Hello. I have a block that iterates through a 16x16 area for EntityItems, however, I want to add motion towards these entities that 'pull' them towards the said block. I have been trying to do this for quite a while, however, I cannot figure out the math behind it. Currently, I'm finding the relative position of the items from the block and trying to add motion based on this. However, this ultimately failed and I just get items that fly everywhere and look very buggy. Any help would be appreciated.

 

Thanks.

        for(EntityItem item : items)
        {
            double moveFactor = 0.5f;
            double distX = this.pos.getX() - item.posX;
            double distZ = this.pos.getZ() - item.posZ;
            double distY = item.posY+1.5D - this.getPos().getY();
            double dir = MathHelper.atan2(distZ, distX);
            double speed = 1f / item.getDistance(this.getPos().getX(), this.getPos().getY(), this.getPos().getZ()) * moveFactor;

            if(distY<0)
            {
                item.motionY += speed;
            }

            item.motionX = MathHelper.cos((float)dir) * speed;
            item.motionZ = MathHelper.sin((float)dir) * speed;
        }

After more testing, this seems to work, however, the items teleport around in random directions. I'm guessing this is a syncing issue, however, I don't know how to actually fix that. Also, would there be any way to stop the items from stacking with each other, if so, how could I achieve it? 

Edited November 30, 20186 yr by unassigned

7 hours ago, unassigned said:

double dir = MathHelper.atan2(distZ, distX);

 

7 hours ago, unassigned said:

item.motionX = MathHelper.cos((float)dir) * speed;

item.motionZ = MathHelper.sin((float)dir) * speed;

Why are you using trig? If you just want to pull items to a spot then motion is [blockPos - itemPos] / someNumber. 

 

7 hours ago, unassigned said:

Also, would there be any way to stop the items from stacking with each other, if so, how could I achieve it? 

Doesn't look like there is a way to do this.