I realize I hadn't been very clear regarding how to properly export your 3D sandbox items.

So I updated the guide with a new section - under "Testing Content in the Sandbox", see the new header "Exporting".

http://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=425217999

Basically, by default people are exporting the entire scene, and that can make it very difficult when I'm integrating the item to pick out the relevant items and re-assemble. Additionally, this export function can leave out critical components if they didn't exist in the scene.

So, the new suggested method is to make sure your item exists as a prefab, within a dedicated item folder (containing all other item materials and meshes as well), and then select the prefab before hitting 'Export'.

This makes sure that you're only exporting the assets that apply to the prefab.

Thanks!