Visualisation

[shakethatweight-simon]

Is it possible to know which rotation has been used when an item is packed?

Although we've started with a basic cuboid representation of the objects in the box (we've used Three.js before I noticed you already had a visualisation). We want to upgrade this to use simplified GLTF models of the items. At the moment the only thing I can think of is comparing the original dimensions to the final dimensions to determine it.

[dvdoug]

Hi @shakethatweight-simon

You want to draw the actual items, not just an encapsulating cuboid? (where those things are different).

I think your identified solution is probably the only feasible one, there is nothing in BoxPacker itself that stores that kind of information and I can't see an easy way of adding it. The data structures are arrays, but the keys are already used for deduplication and then assumed not to matter.

Happy to take a look at PR in theory though if you think it could be done without regressing performance. The starting point would be here: https://github.com/dvdoug/BoxPacker/blob/3.x/src/OrientatedItemFactory.php#L226.

[shakethatweight-simon]

@dvdoug at first glance it seems like rekeying the array to provide orientation information might be the starting point.

        //simple 2D rotation
        $permutations['O'] = [$w, $l, $d];
        $permutations['Y'] = [$l, $w, $d];

        //add 3D rotation if we're allowed
        if (!$item->getKeepFlat()) {
            $permutations['Z'] = [$w, $d, $l];
            $permutations['YX'] = [$l, $d, $w];
            $permutations['YZ'] = [$d, $w, $l];
            $permutations['X'] = [$d, $l, $w];
        }

This assumes:

• X axis is the Length
• Y axis is the Width
• Z axis is the Height ?

Just wanted to check this with you first before taking it further, I can see other sections of code that would need to be updated too.

If I mange to make some changes, do you want me to use 3.x as the starting point for the changes or master?

---

Notes to self

(none of this has been tested)

https://github.com/dvdoug/BoxPacker/blob/3.x/src/OrientatedItemFactory.php#L92 - uasort

https://github.com/dvdoug/BoxPacker/blob/3.x/src/OrientatedItemFactory.php#L121 - add key to $orientations

https://github.com/dvdoug/BoxPacker/blob/3.x/src/OrientatedItemFactory.php#L177 - add key to $stableOrientations $unstableOrientations

https://github.com/dvdoug/BoxPacker/blob/3.x/src/OrientatedItemFactory.php#L96

$this->appliedRotation = key($orientations);
return $orientations[$this->appliedRotation];

[dvdoug]

Yes, 3.x please as it's easier to merge up than backport. X axis is width, Y is length, Z is depth.

Thinking about it a bit now, the dimension comparison calculations you were looking as a fallback for your own application - maybe adding a new getter into PackedItem to basically do that would be easier than generating meaningful keys deep in the core and then propagating them outwards?