I am using WWW class to download the 3d model at Resources folder in my project.
But when it comes to instantiate that model. (using Resource.load(path)).
the error pops up: ArgumentException: The thing you want to instantiate is null.
2673872–188754–Render.cs (604 Bytes)
2673872–188755–StartDownload.cs (855 Bytes)
Unity uses its own internal representation for meshes (see Mesh), you can’t simply load a mesh encoded in a different format from a build, that’s possible only from the Editor. You would need to convert the meshes the native Unity format, or write a function that would read the file and build a mesh from it.
We provide no runtime 3d model importers.
You could convert the model into an asset bundle and download that or look into a runtime importer, the asset store has some.