Enderpearl Trajectory

I've never looked at the actual code behind enderpearls flight path, but are the close to reality.
Do they follow a parabolic flight path?
Are they effected by deceleration (does mc emulate slowing due to friction)?
Does the initial velocity stay relative to the player, or to the earth (If I run and throw, does it go further than standing still)?
And finally, what would be the easiest way to find its collision point (i'm not fussed about entities, just blocks for now)?

Thanks.

 

*shameless bump*
Any ideas or suggestions?

 

Do they follow a parabolic flight path? - I don't even know what that means.
Are they effected by deceleration (does mc emulate slowing due to friction)? - Yes...kind-of
Does the initial velocity stay relative to the player, or to the earth (If I run and throw, does it go further than standing still)? -Earth
And finally, what would be the easiest way to find its collision point (i'm not fussed about entities, just blocks for now)? - http://forums.bukkit.org/threads/tutorial-get-the-block-where-a-projectile-landed.176395/

https://github.com/Bukkit/CraftBukk...t/minecraft/server/EntityProjectile.java#L164
Read that.

 

Garris0n
Thanks for the other info

If I throw it from height y1 (and position x1) and it reaches a height of y2, and then lands at y1 (of position x2) again. y2 should be at the position of (x1 - x2) /2. Wikipedia article for more info:http://en.wikipedia.org/wiki/Trajectory#Range_and_height

Explain...

 

It means is the flight path in the shape of a parabola, and the answer is yes.

 

I was hoping to get it at the start of flight, not at the end :S

 

If you're looking to find where the enderpearl is thrown from, just use a ProjectileLaunchEvent, check to see if the projectile's shooter is a player, and if the projectile is an enderpearl, then save the location or do whatever.

Code:java

 
    @EventHandler
    public void enderpearlThrow(ProjectileLaunchEvent e) {
 
        if(e.getEntity() instanceof EnderPearl && e.getEntity().getShooter() instanceof Player) {
 
            Player p = (Player) e.getEntity().getShooter();
 
            /* do whatever */
 
        }
 
    }

 

Vexil
I meant, as soon as the player throws it, find where the enderpearl will end up hitting. I guess I could emulate the flight in one tick?

 

That may be a small bit more difficult than it seems. You would have to calculate the flight of the enderpearl. Have you looked at the source to find out exactly how the trajectory is calculated?

 

Yes!

...no

 

You are going to have to do a bit of math. I would look for a mod that has a trajectory shower for enderpearls, kind of like a line that goes from your location to where the mod has calculated the enderpearl to land, and look at the source code. Otherwise try to preform some tests in game with adjusting your angle. I would play with vectors if I were you.

 

Vexil
I'm thinking I might just use nms and iterate through the flight path. Do you reckon that would be too much to process in a game tick?

 

Well, considering NMS does it, probably not unless a lot of people are spamming enderpearls.

 

Vexil
Enderpearls will be a rarity where I will be using this, so hopefully that will moderate it. Are you able to help with the nms part (nms virgin here :3)?

 

Well that means you have room to learn! Trust me, it isn't that hard. It'll be good for you
https://github.com/Bukkit/mc-dev/tree/master/net/minecraft/server

 

What are you using this for? You can set the velocity of a thrown projectile, such as an enderpearl. You can use some equations to get the vector velocity coordinates and then set the velocity to that new vector.

 

maxben34
I don't want to change it. I just want to predict where it will land, as it is being shot

Vexil
I have CB's NMS' EntityProjectile open in eclipse and it is not even similar apart from some of the methods to the git hub

EDIT by Moderator: merged posts, please use the edit button instead of double posting.

 

If you have a preset velocity you can get the location where it's launched and the set velocity and then get the final location of that. I'm pretty sure you're looking at a parabolic trajectory here.