the vertex group dropdown list, at the top of the viewport.
Bone Searching and FilteringThe Vertex Group Object Data tab also has a filter field collapsed under the triangle icon, which can be helpful for filtering by terms like “arm” or “r”.
Auto Locking Opposite Bones (L / R)There is currently no way of automatically locking and unlocking the opposite bone at the same time.

Tools

NameDescription
Weight Painting Multiple Objects at OnceAs of version 4.2, Blender only allows for one object to be weight painted at a time.
Basic Weight Painting ControlsLMB adds weight, while Ctrl removes it. This behavior depends on the Blend Mode (Tool > Brush Settings) which should mostly be kept at mix, as well as the Weight and Srength values.
Smoothing WeightsSmoothing weights is an integral part of weight painting. One can either evenly smooth the entire vertex group with the Smooth button (Weights > Smooth). Or use the Blur tool for more targeted smoothing (holding Shift while painting will temporally switch to the Blur tool). Smooth is however as of version 4.2 still broken and will not take Auto Normalize into consideration. Until this is fixed you should under no circumstance use smooth. As smooth is mostly better and quicker than blur, this is hopefully fixed soon.
Other ToolsOther useful tools like Sample Weight and Gradient can be found in the toolbar (T) (The gradient tool is as of version 4.2 still broken the same way smooth is, and won’t take Auto Normalize into consideration).
Auto NormalizeAn essential option to enable is Auto Normalize (Tool > Options > Auto Normalize). The full explanation on it is at the start of the weight painting section, but basically to recap, this option makes it impossible for more than one bone to fully control one vertex. It achieves this by automatically while one is painting, stealing and adding weights to surrounding bones to never surpass the 100% weight control.
Auto Normalize ButtonThe Normalize All button (Weights) will force all vertices to only be controlled up to 100%. This can be helpful, but can also mess up weight paint. Optimally, one would never want to get into the situation where this option is needed, by using Auto Normalize from the start and not painting with the Armature off.
Mirroring Weight PaintMake sure your weight painting is being mirrored, by enabling Mirror Vertex Groups as well a setting the mirror axis to X (Tool > Symmetry). This feature works by looking at the name of the vertex groups and matching “l” (left) and “r” (right) vertex groups. If you forgot to enable mirroring, then there are ways to mirror the entire model’s weight paint or only selected weight paint groups later on, a video on that here.
Limiting Weight Paint To Areas (Masking)To limit weight painting to an area, enter edit mode, select the vertices and back in weight paint mode switch to vertex or face selection mode, which will lock all vertices from being painted that aren’t selected in edit mode.
Paint Through MeshTo paint through the mesh, both Front Face Only (Properties > Tool > Advanced) needs to be disabled and the Falloff Shape should be set to Projected (Properties > Tool > Falloff). There’s an add-on called X-Ray Weight Paint which does this automatically and thus makes switching between normal and paint through weight paint mode easier. Just be aware that it can be buggy sometimes (Make sure to disable paint through as soon as it’s not needed anymore, as it can easily mess up your work).
Painting FalloffBased on the situation and one’s personal preference, it can also make sense to disable or enable Front Face Only painting (Brush Settings > Advanced > Front Face Only). I like to keep it on as the brush falloff is more natural with it on.
Assing Automatic from BonesToDo
CleanClean (Weights) will remove stray weights.

Visual

NameDescription
Display Zero Weights as BlackPer default, one will see the weight paint ranging from blue (0) to red (1). Vertices that don’t yet have a weighting for that bone will be displayed as blue, which is simply misleading. Setting Zero Weights to Active (Weight Paint Overlay) will help identify many issues directly when they occur, instead of when posing. Having this is especially important when using Auto Normalize tools.
WireframeI personally can’t weight paint without wireframe on, it tremendously helps gauge how the deformations will look like and if any wacky things are going on. Keeping it on will also help build an understanding of how one can improve on the retopology of future characters (Overlays > Geometry).
Utilizing Multiple ViewportsHave two viewports both focused on the left and right side of the character and pose one side of the character. Then switch between the viewport with the relaxed and posed version while weight painting depending on the situation.
Better Overview of ResultsTo nicely see the weight paint, one should be in the Solid Viewport Shading mode with color set to single with white, or random. Changing the bone type to stick can also make things more readable (Data > Viewport Display > Display As). It’s also good to occasionally disable Show Overlays, to get a sense of how the mesh deformation actually looks like (maybe also have a dedicated viewport for this).
Showing Weights in Edit ModeThe weight of the currently selected vertex group can be shown in edit mode by enabling Vertex Group Weights (Mesh Edit Mode Overlays).
Viewing and Tweaking Single Vertex WeightsEnter Vertex Selection mode while weight painting, Alt select a vertex and view its weight painting in the right sidebar (N).
Bone Locking VisualizationLocked bones are red while unlocked ones are blue.
Pink Weight PaintPink weight paint signalizes, that the current bone doesn’t have any associated vertex group. Proceeding to paint will create a vertex group (this is mostly undesired).
Bone NamesEnabling bone names can be helpful (Outliner > Data > Viewport Display) (If the names don’t appear beside the bones, then enable Text Info under the Overlay options)
Bone AxesToDo: Explain why bone axes visuals are used. (Outliner > Data > Viewport Display)

Avoiding & Fixing Weight Painting Mistakes

It’s important to be aware that Auto Normalize can be inconsistent and buggy at times, it will seemingly randomly paint on completely other parts of the model. A reliable way of almost fully countering this, is by using the lock workflow, more on that workflow later. It’s still possible though for the other side of the model to get messed up, as one has to unlock both the left and right bone pairs when painting.

Another important thing to know about Auto Normalize, is that it will completely stop working if the Armature modifier is disabled. This is mostly not wanted as weights will start going over 100%. But whenever Auto Normalize isn’t doing what you want it to, because it’s being buggy, then it can make sense to quickly disable the Armature modifier, fix the mistake and enable it again.

Painting on the other side by accident can also sometimes be your doing. You’ll mostly notice this happened when things start moving that shouldn’t be moving. To quickly fix it, increase the brush size and make one big stroke over that side with X-Ray Weight Paint on.

The Workflow

My workflow is based on Yami’s. Here’s a video of him showing it in action:

I personally find this is to be the only viable workflow for weight painting in Blender.

In the video he only weights paints a simple meta-rig, but when weight painting a proper control-rig, instead of starting with the clavicle, one should start with the uppermost arm bone. Other than that, one simply works ones way down every bone chain of the rig. For the hand, one has the hand bone and one of the palm bones unlocked. Then one slowly makes ones way down the finger and repeats it again for the next palm bone, also unlocking the hand bone again. This is the most tedious weight painting area but a necessary evil.

Here’s a less strict version of the workflow which I also quite like. It doesn’t rely on locking bone groups, which makes it more flexible and fast.

Refining the Deformations

Look at reference art of nude people in poses or you own body and look for things like where creases occur or how skin is pulled when limbs are bent. For example try putting your finger right above where your upper and lower arm bones meet (Humerus & Ulna) and watch how your finger moves when you bend your arm. Or raise your entire arm and see how the skin on you chest is also pulled up as well. 3D rigs are made to emulate our own skeleton and the whole weight painting system basically works the same way on our own body.

The best way however to learn how weight groups should look is by looking at rigged and weight painted charcaters from other artist that have more experience with it. There are plenty of free models available online, but for paid options I recommend buying one of Ryan Reos’s or Dzung Phung Dinh’s recent models. Both of them are masters of deformation. Rush Zilla is also very good at that, but I’m not sure if he makes his models available online.

ToDo: Talk about areas that need extra fixes to nicely deform, like knees and elbows.

Switching out the Rig

Even after the character’s weight painting is complete, one can still change out the rig without losing any weight painting work. This works as long as the new rig’s bones have the same names. To do this, all links between the rig and the character’s model need to be removed.

This is done by un-parenting all the character’s objects from the rig via Clear Parent (Alt + P), followed by removing the armature from all the objects, which is something that is hard in vanilla Blender, but very easy with the BatchOPS add-on.

Then instead of following the normal binding process, which would mess with the weight painting in the vertex groups, one does it manually. First select all the character’s objects and parent them to the rig (Ctrl + P). Then all the objects need an armature modifier which points to the rig. To do this, one first has to make sure that the built-in Copy Attribute Menu add-on is enabled. Then one simply sets up one armature modifier on any of the objects, selects the rest of the objects and in the Copy Attributes menu (Ctrl + C) selects Copy Selected Modifiers.

(If the prior rig is deleted then in theory none of these steps need to be done, as the new parenting would overwrite the old parenting. And the old armature modifier would stay, but would reference no rig and thus do nothing. But this isn’t very clean and possibly prone to unexpected outcomes.)

Now you can re-generate the rigify control-rig with the new meta-rig, and everything should work.

If you also want to reset the weight painting and delete all vertex groups. Then you’ll need to use either the BatchOPS add-on or find a script online like this one, as Blender currently isn’t able to bulk delete vertex groups from multiple objects.

Game-Rig

Once the control-rig and weight painting are done, one can finally generate the game-rig.

If you haven’t read through the what makes game readyrigs unique section, then do that first.

CG Dive has a video series called bridging the gap, which I recommend watching for a full encompassing understanding, of the possible hurdles there are and what issues to watch out for.

I’ll continue with the assumption that the character is meant to be used in Unreal Engine 5.x. It’s important not to be using UE4 as UE5 changed quite a lot in regard to rigs and animations.

WIP: The game rig section is still a work in progress, as I’m still figuring out the most optimal and comfortable workflow.

Additional Helpfull Videos

These channels produce a lot of great content focused on rigging: