Hey Chunck! I might get my answer in the next chapter but I was wondering why we didn't export the height channel here since we've used it quite often?
Great question!
Height map textures are usually used for vertex displacement on a model, like creating a terrain mesh from an image or using a displace modifier with a height texture to create displaced geometry for the trunk of a tree.
For a model like our wand, we won't be doing any displacement since that requires a ton of vertices to appear high-quality enough. Instead, we will be using a Normal map with baked detail, as well as detail added in the texturing stage.
The reason we use Height information throughout the texturing stage is because it is easier to represent elevation and depressions into a surface using a grayscale 0-1 range. We can understand the if we want elevation, we can add "value" to that area, and depressions we remove "value". The Height map is the texture that holds that information for us while we texture, but what's going on behind the scenes with InstaMAT (and other texturing apps) is that it is converting it into Normal map data.
So while we never have to intentionally export a Height map, in a way we are still exporting that data, it is just converted into a Normal map. This is beneficial because like I've mentioned, we want to keep this a lower-poly model. We won't have the appropriate amount of vertices to allocate to this model for high-quality displacement. So a Normal map will give the "idea" that there is height variation on a surface, even though we won't need to model that detail.
If you want to take a look at this yourself, in InstaMAT if you switch to the Normal channel view (C hotkey on your keyboard, M to return to regular), and you toggle on and off the Metal>Base layer, you'll see that even though it is set into the Height channel, it will also be updating the Normal channel as well. It is a little hidden from our view, but that's what's really going on behind the scenes!