📦Modelling

This section covers the Modelling phase including proportions, poly counts and topology to name a few.

Proportions

To start your 3D project, first make sure you've set the correct unit measurements in your 3D software.

To get a better sense of size and scale, you can import a human model as a reference.

Adding a human model to reference asset sizing.

Polycount for Game Ready Assets

To achieve optimal performance in real-time rendering engines like Unity, focus on creating light geometry for your 3D models. This means using as few polygons as possible. Crafting low-poly models is a well-established practice that yields "game-ready assets." These assets are essential for preventing GPU and CPU overload, which can lead to application crashes.

The polycount guidelines for game-ready assets can vary based on the target platform, chosen devices, and hardware specifications. For a stable environment, adhere to the instructions below.

Note that these values are approximate and may change depending on the factors mentioned above:

Polygon Count by Asset Category

Small Assets: Polycount: 100 - 1,000 polys

Small objects like bottles, small furniture elements, framed pictures etc

Medium Assets: Polycount: 1,000 - 5,000 polys

Regular size objects like sofas, fountains, sculpture, intricate decoration etc Polycount: 1000 - 5000 polys.

Architecture and large objects: Polycount: 5,000 - 50,000 polys

Rooms, halls, internal /external architectural spaces

Foliage: Polycount: 300 - 3,000 polys

Flowers, bushes, grass mesh, plants, trees.

Avatars: Polycount: <15,000 polys

A fully functional character with clothes, hair and accessories .

Note on Camera/Occlusion Culling Camera culling, a built-in Unity feature, hides objects not visible to the main camera, offering a way to optimize performance. Level designers should take this feature into account when planning their levels. While it varies by scenario, a general guideline for target polycount is approximately <100,000 viewed polygons per frame.

An example of the same asset in both high poly (left) and low poly (right) versions.

Topology

Maintain clean and accurate topology in your 3D models to prevent mesh interpenetration and overlaps. Such errors can degrade engine performance and result in flickering surfaces. Low-poly design is generally more efficient with square shapes; for curved surfaces, the example polycounts may need to be doubled. Keep in mind that a model's polycount can vary based on its structural complexities. The provided values are guidelines and may require slight adjustments.

Pivot Positioning

Special attention should be given to pivot positioning. The pivot should generally be centered on the object and aligned with its lowest point. Exceptions can be made for specific cases; for example, a hanging object should have its pivot at the highest point.

⚠️ Always export objects with their position set to the origin coordinates: X:0, Y:0, Z:0.

An asset with the pivot point set correctly.