OpenNest returns more sheets than necessary

Hi there,
if I may adress this to @Petras_Vestartas.
First of all: I am using opennest and it’s super nice! Thank you for this! Amazing work!

Yet I came across some strange results - or maybe I am using it incorrectly.

So I am trying to nest these sheets.

Using these settings I thought I will give the whole thing as much freedom as needed.

Taking a look at it it is of course obvious that 4 rotations will be more efficient and 4 rotations will be sufficient for the whole optimization process.

image

Do more rotations really spoil the result that much or am I missing something here?

Thanks,
T.

Hi,

The thing about nesting in general is that it is n-factorial problem, that means there are a large set of possibilities. Therefore a genetic algorithm is mainly fed by random selected values whose better solutions are passed to the next generation. Knowing this setup, if a user can provide as closer to final nesting configuration as possible the better guess it will be.

In short, yes for rectangles 4 rotations is the best option, and if the rectangles are randomly rotated first, then orient them to the most optimal rectangle before rotation. I have other opennest setup where I add “wigliness” by rotating only within a single degree instead of 360/n. But for cases like this it has no effect…

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@Petras_Vestartas
Okay, understood. :slight_smile:
Thanks for the explanation