Each face should be UV mapped, even if it is done automatically. The configurator supports a second UV set but only for lightmapping. This means that everything in the second set should not be overlapping and should be within the 0-1 legal range.
Use the lowest possible texture resolution. A 512×512 map is ideal, 1024×1024 is acceptable but a bit slower. When viewing the configurator on a mobile platform, all textures will be downsized to 512×512 automatically. In general, stick to powers of 2 (2 x ) for texture sizes.
The most efficient file type is .jpg. Although lightweight, jpg can introduce horrible compression artefacts. If these artefacts are very noticeable consider switching to .png. Png is the standard file type for adding transparency.
The repetition of textures is handled in many different ways across 3d packages. The simplest way to achieve tiling is to scale the UV’s until the desired repetition is achieved. The material editor in the configurator also offers simple means to repeat textures if the desired scale is different between multiple materials.
Most of the problems we have encountered are regarding the UV’s and the texture maps. Usually what happens is that the 3D files we receive contain unique UV/texture sets at the size of 4096×4096. This could create a problem because of the fact that the Expivi platform reduces all imported textures to 1024×1024.
The problem does not lie with the unique UV set, so those must still be created, but with the unique textures that are delivered. What we are suggesting is the following:
For example, take this couch, the product itself contains mainly of two materials (materials, as in the actual materials by which this product is assembled), the fabric and the wooden poles.
What we prefer is that those two components each have their own material (Material, as in a 3D material)
Fabric is indicated by the Blue Colour.
Wood is indicated by the Pink Colour.
This way it is easy for us to manipulate the scale of the material as well as preserving a high resolution.
As for the UV sets, these must still be created uniquely (With all components included), this makes it easy for us to swap them over to the second UV slot and use them for lightmaps.
Conclusion: When a model and it’s UV’s are created the different components must each be assigned to their own material (The material must be named accordingly).The textures must be tileable/seamless for us to scale up the UV’s if necessary. Also, the created UV set must be unique to be used as lightmap UV’s.