The filtering hopper acts like a hopper, but will only accept items into its inventory that can be inserted into the specified inventories from a given direction, operating on a "does this machine take this input?" basis rather than an item-by-item basis.
Using the Filtering Hopper[]
At first, the Filtering Hopper will be unable to accept any items, as shown at the left. In order to configure it, you need to insert any block that has an inventory, furnace, chest, or millstone. The Filtering Hopper will make a phantom clone of the block, leaving the original attached to your mouse.
Generally speaking, an inventory that accepts all items (such as the chest) isn't going to be very useful, but they will work. Note that the furnace does technically accept any items into its slots, but the Filtering Hopper has special handling to determine fuel or smeltable.
Each of the six container slots operate on only one side of the supplied block, checking for valid insertion from above, from the side, or from below. Many inventory blocks have sided inventories, only allowing access to some slots based on which face the accessor is placed on. The furnace can only take smeltables from above and fuel from the sides, with results (and fuels) extractable from below.
Once there is a filter specified, the Filtering Hopper is ready to extract items from other inventories or have them pushed into from another hopper and the warning message will go away.
Lastly, there is a logical operator button, which will cycle between four modes:
ANY, ALL, SOME, and NONE.
- ANY is just as it is, the Filtering Hopper will accept items as long as it can be inserted into at least one of the filter inventory rules.ALL means that only items that can be inserted into every filter inventory rule.SOME means that the item must be inserted into at least one but not all of the filter inventory rules.NONE means that the item cannot be inserted into the filter inventory rules at all.
The graphic, left, is out of date and corresponds to the NONE option (image is out of date), but for example, this Filtering Hopper will only accept items that are invalid for the millstone: gravel, dirt, sticks, and so on. Ore chunks, wheat, and sugar will not go into the Filtering Hopper.
This is because the millstone is in the rule slot corresponding to top insertion and the millstone accepts items via the top face, provided that they are grindable and we set the logic operator to say we don't want those items.