Modifying Existing Materials

All periodic table elements are present in GT, but some of them don't have any properties attached. You can also add a BlastProperty for EBF autogenerated recipes. You can also do this for other materials such as Obsidian. Here is how you can add them:

periodic_table_elements.js

    const $IngotProperty = Java.loadClass('com.gregtechceu.gtceu.api.data.chemical.material.properties.IngotProperty');
    const $DustProperty = Java.loadClass('com.gregtechceu.gtceu.api.data.chemical.material.properties.DustProperty');
    const $BlastProperty = Java.loadClass('com.gregtechceu.gtceu.api.data.chemical.material.properties.BlastProperty');

    GTCEuStartupEvents.registry('gtceu:material', event => {

        // Ingot
        GTMaterials.Zirconium.setProperty(PropertyKey.INGOT, new $IngotProperty());
        GTMaterials.Obsidian.setProperty(PropertyKey.INGOT, new $IngotProperty());

        // Dust
        GTMaterials.Selenium.setProperty(PropertyKey.DUST, new $DustProperty());

        // Blast Property
        GTMaterials.Zirconium.setProperty(PropertyKey.BLAST, new $BlastProperty(8000, 'higher', GTValues.VA(GTValues.MV), 8000));

    });

Adding fluids to existing materials requires a bit of work with the new FluidStorage system

fluid_property.js

const $FluidProperty = Java.loadClass('com.gregtechceu.gtceu.api.data.chemical.material.properties.FluidProperty');
const $FluidBuilder = Java.loadClass('com.gregtechceu.gtceu.api.fluids.FluidBuilder');
const $FluidStorageKeys = Java.loadClass('com.gregtechceu.gtceu.api.fluids.store.FluidStorageKeys');

GTCEuStartupEvents.registry('gtceu:material', event => {
    addFluid(GTMaterials.Iodine, $FluidStorageKeys.LIQUID); // Can be LIQUID, GAS, PLASMA or MOLTEN
    addFluid(GTMaterials.Oganesson, $FluidStorageKeys.GAS);
}


let addFluid = (mat, key) => {
    let prop = new $FluidProperty();
    prop.getStorage().enqueueRegistration(key, new $FluidBuilder());
    mat.setProperty(PropertyKey.FLUID, prop);
}

You can even add an ore to existing materials:

ore_property.js

    GTCEuStartupEvents.registry('gtceu:material', event => {

    const $OreProperty = Java.loadClass('com.gregtechceu.gtceu.api.data.chemical.material.properties.OreProperty');

        // Zinc Ore
        GTMaterials.Zinc.setProperty(PropertyKey.ORE, new $OreProperty());

    });

You can also add flags to existing materials:

flags.js

    GTCEuStartupEvents.registry('gtceu:material', event => {

        GTMaterials.Lead.addFlags(GTMaterialFlags.GENERATE_GEAR); // This is for materials already in GTCEU
        GTMaterials.get('custom_material_name').addFlags(GTMaterialFlags.GENERATE_FOIL); // This only works for materials added by GTCEU addons

    });

Editing the color of an existing material:

material_modification.js

    GTCEuStartupEvents.materialModification(event => {
        GTMaterials.BismuthBronze.setMaterialARGB(0x82AD92) //(1)
    })

1. Most methods in the Material class can be used in the materialModification event