Hi, I'm trying to create a custom potion effect. I've looked at several tutorials, however all of the ones that I have found are outdated and/or don't make sense to me. I was hoping someone could provide me with a link to an updated tutorial or quickly run down how to do it.

Thanks! 

Extend the Potion class. Done.

 

What a well thought out reply that did not help in the slightest! What next? "Hey guys I need help making this mod work does anyone have any tips?" "Write code."

 

Next time try actually helping the person asking

Right... I had gotten that far, however I somehow doubt that

public class PotionTest extends Potion
{
    public PotionTest(int par1, boolean par2, int par3)
    {
        super(par1, par2, par3);
    }

    public Potion setIconIndex(int par1, int par2)
    {
        super.setIconIndex(par1, par2);
        return this;
    }
}

is all I need. How would I go about actually using the effect?

Thank you very much, I will take a look at this. As you probably get tired of hearing, I am new to modding. You are very obviously not new to any of this. What may be completely obvious and self-explanatory to you, is a very new and complicated world for me.

I've been programming for about 3 years now, albeit rather sporadically across that time frame. I'm quite a slow learner and I take time build a great understanding like you have. I guess for someone like me, this:

 

public void affectEntity(EntityLivingBase p_76402_1_, EntityLivingBase p_76402_2_, int p_76402_3_, double p_76402_4_)
    {
        int j;

        if ((this.id != heal.id || p_76402_2_.isEntityUndead()) && (this.id != harm.id || !p_76402_2_.isEntityUndead()))
        {
            if (this.id == harm.id && !p_76402_2_.isEntityUndead() || this.id == heal.id && p_76402_2_.isEntityUndead())
            {
                j = (int)(p_76402_4_ * (double)(6 << p_76402_3_) + 0.5D);

                if (p_76402_1_ == null)
                {
                    p_76402_2_.attackEntityFrom(DamageSource.magic, (float)j);
                }
                else
                {
                    p_76402_2_.attackEntityFrom(DamageSource.causeIndirectMagicDamage(p_76402_2_, p_76402_1_), (float)j);
                }
            }
        }
        else
        {
            j = (int)(p_76402_4_ * (double)(4 << p_76402_3_) + 0.5D);
            p_76402_2_.heal((float)j);
        }
    }

 

is a bit hard to read at a quick glance.

Read very carefully what the parameters are and it will be really easy to read.

 

This is definitely not the best solution, if you want your potion to be available via the vanilla brewing-stand or if you want to have a nice icon for your effect in the inventory you should just ignore this post!

 

 

 

My personal opinion: potions are even harder to understand than dimensions:

 

potions require a lot of code in your main class = confusing

potions need a picture index for the icon, eveywhere else you can use 16x16 files

you have to use reflection for the recipe  (Notetomyself: create a potion recipe without help. sounds like fun.)

and and and...

 

To be honest, i gave up after 2 minutes and decided to write my own PotionClass:

 

This is actually just a potionitem combined with a standart item. DON'T COPY PASTE IT! REMOVE THE APPLE STUFF FIRST!

 

 

package net.dimensionshiftinfectus.mod.item;

import net.dimensionshiftinfectus.mod.DimensionShiftInfectus;
import net.minecraft.client.renderer.texture.IIconRegister;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Items;
import net.minecraft.item.EnumAction;
import net.minecraft.item.Item;
import net.minecraft.item.ItemPotion;
import net.minecraft.item.ItemStack;
import net.minecraft.potion.PotionEffect;
import net.minecraft.util.IIcon;
import net.minecraft.world.World;
import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;

public class ItemCustomPotion extends Item {

@SideOnly(Side.CLIENT)
private IIcon iconOverlay;
@SideOnly(Side.CLIENT)
private IIcon iconBottle;
private int color;
private PotionEffect[] potion;

public ItemCustomPotion(int maxStackSize, String name, PotionEffect[] potion, int color) {
	this.setMaxStackSize(maxStackSize);
	this.setCreativeTab(DimensionShiftInfectus.tabDimensionShiftInfectus);
	this.setUnlocalizedName(name);
	this.potion = potion;
	this.color=color;
}

@Override
public EnumAction getItemUseAction(ItemStack p_77661_1_) {
	return EnumAction.drink;
}

@Override
public ItemStack onEaten(ItemStack itemStack, World world, EntityPlayer player) {
	if (!player.capabilities.isCreativeMode) {
		--itemStack.stackSize;
	}

	if (!world.isRemote) {
		for (int i = 0; i < potion.length; i++) {
			if (potion[i] != null && potion[i].getPotionID() > 0 && !world.isRemote) {
				player.addPotionEffect(new PotionEffect(potion[i]));
			}
		}
	}

	if (!player.capabilities.isCreativeMode) {
		if (itemStack.stackSize <= 0) {
			return new ItemStack(Items.glass_bottle);
		}

		player.inventory.addItemStackToInventory(new ItemStack(Items.glass_bottle));
	}

	return itemStack;
}

/**
 * How long it takes to use or consume an item
 */
@Override
public int getMaxItemUseDuration(ItemStack p_77626_1_) {
	return 32;
}

@Override
    public boolean onItemUse(ItemStack p_77648_1_, EntityPlayer p_77648_2_, World p_77648_3_, int p_77648_4_, int p_77648_5_, int p_77648_6_, int p_77648_7_, float p_77648_8_, float p_77648_9_, float p_77648_10_)
    {
        return false;
    }

@Override
    public ItemStack onItemRightClick(ItemStack itemStack, World world, EntityPlayer player)
    {

            player.setItemInUse(itemStack, this.getMaxItemUseDuration(itemStack));
            return itemStack;

    }

@Override
@SideOnly(Side.CLIENT)
public boolean requiresMultipleRenderPasses() {
	return true;
}

@Override
@SideOnly(Side.CLIENT)
public boolean hasEffect(ItemStack p_77636_1_, int pass) {
	if (pass == 0) {
		return true;
	} else {
		return false;
	}
}

@SideOnly(Side.CLIENT)
public int getColorFromItemStack(ItemStack par1ItemStack, int pass) {
	if (pass == 0) {
		return this.color;
	} else {
		return 99999999;
	}
}

@SideOnly(Side.CLIENT)
public IIcon getIconFromDamageForRenderPass(int damage, int pass) {

	if (pass == 0) {
		return this.iconOverlay;

	} else {
		return this.iconBottle;
	}

}

@SideOnly(Side.CLIENT)
public void registerIcons(IIconRegister iconregister) {

	this.itemIcon = Items.apple.getIconFromDamage(0);//used for debugging? not sure anymore...
	if (ItemPotion.func_94589_d("bottle_drinkable") != null && ItemPotion.func_94589_d("overlay") != null) {
		this.iconBottle = ItemPotion.func_94589_d("bottle_drinkable");
		this.iconOverlay = ItemPotion.func_94589_d("overlay");
	}

}

}

 

 

 

I only needed this item as a crafting resource so I added a few vanilla effects and never really tried something more advanced with it.

But if you want to create your own effects you have a problem(at least as much as i know) since all effects are connected with potions.

I would simply use nbt data instead, but this way your effect won't be shown in the inventory.

 

You should also add your own brewing stand(just extend the vanilla one) its way simpler than having to use reflection if you are relatively new to java.