Honkai: Star Rail has a fair number of materials. You use them to upgrade things like Light Cones, Traces, etc. Thankfully, the game has a built-in system that tells you where most of these materials are. Thus, you can go to those areas and farm for them. Here’s how to access that function. Please note that this doesn’t work for every material. In general, premium currencies like Stellar Jade, for example, are not farmable.