How pivot and position work for root container?

[FredLin]

The stage property on the app we create is the root container of everything that we want to render with PIXI. From what I see in the console, the root container doesn't have its own parent. The default pivot and position for it are both (0, 0), which is the top-left corner of the container.

By default, the children are added at (0, 0), which is now the top-left corner of the root container. I want them to be added at the geometric center of the container so naturally I did stage.pivot.set(renderer.width / 2, renderer.height / 2). However, this doesn't work. Instead, stage.pivot.set(-renderer.width / 2, -renderer.height / 2) gives me the expected result. Could someone explain to me the logic behind this?

Also, from what I understand, position is relative to the parent coordinate. Since stage doesn't have a parent, what does stage.position actually represent?

[ivan.popelyshev]

position in world coords is pinned to pivot in local.

for example, i want to show a map centered on character.

stage.position.set(renderer.screen.width/2, renderer.screen.height/2); //not view!!! start using DPR>1 and you'll understand why ;)
stage.pivot.set(character.x, character.y);

stage.scale.set(2); //zoom it!