Any drawbacks to baking at 16 bit channel/format?

guitarguy00

Hey guys, when baking normal maps in marmoset I usually select the 16 bit format option(32 bit causes my old laptop to close Marmoset lol) as when I select 8 bit I notice some dithering after the bake. But I have heard that 16 bit format is not always the best way to go? Or is that when exporting out the texture maps out of Substance(choosing 8 bit PNG instead of 16)?? Any help would be very much appreciated as this is pretty important going forward. Thanks heaps.

Shuma

If your normal map will end in a game engine, it will be compressed anyway, so it doesn't matter that much

EarthQuake had made a cool post about Normal map and bit depth:
https://polycount.com/discussion/148303/of-bit-depths-banding-and-normal-maps

EarthQuake

So generally speaking you're not going to use 16 bit normal maps in a game engine. If you're working on something for your portfolio you can use 16 bit though, the only drawback is bigger file size and of course it takes up more vram (which may be an issue if you have a very complex scene).

If it's going into a game engine, it should be converted from 16 to 8 bit at some point and dithering is generally a good thing (see link above).

If you're going to be editing it in Photoshop or Painter, it's good to have the extra bit depth for the source content. This way the dithering can happen at the end of the chain rather than the start. Again though, using 16 bit source may result in larger files and significantly worse performance in painting apps.

guitarguy00

EarthQuake said:

So generally speaking you're not going to use 16 bit normal maps in a game engine. If you're working on something for your portfolio you can use 16 bit though, the only drawback is bigger file size and of course it takes up more vram (which may be an issue if you have a very complex scene).

If it's going into a game engine, it should be converted from 16 to 8 bit at some point and dithering is generally a good thing (see link above).

If you're going to be editing it in Photoshop or Painter, it's good to have the extra bit depth for the source content. This way the dithering can happen at the end of the chain rather than the start. Again though, using 16 bit source may result in larger files and significantly worse performance in painting apps.

Thanks for that. I checked out the thread above and have a better understanding of the topic. How does one convert from 16 to 8 bit? Is it as simple as exporting out the Substance Painter texture files as 8 bit PNGs or do I have to do it in Photoshop? Thanks heaps once again.

EarthQuake

I am not super familar with how Painter handles dithering, so you may need to look into that more yourself. I would imagine it's simply a matter of exporting an 8 bit file though.

In Photoshop, if you convert from 16 bit to 8 bit it will dither the image automatically.

guitarguy00

Thanks again. Just to be on the safe side I'll probably export out at 16 bit in Substance and convert it down in PS. From what I gather it is as simple as going Image, then Mode and then selecting 8 bit? Nothing else?

EarthQuake

Yes that is correct, you could do some quick tests to see if Painter is using dithering when exporting 8 bit too. If it's dithered you'll see a bit of noise, if not, a bit of stair stepping, generally speaking.

guitarguy00

Thanks again. I tried it and viewed it in Sketchfab and noticed the slight grain/dither effect. I'll stick to using 16bit for port folio pieces like you said but will downsample to 8bit for game Is there any way possible to avoid normal map compression that happens in sketchfab/game engine?