No, it was a greyscale image of a 3d rendering (or at least an AI approximation of one). This is also called an occlusion map or a white model. These are the types of files you use to make those fake 3d engraves that are actually pretty much flat:
They produce something like this:
By contrast, in the example from the video you can see that it is radically transformed by the end to be an approximation of a true 2.5-D height map.
Original:
End result:
More info:
And again the original in this example is neither an occlusion map nor a height map because it’s AI generated. It’s simply imitating an untold number of 3D renders of white models that the AI model found during training.
So while I can’t say exactly what the original from the video is, I can say it definitely is not a 2.5-D heightmap model — and technically, neither is the end point since it’s also AI generated. It’s only optimized to be like other engravable 2.5D examples by a very specifically trained AI model.
Good result though!