Using Polymorph with JEI/REI and Automation Setups

Interacting with Recipe Viewers

Recipe viewers like JEI or REI list every recipe, including duplicates, but they cannot tell the game which one to craft. Polymorph fills that gap. When you click a recipe in the viewer to auto-fill a crafting table, the ingredients land in the grid and the Polymorph button appears above the output — use it to confirm you are getting the variant the viewer showed you.

Automation and Hoppers

Be aware of how automation behaves:

• Hoppers and pipes pulling from a crafting table or furnace take whatever output is currently selected. They do not open the selector for you.
• Because smelting choices are saved to the block, an automated furnace keeps producing your chosen output across reloads — set it manually first, then let automation run.
• For crafting automation that bypasses the grid entirely (auto-crafters from other mods), Polymorph's selector may not apply, since those systems resolve recipes their own way.

Recommended Workflow

1. Set up the block manually and pick your output.

2. Verify one craft/smelt produces the correct item.

3. Only then attach hoppers or pipes.

This avoids a common frustration where automation silently outputs the wrong mod's item because no one ever opened the selector.