question about material section in TOS

I have reviewed the TOS and was wondering if the TOS allows me to import materials from the asset store to gimp 2.8 to create bump maps for them?

I would strongly argue that such usage comes under the “intended purpose of the asset”, and so long as the bump maps you create are then incorporated within your game, that would be fine.

If you were creating bump maps of an existing texture pack and then trying to resell them as a separate product, however, that might be different since you’d be creating a derivative work.