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This site contains several projects that heavily utilize the 3D features in Photoshop.
The most recent version of Photoshop has undergone drastic changes to the 3D features leaving some key features used in earlier versions either modified or removed altogether. While new projects going forward will be utilizing the latest version, if you wish to follow along any of the preceding 3D projects you can still install the previous version Photoshop CC 2019 (v20.0.9), which is still available for download in the Creative Cloud App.