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I'm using generated texture images to set the individual colors, emission strengths, and sizes of 119,617 stars imported from the Hipparcos catalog. My texture images are each a single row of 119,617 pixels and I'm wondering if Blender will accept it without capping it at certain maximum.

(I noticed in the Texture tab that when I select the texture image, its x-size shows as ~65,000 (going by memory), and that while I can decrease this number, I cannot increase it. This has made me suspect that there is a size limit that I hadn't thought of.)

Thanks in advance if you know the answer and are willing to share it. I'd like to work with even more particles (millions, if Blender will allow me), so size limits of this sort are definitely something I should be aware of!

EDIT: I realize now that the ~65,000 limit appears on Mac OS but not on Windows. The same model that on Windows correctly shows 119,617 pixels for the X dimension of the texture image shows only 65536 on my MacBook Pro. Wondering why that would be? V2.78 on Windows and 2.76 on Mac.

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  • $\begingroup$ If I understand correctly, you generate the image in some other application, or acquire it elsewhere, and the problem is that Blender caps the size? I just tried importing a 131072x1 OpenEXR, and it imported at the full size in both Blender Internal and Cycles. It may be something with the image format. $\endgroup$ – Duane Dibbley Aug 13 '18 at 22:36
  • $\begingroup$ I cleaned up my Python script, tried again, and—to my great pleasure—saw that the image width was now the 119,617 pixels that I originally expected. If there is a size limit in Blender, I would still love to know of it (before I start generating texture images millions of pixels in width), but in this particular model, this now seems to be a nonissue. Thanks, Duane, for responding! $\endgroup$ – Alex Aug 13 '18 at 23:53
  • $\begingroup$ You're welcome. And about a limit, I do not know (but it's possible someone else does). I tried, just to have tried, to create a 131072x131072 image, but just as I expected, my computer froze for some time, until it panic rebooted due to out of memory. $\endgroup$ – Duane Dibbley Aug 13 '18 at 23:58
  • $\begingroup$ How about that? I've been so concerned with software limitations that I hadn't thought about hardware limitations. It's possible that hardware limitations will force a cap on image sizes before you hit the biggest size allowed in Blender, if such a size limit should exist. Thanks! $\endgroup$ – Alex Aug 14 '18 at 0:35
  • $\begingroup$ 131,072x131,072 is rather extreme. 32 bits/channel and alpha. That's 256 GiB. I have 24 GiB RAM and 180 GiB swap. Of course it won't be enough. :) I have in the past worked with 32,768x32,768 images with reasonable responsiveness. With a height of 1 pixel, that would equal 1,073,741,824x1. You mention millions, so you should be safe. Especially since my computer is quite dated, so even if you should have less RAM that I do, yours is likely faster. $\endgroup$ – Duane Dibbley Aug 14 '18 at 0:51

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