Is there a reason why for such ? I cannot find a reasonable answer to that … Of course we can use setPixels but it seems to be slower.
Well, that has most likely historic reasons. In the past there only was GetPixels and SetPixels (those which uses Color arrays). Finally they implemented GetPixels32 for Texture2D as it was requested by many developers. It’s faster and of course uses only 1/4 the memory. However it seems they didn’t implement those for Texture3D. Maybe they will implement those the other day, maybe not.
You might want to check the feature requests on Feedback
ps. I just did and it’s already there Feel free to vote for it since it only has 11 votes yet: