If you encounter issues with the appearance or performance of your model after upload, the steps below can help to resolve these problems.
Avoid using multiple materials whenever possible. In general, each material requires an individual "draw call". Draw calls are slow operations, and can impact performance heavily on slower systems like mobile devices.
To improve performance, try to use a single material.
Triplanar projection is currently not supported by Reviewer. Assets and meshes that are textured with triplanar projection need to have the triplanar data baked into regular UV based textures for use in Reviewer.
In general smaller texture sizes are better for performance. However, smaller texture sizes also mean less detail, so with textures, try to hit a balance between performance and quality. We recommend a resolution of 2048x2048 as this is usually enough to provide a high level of detail in areas that need it, while not resulting in a very large file size.
Triplanar projection is currently not supported by Reviewer. Assets and meshes that are textured with triplanar projection need to have the triplanar data baked into regular UV based textures for use in Reviewer.
Texel density refers to the number of texture pixels that appear over a given surface area on a mesh. Inconsistent texel density can mean that some areas of the mesh have a very high level of detail (many texture pixels), while other areas have a very low level of detail (few texture pixels).
In some cases using a different texel density is useful, such as ensuring that the label on a product appears crisp and detailed. But if texel density isn't managed, it can result in noticeable differences in quality on different parts of the same mesh. To avoid issues with texel density, we recommend starting with a consistent density across the mesh, and adjusting individual parts later if necessary.
Most 3D applications with the ability to modify UVs have a function to achieve a consistent texel density. In Blender, you can use "Average island scale". In Maya, the Layout function for UVs has options to manage texel density.
As with most 3D modelling, we recommend avoiding overlapping geometry that could cause z-fighting.
Additionally, try to avoid vertex nodes, where a single vertex connects more than 8 edges. This can cause pinching or other rendering artifacts, especially on curved surfaces.
For maximum performance, lower polygon counts are recommended.
While polygon counts are important for performance, optimizing mesh geometry usually doesn't have as much of an impact as optimizing textures and materials, unless your mesh has tens or hundreds of thousands of polygons.
Generally, it's a good idea to ensure that models are made up of quads or triangles before upload to Reviewer. During the optimization pass, Reviewer automatically triangulates the final optimized version of assets, and this step can result in unexpected geometry if many sided polygons (also known as n-gons) exist in the original geometry.
Reviewer maintains units of scale from uploaded files, regardless of file format. For example, if the mesh is authored in meters, any Reviewer-optimized files will also be in meters.
- GLB files only support meters as a unit of scale.
- USDz can support arbitrary units of scale, or even leave units of scale undefined. The USD file format defines a metersPerUnit property that Reviewer uses. If this property isn't set, Reviewer will default to centimeters.
- FBX supports a selection of units of scale. FBX defaults to centimeters, but Reviewer will use whichever unit of scale is configured for the file.
Some of your files may contain multiple meshes. For example, some assets may have both the product and the container that the product ships in. For these assets, we recommend combining the meshes in the file before uploading to Reviewer.
In Blender, you can achieve this with the Join operation. In Autodesk Maya, use the Combine operation.
In some cases, you may have full 3D scenes surrounding the product, such as a fully realised dining room for a dining table. Avoid using large scenes when possible to maximize performance. For AR and 3D use cases, we recommend only using the product itself. This improves performance, and also allows the users to focus on the product.
To ensure proper export of metallic and refraction properties to FBX, please use a newer version of the Standard Surface material. Our pipeline may not correctly interpret these properties if an older version of the Standard Surface material is used.
Transparency is necessary for many products, both for packaging, and the products themselves. If possible, try to avoid using meshes with multiple layers of transparency. For example, a crystal chandelier.
Multiple layers of transparency can cause performance issues, as the processor needs to determine the correct order of the transparent materials for each pixel. The more transparent layers on a given pixel, the more work the processor has to do.
For devices with slower processors, this can severely impact performance.
Animations and rigging are currently not supported by Reviewer. For best results, remove or freeze the pose of any rigged assets and strip out all animation and skeleton data before uploading to Reviewer. If animations are included in files, you may encounter unpredictable results.
While Reviewer has a file size upload limit of 500MB, it's strongly recommended to avoid uploading files anywhere near that size. Large file sizes mean longer loading time for users, and are more likely to crash the browser.
Large files are also generally more complex, and are an indicator that a file should be simplified before upload.
Reviewer recommends keeping optimized file sizes less than 3MB in general.
