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Rotate entities arround circle

Discussion in 'Help' started by felony13twelve, Nov 28, 2022.

  1. felony13twelve

    felony13twelve Creeper

    I want to make such an animation as in the video - I know that I need cosine, sine, etc. but my knowledge does not allow me to write it, because I don't know geometry well. Please help me to do this.
  2. Primus

    Primus Zombie Pigman

    Start by spawning them in circle, then move by an angle offset.
  3. LearXD

    LearXD Creeper

    I believe you already know how to generate entities, so let's get down to business, the Mathematics behind it.

    To make a circle we're going to use the sine and cosine of an angle that will show us a position on the circle, then we're going to multiply both by the radius, since the default "radius" of sine and cosine is 1.

    As the amount of items can vary, I made a calculation that will correctly distribute them in the circle...

    Code: (I haven't programmed in pocketmine for a while, so I know the API works correctly, so please follow this code as a guide, not a solution...)

    use pocketmine\item\Item;
    use pocketmine\math\Vector3;
    const RADIUS = 3;
    protected $items = [];
    protected $center;
    protected $turns = 0;
    //Your constructor function
    public function __construct(array $items) {
        $thos->items = $items;
        $this->center = new Vector3(0,0,0);
    //Your loop can be a ScheduleTask
    public function loop() {
        $pi = 2 * M_PI;
        $cicles = 1 / sizeof($items);
        foreach ( $items as $i => $item ) {
            $x = sin($pi * ($i * $cicles)) * RADIUS;
            $y = cos($pi* ($i * $cicles)) * RADIUS;
            // X, Y, Z (using only Y,Z)
            $item->teleport($this->center->add(0, $x, $y));
        $this->turns += $cicles;
        $this->items[] = array_shift($this->items);
        if ($this->turns >= 1) { //1 = 100%
            // 1 turn completed, you can stop here
    Primus likes this.
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