Open 0xr.space, press Open and choose the .3mf. Its unit is read, so a part in millimetres opens at its real size, and the build plate's Z up is turned upright. Every placement in the build is drawn, so a plate holding three copies of a part shows three. Bambu Studio and OrcaSlicer projects open too. Info shows the size, the volume and whether the mesh is watertight.
Colours come only from the base materials in the file. Textures, colour groups, multi-property materials and colours painted in a slicer are not read, and those parts are drawn grey. Print settings, supports and the slice itself are not shown: this is the model, not a toolpath preview.
Yes. A 3MF always says its unit, millimetres by default, and it is applied. Info gives the size in millimetres for anything under a metre.
Its colours are stored as textures, colour groups or slicer paint, which are not read. Colours set as base materials are shown.
The mesh has open edges, or edges shared by three or more faces, and the count is shown. The volume is then marked with ~ as an estimate.
No. It is read on the device, and nothing is sent to a server unless you create a share link yourself.