Polygon count Guide

What is a polygon?

In 3D modeling, a polygon is a flat shape consisting of straight lines that are connected to form a closed chain or circuit. The most common polygons in 3D modeling are triangles (tris) and quadrilaterals (quads). The polygon count, or polycount, refers to the total number of these polygons in a 3D model.

While artists often model using quads for ease of manipulation, game engines typically convert these into triangles for rendering, as triangles are the simplest polygons and can represent any surface. Therefore, the triangle count is a crucial metric for assessing a model's complexity and its impact on performance.

For example:

• A cube made of quads = 6 faces

• A cube made of tris = 12 triangles

Why is Polycount important?

The polycount of a model directly influences both the visual fidelity and the performance of a game:vizent.co

• Performance: Higher polycounts require more computational power to render, which can affect frame rates, especially on devices with limited resources like mobile phones or VR headsets.

• Visual Quality: Higher polycounts allow for more detailed and smoother models, enhancing realism.3d-ace.com

• Optimisation: Balancing polycount is essential to ensure that models look good without overburdening the system. Techniques like Level of Detail (LOD) are employed to display lower-poly versions of models when they are farther from the camera.

A good artist balances detail vs efficiency, ensuring the model looks good but runs well in-game.

What to Consider When Setting Polygon Limits

When deciding on the polygon limits for models in your game, it’s important to strike a balance between visual quality and performance. Here are the key factors to consider:

1. Target Platform

The hardware capabilities of your target platform will directly influence how high or low your polygon budgets can be:

• Mobile: Devices have limited GPU/CPU power and memory. Polycounts must be kept low (e.g., <10,000 for characters).

• VR/AR: Requires high frame rates (often 90+ FPS), so optimisation is crucial.

• PC/Console: Can support higher polycounts, but performance still matters—especially with many models on screen.

• Next-Gen Consoles: Offer higher performance, allowing more complex models, but remember you're often rendering 4K and still need to optimise.

2. Art Style

Your game's visual style will affect how much detail is necessary:

• Stylised/Cartoony:

  • Often uses bold shapes and flat shading.

  • Lower polycounts are usually acceptable without noticeable loss of quality.

  • Example: Fortnite, Zelda: Breath of the Wild.

• Realistic:

  • Requires more detailed models for believable shapes and surfaces.

  • Higher polycounts are usually needed for faces, clothing, and props.

  • Example: Call of Duty, The Last of Us.

• Pixel Art/Low-Poly:

  • Sometimes intentionally minimalist.

  • Very low polycounts become part of the visual identity.

  • Example: Superhot, Untitled Goose Game.

3. Asset Purpose and Player Interaction

Not all assets need the same level of detail:

• Main characters and important props should have more polygons due to frequent close-ups.

• Background assets can be lower poly, especially if they're rarely viewed up close.

• UI-facing or interactive objects (e.g., weapons in FPS games) should maintain quality under scrutiny.

4. Camera Distance and View

• First-person games require high-detail hands/weapons.

• Third-person or isometric games can use lower-detail models due to camera distance.

• Assets far from the camera can have simplified LOD (Level of Detail) versions.
  
  

5. Scene Complexity and Asset Density

The total number of assets on screen affects how many polygons can be used per asset:

• A sparse scene may allow for higher-poly models.

• A dense urban level with many objects needs lower-poly models to keep performance up.

• Use LODs and culling systems (e.g., occlusion culling) to manage what's rendered.

6. Engine and Tools Capabilities

Different engines have different rendering strengths and limits:

• Unreal Engine 5 (with Nanite): Can handle massive polycounts, but not always necessary for all assets.

• Unity: Performs well with lower-to-mid polycounts and benefits from careful LOD management.

7. Game Genre

• Fighting games often need detailed characters due to close camera angles.

• Strategy games can use simpler models as the view is top-down and distant.

• Simulation games may involve large numbers of units on screen, polycount must be kept low for each.
  
  

By planning your polycount budget around these factors, you can ensure that your game looks great and runs smoothly across your target platforms. Always prototype and test early to see what works best in practice!