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[giozecc]

Hi dvdoug,

and thank you for this wonderful tool. Very fast, very smart.

My question is about packing in the vertical direction. It seems that your algorithm allows producing very compact layers, but it does not create a compact stack.
This can happen when, in a bottom layer, there is a box higher than the others, like in the picture

Is there anything that I'm forgetting to do?

Here you can find the test

$packer = new Packer();
$packer->addBox(new TestBox('EPAL', 1200, 800, 3000, 1000, 1200, 800, 3000, 1800000));
$packer->addItem(new TestItem('Item 1', 250, 250, 200, 28000, false), 20);
$packer->addItem(new TestItem('Item 2', 150, 250, 200, 12000, false), 20);
$packer->addItem(new TestItem('Item 4', 125, 200, 100, 7000, false), 20);
$packer->addItem(new TestItem('Item 3', 250, 200, 200, 24000, false), 20);
$packedBoxes = $packer->pack();

Thank you

[dvdoug]

Hello @giozecc

What you're seeing is currently "by design" - the algorithm works by building "layers". Once each layer is built, the next layer on top is built assuming a flat horizontal surface (i.e. it doesn't know what came before). This means that the calculated position of a box does indeed sometimes "float".

I'm currently of the belief that adjusting this to take account of space in the layer(s) beneath to more accurately model reality would probably be too computationally expensive to be worthwhile, but I haven't ruled it out completely for the future - there might be some tricks that e.g. game engines use for calculating bounds that could be adapted.

Relevant code starts at https://github.com/dvdoug/BoxPacker/blob/3.x/src/VolumePacker.php#L205 if you're interested.