Ayo.
I created an item and i wanted it to make me jump (but higher than jumping with space, and can be used once after regular jump) and i founded OnUse funcution but can't find anything working for jumping.

 

package com.testmod.item;

import com.testmod.TestMod;

import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.projectile.EntitySnowball;
import net.minecraft.init.MobEffects;
import net.minecraft.init.SoundEvents;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.stats.StatList;
import net.minecraft.util.ActionResult;
import net.minecraft.util.EnumActionResult;
import net.minecraft.util.EnumHand;
import net.minecraft.util.SoundCategory;
import net.minecraft.util.math.MathHelper;
import net.minecraft.world.World;

public class JumpRune extends Item implements ItemModelProvider {

	protected String name;

	public JumpRune(String name) {
		this.name = name;
		setUnlocalizedName(name);
		setRegistryName(name);
        this.maxStackSize = 1;
        this.setMaxDamage(64);
		//setCreativeTab(TestMod.creativeTab);
	}
	
	@Override
	public void registerItemModel(Item item) {
		TestMod.proxy.registerItemRenderer(this, 0, name);
	}
	
	@Override
	public JumpRune setCreativeTab(CreativeTabs tab) {
		super.setCreativeTab(tab);
		return this;
	}
	
    public ActionResult<ItemStack> onItemRightClick(ItemStack itemStackIn, World worldIn, EntityPlayer playerIn, EnumHand hand)
    {
        if (!playerIn.capabilities.isCreativeMode)
        {
        	itemStackIn.damageItem(1, playerIn);
        }

        worldIn.playSound((EntityPlayer)null, playerIn.posX, playerIn.posY, playerIn.posZ, SoundEvents.ENTITY_SNOWBALL_THROW, SoundCategory.NEUTRAL, 0.5F, 0.4F / (itemRand.nextFloat() * 0.4F + 0.8F));
        //playerIn.heal(5f);
        if (!worldIn.isRemote)
        {
        	//playerIn.motionY=0.8;
        	//playerIn.jumpMovementFactor=7f;
        }
        return new ActionResult(EnumActionResult.SUCCESS, itemStackIn);
    }
}

 

Entities have a "motionY" field. I believe that that is what you're looking for. 

34 minutes ago, Lucius Q. User said:

Entities have a "motionY" field. I believe that that is what you're looking for. 

In file (which i gave code in post) i commented motionY because it wasn't working.

Look at what EntityPlayer.jump()does.

Edited July 5, 20178 yr by Kokkie

Remove the !world.isRemote check. 

18 hours ago, V0idWa1k3r said:

Remove the !world.isRemote check. 

Yeah thanks it worked.

 

But.. i have now another problem xD. I tried to limit it to 2 jumps but i don't know what i'm doing wrong :/.

package com.testmod.item;

import javax.swing.text.html.parser.Entity;

import com.testmod.TestMod;

import net.minecraft.creativetab.CreativeTabs;
import net.minecraft.entity.EntityLiving;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.entity.projectile.EntitySnowball;
import net.minecraft.init.MobEffects;
import net.minecraft.init.SoundEvents;
import net.minecraft.item.Item;
import net.minecraft.item.ItemStack;
import net.minecraft.stats.StatList;
import net.minecraft.util.ActionResult;
import net.minecraft.util.EnumActionResult;
import net.minecraft.util.EnumHand;
import net.minecraft.util.SoundCategory;
import net.minecraft.util.math.MathHelper;
import net.minecraft.world.World;

public class JumpRune extends Item implements ItemModelProvider {

	protected String name;
	private boolean hasJumped = false;
	private int jumps = 0;

	public JumpRune(String name) {
		this.name = name;
		setUnlocalizedName(name);
		setRegistryName(name);
        this.maxStackSize = 1;
        this.setMaxDamage(64);
		//setCreativeTab(TestMod.creativeTab);
	}
	
	@Override
	public void registerItemModel(Item item) {
		TestMod.proxy.registerItemRenderer(this, 0, name);
	}
	
	@Override
	public JumpRune setCreativeTab(CreativeTabs tab) {
		super.setCreativeTab(tab);
		return this;
	}
	
    public ActionResult<ItemStack> onItemRightClick(ItemStack itemStackIn, World worldIn, EntityPlayer playerIn, EnumHand hand)
    {
        if (!playerIn.capabilities.isCreativeMode)
        {
        	itemStackIn.damageItem(1, playerIn);
        }
        if(!playerIn.isAirBorne && hasJumped) 
        {
        	hasJumped = false;
        	//System.out.println("(2) isAirBorne " + playerIn.isAirBorne);
        	//System.out.println("(2) hasJumped " + hasJumped);
        }
        if(playerIn.isAirBorne && playerIn.motionY < 0.7 && !hasJumped && jumps <=1) 
        {
        	playerIn.motionY=0.8;
        	hasJumped = true;
        	jumps+=1;
        	//System.out.println("(1) isAirBorne " + playerIn.isAirBorne);
        	//System.out.println("(1) hasJumped " + hasJumped);
        	//System.out.println("(1) jumps " + jumps);
        }
        if(jumps>=2) {
        	jumps = 0;
        	//System.out.println("(1) jumps " + jumps);
        }
        return new ActionResult(EnumActionResult.SUCCESS, itemStackIn);
    }
}

 

Items are singletons. If you set a variable for one it will affect all items. You need to attach either meta data or nbt to an ItemStack instance of the item.