How do I scale a graphics object by global coordinates in PixiJS?

[nikolas]

I have a PIXI.Container object that I need to scale straight up-and-down, by the Y axis of the camera. The object itself is rotated, so I don't want to scale by local co-ordinates.

This will scale the object by local co-ordinates:

container.scale.y = scaleFactor;

 

How do I scale it by global coords by this scale factor? I'm assuming I can use `container.worldTransform` somehow, but I don't understand how to use this.

[ivan.popelyshev]

transform affects only local coord matrix.

the resulting worldTransform is "parent.transform.worldTransform  * this.transform.localTransform". There's no way to do your thing in vanilla pixijs. However, you can hack the transform like i do here: 

https://github.com/pixijs/pixi-projection/blob/master/src/base/LinearProjection.ts#L2

just set "transform.updateTransform = transformHack", where transformHack is your own update function based on https://github.com/pixijs/pixi.js/blob/dev/packages/math/src/Transform.ts#L227

Alternatively, you can scale before rotation is applied by combining two containers: one for scale outside, one for rotation inside.