Rhino Asset Export

Geometry Workflow

Organization is important when exporting assets from Rhino or any other 3D software. When it comes to multiple pieces of geometry with different materials it is best to group them by material used on asset. The object also must be a polygonal piece of geometry – NURBs and other surface modeling creations will not export.

Size

Our current platform does not accept any files that are over 250MB. Ideal size of the file should be lower than 250 MB when uploading to the platform.

Topology:

Going through the optimization process your geometry will most likely be changed to reduce its size for performance, but it is still a good idea to follow proper geometry workflow whenever possible. For faces of geometry use either triangles (tris) or quadrangles (quads), as this will give better results when run through the optimizer. Also check your geometry to make sure all normals are facing the correct way, that smoothing groups are assigned appropriately and that you are not getting any visual errors that would hinder your model.

UVs

It is best practice to create UVs for your assets even if you plan on using a pre-made material due to many materials having texture maps to enhance the material effect. UVs should be located on the base channel as we currently support 1 UV channel.

UV Tiling

In a lot of 3D modeling software you can set the material to tile on its own. However, this tiling doesn’t often translate to an export, and in the case of gltF and usdz, it defaults all materials tilling to 1 x 1, which would make materials that have a pattern that is tiled 15 x 15 (as an example) come out as 1 x 1, and would look much larger.

There are two ways to go about fixing the tiling:

  1. You can use photoshop to create a file where the texture is tiled as much as you need.

Or

  1. You adjust the UV Map to tile by scaling your UVs beyond the 1 value.

Materials and Textures

Rhino3D allows you to export an FBX with material textures,. While it includes a “bump” map, however, it does not convert the bump map into a “normal” map.
To create a material in Rhino3D you need to go to the Material Tab:

In custom material you can determine its name, custom images, such as diffuse (color) and normal maps (bump):

However, the normal map is read as “bump” map and thus cannot be converted into a gltF. The material does store the diffuse and normal map in itself, so programs like 3DS Max can open it up.