Until now, we have been using different out-of-the-box 3D objects that come with built-in geometries. The FireMonkey library provides the TModel3D component that makes it possible to use geometries defined outside of Delphi, typically using a 3D modeling software and importing mesh data from one of the supported 3D file formats.
FireMonkey supports importing 3D models from OBJ, DAE, and ASE file formats. These are standard formats supported by many 3D modeling software packages.
If you have 3D modeling artistic skills then you can create your own models. Many programmers don't, so they need already existing models for their 3D apps. There are many websites offering free and commercial 3D models. One of them is www.turbosquid.com where I found a nice royalty-free OBJ model of a medieval helmet (https://www.turbosquid.com/3d-models/free-3ds-model-medieval-helmet...