TL;DR
Why is it so complex to feed products back into the machine?What?
I'd like machines to pull from their output inventory (and maybe also trash inventory) when consuming ingredients. Inserters responsible for input/output can easily be wired to the machine itself for controlled input/output. Theoretically the same applies to fluids, but with those the logistical overhead is less and it also happens less frequently.This should probably be opt-in on the recipe-prototype side, but I can also imagine this configurable by the player per entity in GUI.
Maybe this should be restricted to assembling machines, no furnace types.
I'm on the fence whether the machine simply pulls from the output/trash inventory or whether the items are moved to the input inventory independent of the crafting cycle.
Why?
Look at kovarex processing as an example. Most output has to go into the same machine again. Many large overhaul mods have similar recipes where ingredient and product are the same. Solving that puzzle and building the loops gets old pretty fast, especially when building on a large scale.There can be multiple design reasons for this kind of recipe:
- require a starter amount made from another recipe
- item is considered a catalyst and it makes sense thematically (this suggestion does not apply to catalysts that are "used" and have to be restored, as these are two different items)
- fractional item ingredient per crafting cycle by returning e.g. 95% of the ingredient (instead of scaling up the whole recipe by 20x)
- intentionally make it difficult for the player