Popul8 Express automates character creation, streamlines asset fitting, and generates infinite variations instantly. All you need is a single 3D base character that aligns with your technical and artistic requirements—Popul8 handles the rest. It creates diverse head and body variations, automatically fits your existing asset library to every character, and generates rich, game-ready crowds that you can seamlessly import into your engine of choice.

Your specifications. Your topology. Your characters. Your assets.

This guide will walk you through using Popul8 Express to revolutionize your character creation pipeline.

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Concepts

Popul8 Express relies on six key concepts:

Template

A Template is a 3D model of a character that defines all the technical specifications required for characters generated by Popul8 (e.g., topology, rig, textures, art style, etc.).

Shape

A Shape is a new character that adheres to the Template’s technical specifications (e.g., same topology, same rig, same number of materials) but features unique head or body variations.

Deformable

A Deformable is any asset that complements a character, such as garments, grooms, accessories, etc.

Animation

An Animation is an instance of the Template's rig with a key-framed sequence defining a specific motion or action.

Crowd

A Crowd is a collection of characters that adhere to the Template’s technical specifications. These characters feature variations in Shape and Deformables, and are generated based on predefined rules.

Crowd Rule

A Crowd Rule controls how different Shapes and Deformables are distributed within a Crowd, following specific ratios. It allows you fine-grained control over your Crowds.

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Project setup

This section explains how to set up your project in Popul8 Express from scratch. If you're using the DemoExpress project included with the Popul8 Express trial, you can skip these steps— we've already set them up for you . However, you can use this guide when testing with your own assets.

Creation

When creating a project from scratch, the first step is to define a name and choose a location on your disk. For a smoother workflow, it's best to store your project in a location that also contains the assets you plan to import.

Importing assets

Once your project is initialized, you can begin importing your assets. You have two options:

• Import files individually (Right-click → Import → File).
• Import one or multiple folders (Right-click → Import → Folder).

All imported assets will appear under the Imported Assets section in the Project tab.

Supported file formats:

• 3D Models: FBX
• Textures: PNG, JPG

Sorting assets

In the previous step, you may have imported various asset types, such as Templates, Shapes, Deformables, and Animations. To ensure Popul8 correctly processes each asset and unlocks its full potential, you need to specify its type.

How to assign asset types:

1. Browse the list of imported assets.
2. Right-click an asset and select Convert To → [Desired Asset Type].
   1. Available types: Template, Deformable Of, Shape Of, Animation Of.

Since Deformables, Shapes, and Animations must be linked to a Template, we recommend setting up your Templates first before assigning other asset types.

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Any Deformable linked to a Template will automatically be fitted to all Shapes associated with that Template.

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Any Animation linked to a Template will automatically be retargeted to all Shapes associated with that Template.

Refining materials

You can refine the materials associated with any Template, Shape, or Deformable either before or after assigning its type. The material definition supports albedo, normal maps, and mask maps. Materials linked to a model are specified as its children, allowing you to select and assign the appropriate textures.

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Key features

Shape Editor

The Shape Editor is a tool for creating head and body variations based on a Template. These variations can be generated using either:

• A default deformation rig, which can be retargeted to your own Template (see how here).
• A custom deformation rig.

The DemoExpress project uses the default rig.

How to use the Shape Editor

1. InDemoExpress, under the Male Template, select Shape Editor and click Launch.

   

2. Once the editor opens, enter one of the 17 body regions to start modifying the head and body shape.

3. Adjust the sliders to achieve the desired look.

   

Alternately, to generate random variations, click the Randomize button in the top-left corner. Once you’re happy with your creation, click Save and Exit on the top right corner.

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Your new Shape will automatically appear under its corresponding Template, with all supported Deformables automatically fitted to it!

For advanced usage of the Shape Editor, check the official documentation.

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Asset Fitting

The Default Asset Fitter

When linking Deformables to a Template, we automatically fit them to all Shapes associated with that Template using default settings. These settings are stored in an object called Default Asset Fitter, which is automatically initialized with every project. You can find it at the bottom of the Project tab.

From Template to Shape

To view how the automatically fitted Deformables look, simply drag the intended Shape into the outliner, followed by the Deformable(s) you want to inspect. Below, we showcase how the Deformables Sports_Shorts_Color1, Sports_Shirt_Color1, Casual_Shoes, and BaseballHat_01_Color1 look on three different Shapes in the DemoExpress project: the Template (first image), the Heavy Shape (second image), and the Goblin Shape (third image).

How to use a custom Asset Fitter

When fitting a Deformable to a Shape with significantly different body proportions from the Template, the default fitting method (Fast method) may not yield the best results. In such cases, you can create a custom Asset Fitter, link it to the Deformable, and adjust the settings for better results. Here’s how:

1. Create a custom Asset Fitter – Right-click on the Deformable and select Create → Asset Fitter. This will add a new Asset Fitter object under the Deformable.

2. Link the Asset Fitter – Select the Deformable, then drag the new Asset Fitter object into the Asset Fitter slot. This ensures the fitting process uses your custom object instead of the default one.

   

3. Customize the settings – Open the new Asset Fitter object and adjust the parameters. Switching the Deformer from Fast to Accurate can significantly improve the fitting.

   

In the DemoExpress project you can find a custom Asset Fitter in the Goblin Shape, on the Deformable Sports_Shorts_Color1. Switching to the Accurate Deformer instead of the Fast one greatly enhances the fit!

Even though the Accurate fitting method generally performs well—even when adapting Deformables to Shapes that differ significantly from the Template—minor intersections with the body may still occur. You can mitigate these by adjusting the Expansion slider on the Asset Fitter, which loosens the fit of the Deformable. Alternatively, you can manually fix each intersection—we’ll show you how in the Handling Intersections section.

Fitting with rigidity

When fitting a Deformable to a Shape, certain regions—such as metallic pieces, armatures, buttons, buckles, or certain patterns—should remain stiff. However, they may deform unexpectedly during the fitting process. To preserve their structure, you can apply stiff regions using a custom Asset Fitter. Here’s how:

1. Import stiff region masks – Use binary masks painted in the Deformable's UV space, where stiff regions are represented in white and flexible regions in black.

2. Define stiff regions – In the Asset Fitter, click the "+" button to add a new stiff region, then drag the region mask to the UV Masks slot. Adjust parameters like Stiffness Type and Bleeding as needed.

   

3. Apply changes – Click Apply Changes to update the Deformable’s fitting and preserve the intended structure.

You can see an example in DemoExpress, where a custom Asset Fitter with stiffness regions is applied to the Goblin Shape on the BaseballHat_01_Color1 Deformable.

For more information about the usage of the Asset Fitter, check the official documentation.

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Handling Intersections

Intersection Solver

The Intersection Solver is a tool that can be linked to any Deformable to detect and solve intersections with the Template or Shape it is fitted to.

How to use the Intersection Solver

1. Create the Intersection Solver – Right-click on the Deformable and select Create → Intersection Solver.
2. Detect intersections – Click Verify to detect any intersections between the Deformable and Template/ Shape.
3. Fix intersections – Browse the list of detected intersections and fix them individually, or apply all suggested fixes at once by clicking Fix All.
4. Finalize the adjustments – Either run Verify again to check for remaining intersections or save the updated Deformable by clicking Apply Changes.

You can see an example in DemoExpress, where an Intersection Solver is applied to the Goblin Shape on the Sport_Shirt_Color2 Deformable. The solver is already in place, but if you want to experience the process yourself, simply press Revert to undo the applied fixes. Then, follow steps 2 through 4 to detect and resolve intersections on your own!

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Fixing intersections between a Template and a Deformable will automatically trigger fitting updates on the Shapes. As a result, the Deformable’s fitting will improve across all Shapes thanks to the intersection fixes on the Template!

For more information about the Intersection Solver, check the official documentation.

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Create Crowds

A Crowd is a collection of characters that follow the Template’s technical requirements but feature variations in head and body shape, along with randomized Deformables assigned to each Crowd Character. You can create rules to control how these elements influence your Crowd's appearance.

How to create a Crowd

1. Create a Crowd Object
   Right-click anywhere and select Create → Crowd. This will generate a new Crowd object under the Crowds section in the Project tab. You can now rename your Crowd.

   

2. Instantiate Characters on your Crowd

   1. A Crowd can include Characters from multiple Templates. To define how many Characters each Template should contribute:

      1. Add a new entry under Characters Per Template.
      2. Enter the desired number of characters in the Character Count slot.
      3. Drag the corresponding Template into the Asset Object slot.

   2. Click Apply Character Count to generate the Characters.

      

      
      

Your Crowd will now contain the correct number of Characters, all matching their respective Templates. From here, you can define rules to introduce variations and make your Crowd come to life!

Introducing Crowd Rules - rules for facial variation

You may want to introduce facial variations in your Crowd to enhance diversity. You can achieve this by blending between the Shapes associated with the Template of each Crowd Character.

Popul8’s blending method seamlessly combines the geometry and textures of your selected Shapes with varying weights, generating unique and natural-looking facial variations across your Crowd. You can use Shapes that you previously designed in the Shape Editor or Shapes designed in an external software and imported into Popul8.

In the DemoExpress project, you'll find 12 externally designed Shapes assigned to the Male Template ( from African_1 to West_Asian3). These Shapes feature distinct head shapes and different albedos for the head, body, and eyes. When using a Shape to generate facial variations in a Crowd, which is a special case, you must enable the Blend Textures and Is Facial Variation toggles for each Shape.

In the Crowd Rules section, you'll find a rule called RuleMixFaces, which defines how Shapes are blended within the Crowd to create facial variations. Here's how to create that rule:

1. Create a New Crowd Rule

   1. Right-click anywhere and select Create → Crowd Rule. This will instantiate a new Crowd Rule, which you can rename.

2. Set Up the Rule for Facial Variations

   1. In the Crowd Rule settings, specify that you're creating facial variations by setting:

      1. Shape Blend Type to EXTREME (the optimal blend type for this purpose, but the DEFAULT mode also works).

      2. Shape Blend Number to 3, meaning each Character will blend between three different Shapes with varying weights.

         

3. Assign Shapes to the Rule

   1. Drag the previously labeled facial variation Shapes into the Properties section.

      

Now, you’re ready to use this rule in a Crowd! To apply it:

• Open your Crowd object.
• Drag the newly created Crowd Rule into the Crowd Rule Editor Graph.
• Link it to the Crowd, as shown below.

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Any new rule linked in the Crowd Rule Editor will automatically update your Crowd!

You can now drag your Crowd to the Outliner and instantly see all the variations you've created!

Crowd rules for height and weight variation

You can also create rules to achieve variations in body weight and height in your Crowd! You can create simple rules like the ones shown below, where we use two Shapes to create height variation (the Tall and Short Shapes) and weight variation (the Thin and Heavy Shapes).

Setting the Shape Blend Type to DEFAULT and the Shape Blend Number to 1 will provide natural body variations in your Crowd.

You can see below the effect of linking these two rules on the Crowd Rule Editor.

Crowd rules for distribution of deformables

You can create rules to distribute Deformables across the Characters in your Crowd using the same procedure as the body height and weight rules.

You can design separate rules to distribute Deformables for different body areas, such as the legs, torso, feet, head, and more—the choice is yours!

The power of randomization

Not happy with how a Character looks? Want to tweak a specific feature—maybe make it a bit taller or adjust its proportions? Or perhaps the overall look of your Crowd isn’t quite right, and you’d like to try again. You can easily randomize either a specific Character from the Crowd or the entire Crowd with just a few clicks!

Tweaking traits of a Crowd Character

Randomize Crowd Character

Randomize a Crowd

Cross-Species Creations: Hybrid Crowds Unleashed

Why limit yourself to just head and body variations? Use the Crowd’s blending system as a creative playground to bring novel creations to life!

In DemoExpress, we created a hybrid Crowd by blending several human Shapes with a Goblin Shape to showcase the true power of blending. ⚠️ But be warned—with great power comes great responsibility! Be sure to fine-tune your Crowd rules to ensure the results match your expectations.

Optimizing Crowds with Culling

Rendering large Crowds can be computationally expensive, regardless of your engine choice. To reduce this load, you can cull parts of the body of your Crowd Characters that are occluded by the Deformables assigned to each Character. To do this, you’ll need to define cull masks for each mesh of the Character, for each Deformable. Here’s how:

1. Enter the intended Deformable under the Template.
2. Create an item in the Cull Data section.
3. Drag a cull mask to the Texture slot and assign the appropriate Template mesh to the Mesh slot.
4. Repeat steps 2 and 3 for all meshes that need to be culled.
5. Click Apply Changes when you're done.

Finally, enter a Crowd Character using the Deformable with the Cull Data applied to see the culling in action!

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Assigning cull masks to a Deformable under a Template will propagate the culling information to the fitted Deformable on the Shapes, and will automatically be used in your Crowd Characters!

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Culling is also an alternative to solve intersections between a Deformable and a Shape/ Template in a Crowd!

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Animation

You can preview an Animation at any time on a Template, Shape, Crowd Character, or even an entire Crowd! Simply expand the Animation dropdown menu and select the desired item to see it play on-screen.

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Export & Bridges

Once you're happy with the Crowds you designed you can export them in multiple ways:

• Bridge to:
  • Unity, following the steps described here.
  • Unreal Engine, following the steps described here.
• Export the Crowd files by right-clicking the Crowd and selecting Export as → Crowd.
• Export an individual Crowd Character by right-clicking the Character and selecting Export as → Single.

You can also export any Template, Shape, Deformable, and Animation by right-clicking and selecting Export as→ Model.