The 3D models you import into Twinmotion are composed of three-sided polygons known as triangles. 3D models with multiple parts and high triangle counts show a high level of detail but take more Graphics Processing Unit (GPU) resources and memory usage to render in the viewport. To optimize rendering and overall scene performance when working with highly-detailed 3D models, you can use the Nanite system or the Level of detail (LOD) feature.
The Nanite system and the LOD feature both manage the triangle count of objects based on distance between objects and the viewport camera, the amount of screen space objects take up in the viewport, and the requirements for optimal performance.
Objects that appear far away in the scene are also farther away from the camera and take up less screen space. When objects appear far away small details do not need to be displayed and the triangle count can be reduced, optimizing memory usage and performance.
As objects take up more screen space and get closer to the camera, the triangle count can be increased to show all the complexity and details of the objects.
Enabling Nanite or using generated LODs optimizes rendering while you work in Twinmotion but does not affect the quality and complexity of the objects in exported media. Objects render at 100% fidelity in exported media, whether or not you use Nanite or the LOD feature.
Nanite vs LODs
Nanite and the LOD feature both aim to optimize 3D models but they do it in a different way:
The Nanite system manages the triangle count of models dynamically down to the pixel. As objects move closer or farther away from the camera, the number of triangles is automatically reduced or increased in real time as they are divided up into clusters that Nanite can use.
Nanite triangles view mode. The LOD feature manages the triangle count of models in a static manner. As an object moves closer or farther away from the camera, one of a number of pregenerated LODs (based on a preset you select and that vary in triangle complexity) transition between each other.
Three generated LODs from the Normal preset applied to an object.
The optimization method you choose depends on the type of object or scene you are working with:
Nanite is more suitable for use in scenes that contain multiple instances of models that have extremely high triangle counts, including photogrammetry scans.
Dynamically regenerating the triangle count of 3D models has a cost and there may be performance degradation in some instances. If you do not see any performance benefits with Nanite, it may be advisable to use the LOD feature instead.
For more information on Nanite in Twinmotion, see Optimizing Geometry with Nanite.
The LOD feature is more suitable if a high-poly count 3D model appears only once in your scene.
For more information on automatic LOD generation, see Automatic LOD Generation.