Hi the Std edition export 3d file is not godd, please try Pro edition, support to export step https://pro.easyeda.com/editor

To avoid having to install an app to view the object you can use this online viewer: [https://www.creators3d.com/online-viewer](https://www.creators3d.com/online-viewer) Notice the top surface of the pcb is invisible if viewed from the top, but if you angle the board right (look from the side), you can see the surface is visible from underneath, as if the surface normal is backwards. Same with all the sides. The back surface looks ok, although that might just be luck, the rendering code might just be assuming the bottom surface normal points down or something...

I have published a test project to demonstrate this: [https://oshwlab\.com/hamiditized/3d\_obj\_test](https://oshwlab.com/hamiditized/3d_obj_test)<br> <br> Open the project, export it to Obj file, open the exported file in, say, Ultimaker Cura (free cross-platform download), and you can see the error message about the surfaces at the bottom (see screenshots attached to above project). I also have screenshots from XCode 3D viewer attached to the above project showing missing surfaces. It may be that the surface normals are all backwards.

Screenshots? Examples?