pixi-layers clarification

[lasertown]

I'm confused as to why someone would create a group and layer rather than just a layer (which will create a default group if none is given). This part in the documentation I think explains it, but I don't get what's being said:

Quote

When you move a character with attached sprites from different layers to a new stage, you have to change their layers.

Instead, you can create a new display Group:

var lightGroup = new PIXI.display.Group();

bunnySprite.parentGroup = lightGroup;
var lightLayer = new PIXI.display.Layer(lightGroup); // only one layer per stage can be bound to same group

Groups are working between different stages, so when you move bunny it will be rendered in its light layer.

Layer is representation of global Group in this particular stage.

 

Can someone clarify how this API was designed,  or clarify when someone would need a Group to "move between stages?" I'm not exactly sure what this means.

 

Thanks,

Mike

[jonforum]

Hi, here a basic user case of groups
https://pixijs.io/examples-v4/#/plugin-layers/normals-drag.js
Also using on my side, here another user case. 
https://github.com/djmisterjon/ANFT/blob/master/js/game/global/displayGroups.js

I have no more example or good explanation in English sorry.
 

 

[ivan.popelyshev]

Thank you for that question! Usually people dont notice that its kind of optional feature.

Its possible to do everything with just a layer, but you might encounter structural problems.

Group is global, you can use it even without any reference to application/stage/whatever. Instead of "element.zIndex=2" you type "element.parentGroup=group2" , group can be used as that number in zIndex, regardless of layer creation.

 

Edited May 26, 2020 by ivan.popelyshev

[lasertown]

Ok I think I understand the intention now, thanks Ivan!