How to add custom elements into custom materials? | GregTech CE Unofficial | Page 1

solar dust Jan 18, 2026, 11:29 AM

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I ran into a new issue, I tried to replicate GT:NH's Black Plutonium, so I coded:

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

    event.create('sp')
        .protons(1000000)
        .neutrons(1000000)
        .halfLifeSeconds(-1)
        .decayTo(null)
        .symbol('Sp')
        .isIsotope(false)

})

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

    event.create('black_plutonium')
        .ingot()
        .components('1x sp', '1x plutonium')
        .color(0x222222).iconSet(GTMaterialIconSet.ROUGH)
        .flags(
            GTMaterialFlags.GENERATE_PLATE
    )
})

But the actual result presented is like the attatched image.

It only has plutonium in it.

GT Modern Version: v7.4.1

lean viper Jan 18, 2026, 3:07 PM

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solar dust I ran into a new issue, I tried to replicate GT:NH's Black Plutonium, so I coded...

you need to create a material for your Sp element first

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e.g.

        Copper = new Material.Builder(GTCEu.id("copper"))
                .ingot(1)
                .liquid(new FluidBuilder().temperature(1358))
                .ore()
                .color(0xe77c56).secondaryColor(0xe4673e).iconSet(BRIGHT)
                .appendFlags(EXT_METAL, MORTAR_GRINDABLE, GENERATE_SPRING, GENERATE_SPRING_SMALL, GENERATE_RING,
                        GENERATE_FINE_WIRE, GENERATE_ROTOR)
                .element(GTElements.Cu)
                .cableProperties(V[MV], 1, 2)
                .fluidPipeProperties(1696, 6, true)
                .buildAndRegister();

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by saying .element it's a material for an element

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then with that you can make composites

solar dust Jan 18, 2026, 3:08 PM

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the .element() is the same as the .element() in material registry?
like .element('sp')

lean viper Jan 18, 2026, 3:08 PM

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yeah

solar dust Jan 18, 2026, 3:09 PM

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let me try this, wait a few second

lean viper Jan 18, 2026, 3:09 PM

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they might have to be in differnet idfles with priorities? not 100% sure

solar dust Jan 18, 2026, 3:12 PM

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Sp = new Material.Builder(GTCEu.id('sp'))
    .liquid(new FluidBuilder().temperature(100000))
    .color(0x00000)
    .iconSet(ROUGH)
    .appendFlags(EXT_METAL)
    .element('sp')
    .buildAndRegister();

like this? im a bit confused now

#

smoothbrain

lean viper Jan 18, 2026, 3:13 PM

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what I sent is java code, you'd need to find some equivalent js code

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lemme see if I can find some

solar dust Jan 18, 2026, 3:13 PM

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ok

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you still there?

lean viper Jan 18, 2026, 3:27 PM

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Couldn't find some easily in existing repos sadly. try something like

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

    event.create('sp')
        .protons(1000000)
        .neutrons(1000000)
        .halfLifeSeconds(-1)
        .decayTo(null)
        .symbol('Sp')
        .isIsotope(false)

})

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

    event.create('cosmic_neutronium')
        .ingot()
        .element(GTElements.get('sp'))
        .color(0x222222).iconSet(GTMaterialIconSet.ROUGH)
        .flags(
            GTMaterialFlags.GENERATE_PLATE
    )

    event.create('black_plutonium')
        .ingot()
        .components('1x cosmic_neutronium', '1x plutonium')
        .color(0x222222).iconSet(GTMaterialIconSet.ROUGH)
        .flags(
            GTMaterialFlags.GENERATE_PLATE
    )
})

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something like that

solar dust Jan 18, 2026, 3:27 PM

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wait

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i got it

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earlier

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we're thinking the same solution

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solved

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

    event.create('pure_plutonium')
        .protons(1000000)
        .neutrons(1000000)
        .halfLifeSeconds(-1)
        .decayTo(null)
        .symbol('Pu')
        .isIsotope(false)

    event.create('sp')
        .protons(1000000)
        .neutrons(1000000)
        .halfLifeSeconds(-1)
        .decayTo(null)
        .symbol('Sp')
        .isIsotope(false)

})

GTCEuStartupEvents.registry('gtceu:material', event => {
    
    event.create('sp')
        .element(GTElements.get('sp'))
        .color(0xffffff).iconSet(GTMaterialIconSet.DULL)
    
    event.create('pure_plutonium')
        .element(GTElements.get('pure_plutonium'))
        .color(0xffffff).iconSet(GTMaterialIconSet.DULL)

    event.create('black_plutonium')
        .ingot()
        .components('1x sp', '1x pure_plutonium')
        .color(0x222222)
        .secondaryColor(0x000000)
        .iconSet(GTMaterialIconSet.SHINY)
        .flags(
            GTMaterialFlags.GENERATE_PLATE
    )
})

lean viper Jan 18, 2026, 3:38 PM

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awesome hapybapycat

solar dust Jan 18, 2026, 3:40 PM

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thank you

mellow raptor Jan 18, 2026, 9:59 PM

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Space is already registered as a GTCEuM element along w/ magic

lean viper Jan 18, 2026, 10:00 PM

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mellow raptor Space is already registered as a GTCEuM element along w/ magic

sp isn't space, sp is cosmic neutronium from gtnh

mellow raptor Jan 18, 2026, 10:00 PM

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Oh, ok

solar dust Jan 19, 2026, 12:28 AM

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lean viper sp isn't space, sp is cosmic neutronium from gtnh

SpNt is cosmic neutronium from gtnh, technically

#How to add custom elements into custom materials?