You will find a lot of web sites and marketplaces with 3D models. What you want to look for is low poly (Low amount of polygons). It means, in general, it will be compatible with AR and VR headsets.
You will find some professional 3D models with a very high number of polygons and high-resolution textures in the websites listed below. They are often not compatible with AR and VR as they are used for reality 3D render videos of pictures.
low poly usually means a 3D model under 50,000 polygons. This will guaranty they will load smoothly and not affect performances.
Last, there are dozens of 3D formats in which 3D models are made. None of them are compatible with each other.
You will want to look for models with the format GLB or GLTF.
AfterNow Prez supports GLB and GLTF format natively without any conversion needed.
In short, when you browse the website listed here, look for Low Poly and GLB or GLTF downloadable 3D models.
General
Those are communities of 3D modelers that post 3D models. They are repositories and marketplaces. The content quality can vary greatly.
They mostly support GLTF format making it easy to import in AfterNow Prez remote presentation.
Sketchfab
It's one of the largest libraries with an easy to use user interface and great web viewer.
Make sure to select in Explore -> Downloadable to select only 3D models that can be downloaded. You can also search the store that contains mostly downloadable 3D model.
Sketchfab support GLTF by default.
Google low poly:
Its google library of user-generated content from Tilt Brush and Blocks. The content is more amateurish, but you can find some low poly gems.
Make sure to select in the top left menu: Blocks for mostly easy to download and import models.
Clara.io
Many free 3D models, Clara.io, don't support GLTF by default so there will be an extra step to convert the models for AfterNow Prez Remote.
not so free 3D models:
Many models of various quality, a lot of paid ones, and most of them do not support GLTF, so additional steps will be needed to import in AfterNow Prez.
Professionals
The professional web site often contains high polygon 3D models and will often require conversion to Unity or GLB.
Check out of the article on how to convert 3D models to work for AfterNow Prez remote.
The quality of the model is generally much higher with more realistic and business-centric content.
A lot of the professional models are for photography or video animation but not ready for virtual reality or augmented reality. Some will require additional steps to be integrated in AfterNow Prez. Subscribe to our mailing list we will have a tutorial soon on how to convert 3D models.
Turbosquid
Adobe
https://stock.adobe.com/search?filters[content_type%3A3d]=1&filters[3d_type_id][0]=1&load_type=3d+lp
CG Trader
Grab Cad
Sketchup 3D warehouse:
https://3dwarehouse.sketchup.com/?hl=en
3D export:
Museums
A few museums have started to scan their collections and post them on the web.
Those are often free and of excellent quality.
Smithsonian:
https://3d.si.edu/
https://www.smithsonianmag.com/smart-news/you-can-now-download-1700-free-3-d-models-cultural-heritage-artifacts-180974308/
The British museum
https://sketchfab.com/britishmuseum
https://blog.britishmuseum.org/a-new-dimension-in-home-shopping/