Hi there! Thanks for posting in the community. We do have a cylinder shape in our Flowchart shape library but no we do not currently have a specific 3D shapes library. If you'd like you can upload your own shapes if you wish or you can search for images and icons to find something that may work for you. This article goes through how you can do this. Hope this helps!

I would like 3D shapes like cubes too.  Please add this to the shapes library

Agree in addition would like 3d Renderings 

https://lucidchart.zendesk.com/hc/en-us/community/posts/360059342031-3d-Rendering-and-Spatial-representation-of-layers-and-pages-for-Technology-Architecture