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3D modeling tips

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Clean geometry

Each polygon needs to have a purpose and help sell the believability of the Environment. If edge flow creates confusing shadows or hard-to-understand shapes, you can simplify. If a mesh won't be seen up close and has dense polygons, you can reduce its complexity.

A clean and easy-to-understand silhouette goes a long way towards amplifying an environment or prop. A properly optimized mesh goes a long way towards driving polish and enhancing the user's experience.

Unseen faces

Make sure you delete faces the user will never see. Not only will this save on polycount and increase performance, it also has a huge benefit when creating optimized light map UVs.

VR users

VR users can 'escape' collision boundaries by physically moving the headset, with approximately up to two meters of wiggle room.

Plan for this and don't delete faces as aggressively when they're close to the collision boundaries.

A picture containing text, screenshot Description automatically generated

Aliasing

When modeling and designing, avoid straight lines and aliasing-producing materials. This will save technical overhead later and create a better experience for users.

Use matte, smooth, and larger shapes when possible. Avoid bevels, hard edges, and metallic materials.

Consider the distance a user could be from an object and the lighting of your Environments. Thin objects render as straight lines and metallic objects produce specular artifacts when lit. It's best to avoid these outcomes, when possible, with careful modelling.

Resources for minimizing aliasing in levels & materials

Level design: Advanced VR Graphics Techniques (arm.com)

Banding: Advanced VR Graphics Techniques (arm.com)

Minimizing polycount for props

Increase performance of your final scene by minimizing the polycount of your props before exporting them. This will reduce the resource cost to render objects and maximize performance in your final scene.

Resources for minimizing polycount

Maya polycount reduction how to: HOW TO REDUCE POLYCOUNT IN MAYA - YouTube

Maya polygon modeling tips: Maya Help: Polygon modeling preferences and tips (autodesk.com)

Materials

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Name each material in your .fbxfile to closely match its corresponding material inside Unity. Avoid exporting default material names.

Stairs

To optimize performance and to prevent visual artifacts in both camera and character, we recommend representing stair collision geometry as a sloped plane without modifying render geometry.

The character controller is represented by a capsule with a small radius which does allow it to effectively climb up stepped geometry. However, this approach can cause jittering0F[^1] in both the camera and character movement.

Model textures

Using flat colors and a clean light bake instead of custom textures is a very efficient and performant route to take for prop textures.

These props don't have custom textures, but instead rely on the URP/Baked Lit shader's Base Map color value and a clean light bake.

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Not using textures also eliminates texture artifacts like pixelization and aliasing, which is a big boost to VR immersion.

When a custom texture is used, like on these purple plants, green leaves, and the red leaves of the tree, keeping the detail simple and clean goes a long way towards hiding the textures' low resolution.

An image of an environment with trees, rocks, and structure.

Tiling textures should be authored at 3x3 meter scale.

An image of the Zen meeting space

All tiling textures should be authored left to right.

Correct:

An image of a brick surface showing horizontal patterns of brick layout

Incorrect:

An image of a brick surface showing vertical patterns of brick layout

Unity model importer

Utilizing the Unity Importer for material management not only speeds up iteration time, it also has a positive impact on performance. As of Spring 2022, when the Importer lists the On Demand Remap slot as 'None (Material)', Unity embeds the default URP/Lit material into the asset.

Even one material set to 'None (Material)' has a performance cost.

A screen shot of the Unity Environment Exterior Import settings dialog

Ensure that all slots have corresponding Unity materials loaded in, as shown below.

A screen shot of the Inspector - Environment_Exterior import settings dialog in Unity

Unity shaders

  • Universal Render Pipeline overview | Universal RP | 12.1.4 (unity3d.com)

  • Baked Lit Shader | Universal RP | 12.1.4 (unity3d.com)

  • Complex Lit Shader | Universal RP | 12.1.4 (unity3d.com)

Shaders

Microsoft Mesh utilizes the URP renderer. Unity has multiple built-in URP shaders available to use.

For Android-focused projects, we only use the following:

URP/BakedLit

URP/Unlit

For PC / High-end focused projects, we recommend that you use the following:

URP/ComplexLit (if advanced materials are needed)

Resources for Unity shaders

Complex Lit Shader: Complex Lit Shader | Universal RP | 10.2.2 (unity3d.com)

Shader graph

Unity Shader Graph is okay to use; however, performance could be negatively impacted if the custom shader isn't properly optimized.

For Android projects: we highly recommend that you stick to ~30 math operations in vertex, ~120 math operations in fragment, and ~2 texture look ups.

Shader Features

Most shader and renderer features are available to every platform, but some platforms disable features for performance considerations.

Android PC
_CameraDepthTexture ❌ ❌
_CameraColorTexture ❌ ❌
HDR ❌ ❌
MSAA 2x 2x
Reflection Probe Blending ❌ ✔
Post Processing ❌ ❌

When unsure if a setting is enabled or disabled for a platform you are developing for, reference the URP assets contained within the Mesh toolkit Uploader's URP folder:

A screenshot of the Inspector - Environment_Exterior Import Settings dialog

Note: Altering render pipeline settings or adding renderers isn't supported.