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Transform.translate in tiny

Discussion in 'Project Tiny' started by WellC, Jan 1, 2019.

  1. WellC

    WellC

    Joined:
    Mar 2, 2015
    Posts:
    48

    How to implement this movement in Tiny-ecs?
    transform.Translate (Vector3.down * speed * Time.deltaTime, Space.Self);
     
  2. Stijn_RMDY

    Stijn_RMDY

    Joined:
    Nov 14, 2016
    Posts:
    5
    Something like this

    Code (JavaScript):
    1.   let dt = this.scheduler.deltaTime();          
    2.  
    3.             let speed = 2;
    4.             let movement = new Vector3(0, speed * dt, 0);
    5.             this.world.forEach([ut.Entity, ut.Core2D.TransformLocalPosition],
    6.                 (entity, localPosition)=>{
    7.                  
    8.                     localPosition.position.add(movement);
    9.  
    10.                 });
     
  3. WellC

    WellC

    Joined:
    Mar 2, 2015
    Posts:
    48
    Thanks for your reply.
    I tried your codes. It is work fine , but it is no movement by self-space.
     
  4. Nkon

    Nkon

    Unity Technologies

    Joined:
    Jun 12, 2017
    Posts:
    65
    Hi there,

    There are multiple ways to accomplish this. I'll attach an example here that uses a version of Rodriques' formula. In my opinion the pros of this method are ease of writing and avoiding unnecessary operations.

    Code (JavaScript):
    1. namespace game {
    2.     export class SelfMoveSystem extends ut.ComponentSystem {
    3.         OnUpdate():void {
    4.             this.world.forEach(
    5.                 [ut.Entity, ut.Core2D.TransformLocalPosition, ut.Core2D.TransformLocalRotation, game.SelfMove],
    6.                 (entity, localPos, localRot, selfMove) => {
    7.                 // movement speed
    8.                 const speed = this.scheduler.deltaTime();
    9.                 // object rotation
    10.                 const q = localRot.rotation;
    11.                 // required translation in self-space
    12.                 const v = new Vector3(0, speed, 0);
    13.  
    14.                 // rotate v according to Rodrigues' formula
    15.                 const axis = new Vector3(q.x, q.y, q.z);
    16.                 const temp = new Vector3(2 * axis.x, 2 * axis.y, 2 * axis.z);
    17.                 axis.cross(v);
    18.                 axis.add(new Vector3(q.w * v.x, q.w * v.y, q.w * v.z));
    19.                 temp.cross(axis);
    20.                 const move = new Vector3(v.x + temp.x, v.y + temp.y, v.z + temp.z);
    21.  
    22.                 // set new position
    23.                 const pos = localPos.position;
    24.                 localPos.position = new Vector3(pos.x + move.x, pos.y + move.y, pos.z + move.z);
    25.             });
    26.         }
    27.     }
    28. }
    To use the system, create an empty component named 'SelfMove' and add it to a sprite for example. The sprite should then move along its local y-axis.

    Cheers!
     
    ER_Dolleman likes this.
  5. Nkon

    Nkon

    Unity Technologies

    Joined:
    Jun 12, 2017
    Posts:
    65
    In the example, you can remove the calls to cross() and add() by writing the operations manually:

    Code (JavaScript):
    1. const ax = q.y * v.z - q.z * v.y + q.w * v.x;
    2. const ay = q.z * v.x - q.x * v.z + q.w * v.y;
    3. const az = q.x * v.y - q.y * v.x + q.w * v.z;
    4. const tx = q.x + q.x;
    5. const ty = q.y + q.y;
    6. const tz = q.z + q.z;
    7. const move = new Vector3(
    8.         ty * az - tz * ay + v.x,
    9.         tz * ax - tx * az + v.y,
    10.         tx * ay - ty * ax + v.z);
    If you prefer this way, just replace the part under "rotate v according to Rodriques' formula" with the above.

    Cheers!
     
  6. WellC

    WellC

    Joined:
    Mar 2, 2015
    Posts:
    48
    LOL,Thanks you for your reply.
    You solved my big problem.
     
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