I have two geometry node objects. One with ~300 and one with ~90.
I would like to take ~90 instances from the ~300 object and move them to the locations of the ~90 in the other object. But I can't see to find how to randomly grab a specific number.
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Does this answer your question? Geonodes mix position with random index values - How to make random values unique? – Markus von Broady Jun 06 '22 at 10:04
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No. That shuffles all of the elements. I would like to just grab a specific number. – TheJeran Jun 06 '22 at 10:15
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You're right, this is a different question than the one @MarkusvonBroady suggested, but basically it's actually the same problem we have here: The stupid random node can't generate unique values.... – quellenform Jun 06 '22 at 10:21
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1@TheJeran that's pretty much the same, just make a check Index -> Less Than and pass it to a selection or, multiply the boolean (which is 0/1) by the factor of the lerping in the MixRGB node. Saying it's not the same is like saying the poster there wants to move circles, but you want to move squares. – Markus von Broady Jun 06 '22 at 10:40
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What makes this problem potentially different is that with small enough fraction of the entire geometry (below 99% should easily do for my raycasting algorithm there), you shouldn't have to worry about duplicates. – Markus von Broady Jun 06 '22 at 10:44
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This looks to me to reduce exactly to a shuffle-problem, as discussed here. Whichever method you choose, having shuffled the indices, select all instances whose index is less than n, the number you want to move. Having separated the selection, it acquires a new, [0 -> n-1] set of indices:
... and can be aimed at the positions of the [0 -> n-1] index-bearing elements of your target:
Robin Betts
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