How can you reduce polygon count for VR models?

1 Why reduce polygon count?

Reducing polygon count is not only a matter of improving VR performance, but also of enhancing VR user experience. High-polygon models can cause issues such as low frame rates, stuttering, lagging, overheating, and motion sickness. These issues can ruin the immersion and enjoyment of VR, and even deter users from using VR applications. On the other hand, low-polygon models can reduce these issues and make your VR application more accessible and user-friendly. Low-polygon models can also create a distinctive and stylized look for your VR application, depending on your artistic vision and goals.

2 How to measure polygon count?

Before you start reducing polygon count, you need to know how to measure it and what are the acceptable ranges for different VR platforms and devices. Polygon count is usually expressed in terms of triangles, since most 3D engines and graphics cards use triangles to render 3D models. You can check the triangle count of your models in your 3D modeling software, such as Blender, Maya, or 3ds Max. You can also use tools such as Unity or Unreal Engine to check the triangle count of your models in your VR scene. The optimal triangle count for VR models depends on various factors, such as the type and number of models, the level of detail, the lighting and shading, the texture resolution, and the target device and platform. However, as a general guideline, you can aim for around 50,000 to 100,000 triangles per model for high-end VR devices, such as Oculus Rift or HTC Vive, and around 10,000 to 20,000 triangles per model for mobile VR devices, such as Oculus Quest or Google Cardboard.

3 How to reduce polygon count manually?

One of the most common and effective ways to reduce polygon count is to manually edit your models in your 3D modeling software. This involves removing unnecessary or redundant polygons, simplifying or smoothing curved or irregular shapes, merging or splitting vertices or edges, and using modifiers or tools to optimize your geometry. For example, you can use the Decimate modifier in Blender, the ProOptimizer modifier in 3ds Max, or the Reduce tool in Maya to automatically reduce the number of polygons in your model, while preserving the shape and volume. You can also use the Remesh modifier in Blender, the Quadify Mesh modifier in 3ds Max, or the Quad Draw tool in Maya to create a more uniform and efficient mesh topology for your model. However, when using these methods, you should always check the results and make sure that your model does not lose too much detail, quality, or functionality.

4 How to reduce polygon count with LODs?

Another way to reduce polygon count is to use level of detail (LOD) models. LOD models are versions of your model with different levels of complexity and detail, depending on the distance from the camera or the user. For example, you can have a high-polygon model for close-up views, a medium-polygon model for medium-distance views, and a low-polygon model for far-away views. By switching between these models, you can save polygons and improve performance, while maintaining the illusion of detail and realism. You can create LOD models manually in your 3D modeling software, by following the same steps as above, or you can use tools such as Simplygon or InstaLOD to automatically generate LOD models for your model. You can also use tools such as Unity or Unreal Engine to set up and manage your LOD models in your VR scene.

5 How to reduce polygon count with baking?

A third way to reduce polygon count is to use baking. Baking is a process of transferring the information and details from a high-polygon model to a low-polygon model, using textures. For example, you can bake the normal map, the ambient occlusion map, or the displacement map from your high-polygon model to your low-polygon model, to create the impression of depth, shadows, and bumps, without using extra polygons. You can also bake the lighting and shading from your high-polygon model to your low-polygon model, to create a more realistic and consistent appearance, without using dynamic lighting or shadows. You can use tools such as Blender, Maya, or 3ds Max to bake your textures from your high-polygon model to your low-polygon model. You can also use tools such as Substance Painter or Quixel Mixer to create and edit your textures for your low-polygon model.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?