Hello!  I have been working on spawning these flame particles and I have run into a problem...  I want to spawn more of them so I am trying to do this by decreasing the value in the for loop but whenever I set it below 1 it sometimes crashes when they spawn in.

 

 

When the .5 is 1 there is no crash and when its lower it sometimes crashes.

@Override
@SideOnly(Side.CLIENT)
public ItemStack onItemRightClick(ItemStack stack, World world, EntityPlayer player){

	MovingObjectPosition objectMouseOver = player.rayTrace(5, 1);

	if(objectMouseOver != null)
	{
		for(double x = 5D;x>0D;x = x-.5){	
			world.spawnParticle("flame", objectMouseOver.blockX+(Math.random()), (objectMouseOver.blockY+.75D)+(Math.random()), objectMouseOver.blockZ+(Math.random()), 0.0D, 0.0D, 0.0D);
			System.out.println(x);
			objectMouseOver = player.rayTrace(x, 1);

		}
	}	


		return stack;
    }

 

 

Crash Report

---- Minecraft Crash Report ----

// My bad.

 

Time: 7/12/16 9:56 PM

Description: Unexpected error

 

java.lang.NullPointerException: Unexpected error

at com.example.examplemod.ItemStar.onItemRightClick(ItemStar.java:50)

at net.minecraft.item.ItemStack.useItemRightClick(ItemStack.java:164)

at net.minecraft.client.multiplayer.PlayerControllerMP.sendUseItem(PlayerControllerMP.java:430)

at net.minecraft.client.Minecraft.func_147121_ag(Minecraft.java:1557)

at net.minecraft.client.Minecraft.runTick(Minecraft.java:2044)

at net.minecraft.client.Minecraft.runGameLoop(Minecraft.java:1039)

at net.minecraft.client.Minecraft.run(Minecraft.java:962)

at net.minecraft.client.main.Main.main(Main.java:164)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.lang.reflect.Method.invoke(Unknown Source)

at net.minecraft.launchwrapper.Launch.launch(Launch.java:135)

at net.minecraft.launchwrapper.Launch.main(Launch.java:28)

at net.minecraftforge.gradle.GradleStartCommon.launch(Unknown Source)

at GradleStart.main(Unknown Source)

Is the method

onItemRightClick

marked as

@SideOnly(Side.CLIENT)

in the Item class?

It is not, I tried removing it but it still crashes sometimes with the same crash report.

It is not, I tried removing it but it still crashes sometimes with the same crash report.

 

Well of course it still crashes.

 

Inside the loop you're doing a raytrace at increasingly shorter distances.  What do you think happens when that raytrace doesn't hit something?

Thank you for that hint!  I see what i did, lol and it now works!  But why would it never crash if the value I was adding was 1?  And if others want to know how i fixed it,  i forgot to check if it was null in the for loop.

If the raycast hits with distance 5, then its guaranteed to hit if the distance is 6 instead.

 

However, it is not guaranteed to hit if the distance is 4...