How to Use /profile to Scan a World's Ore Distribution

If you're a pack maker or an experienced player who wants real numbers instead of guessing, JER's /profile command scans a generated world and records its actual ore distributions. Here's the workflow.

Running the Scan

Generate or load a world you want to analyze. Open chat and run /profile with a chunk amount argument to control how many chunks get scanned, and optionally the all argument to include every registered ore rather than a subset. The command walks through the generated chunks, counts ore placements per Y-level, and writes the results out.

Where the Output Goes

JER saves the scan as a world-gen-scan.json file in its config folder. This file contains the measured distributions pulled straight from the world, so you don't have to estimate spawn rates by hand. You can then use that data as a reference when building or tuning your own world-gen configuration.

Practical Notes

• Larger chunk amounts give smoother, more reliable graphs but take longer to run.
• Scan a world that uses the generation settings you actually care about, since results reflect that world's config.
• This is an advanced feature aimed at pack makers; casual players can rely on the JEI world-gen tab instead.
• Keep the generated JSON as a baseline before you change any ore settings.