How to use 3D objects in Omeka s

I have installed Universal Viewer and also IIIF. I am having difficulty with using 3D artifacts as any I have downloaded will not work. Is there a step by step guide for this? I cannot seem to find a simplistic guide for this issue.

Any help would be great, thank you.

Only some 3D objects can be viewed. Next, it depends if the urls inside the medatata are relative if absolute. If they are relative, you need to make them absolute or to install ArchiveRepertory and to follow the readme of Universal viewer.
This is not an ideal solution, but it works.