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:

Material Modification Order

Remember to perform material modification after the material you wish to modify has been created. The java PostMaterialEvent forge event will always fire after all materials have been created. The kjs GTCEuStartupEvents.materialModification event will always fire after all materials have been created.

JavaJavaScript

AddonMod.java

@SubscribeEvent
public static void materialModification(PostMaterialEvent 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, BlastProperty.GasTier.HIGHER));
}

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.materialModification(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'));

});

Adding fluids to existing materials:

JavaJavaScript

AddonMod.java

@SubscribeEvent
public static void materialModification(PostMaterialEvent event) {
    GTMaterials.Iodine.setProperty(PropertyKey.FLUID, new FluidProperty(FluidStorageKeys.LIQUID, new FluidBuilder()));
    GTMaterials.Oganesson.setProperty(PropertyKey.FLUID, new FluidProperty(FluidStorageKeys.GAS, new FluidBuilder()));
}

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.materialModification(event => {
    GTMaterials.Iodine.setProperty(PropertyKey.FLUID, new $FluidProperty($FluidStorageKeys.LIQUID, new $FluidBuilder()));
    GTMaterials.Oganesson.setProperty(PropertyKey.FLUID, new $FluidProperty($FluidStorageKeys.GAS, new $FluidBuilder()));
});

You can even add an ore to existing materials:

JavaJavaScript

AddonMod.java

@SubscribeEvent
public static void materialModification(PostMaterialEvent event) {
    GTMaterials.Zinc.setProperty(PropertyKey.ORE, new OreProperty());
}

ore_property.js

GTCEuStartupEvents.materialModification(event => {
    const $OreProperty = Java.loadClass('com.gregtechceu.gtceu.api.data.chemical.material.properties.OreProperty');
    GTMaterials.Zinc.setProperty(PropertyKey.ORE, new $OreProperty());
});

Do note that to edit keys that already exist on materials, you have to remove them first:

JavaJavaScript

AddonMod.java

@SubscribeEvent
public static void materialModification(PostMaterialEvent event) {
    GTMaterials.RedAlloy.removeProperty(PropertyKey.WIRE);
    GTMaterials.RedAlloy.setProperty(PropertyKey.WIRE, new WireProperties(8, 1, 0, true));
}

modifying_properties.js

const $WireProperties = Java.loadClass("com.gregtechceu.gtceu.api.data.chemical.material.properties.WireProperties")

GTCEuStartupEvents.materialModification(event => {
    GTMaterials.RedAlloy.removeProperty(PropertyKey.WIRE)
    GTMaterials.RedAlloy.setProperty(PropertyKey.WIRE, new $WireProperties(8, 1, 0, true))
})

You can also add flags to existing materials:

JavaJavaScript

AddonMod.java

@SubscribeEvent
public static void materialModification(PostMaterialEvent event) {
    GTMaterials.Lead.addFlags(MaterialFlags.GENERATE_GEAR);
}

flags.js

GTCEuStartupEvents.materialModification(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:

JavaJavaScript

AddonMod.java

@SubscribeEvent
public static void materialModification(PostMaterialEvent event) {
    GTMaterials.BismuthBronze.setMaterialARGB(0x82AD92); //(1)
}

material_modification.js

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

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