←back to thread

Shipping textures as PNGs is suboptimal

(gamesbymason.com)
148 points ibobev | 1 comments | 06 Sep 25 20:37 UTC | HN request time: 0.203s | source
Show context
Stevvo ◴[06 Sep 25 22:11 UTC] No.45153352[source]▶
Any modern engine does this automatically on PNG import, or as part of material/shader setup. You want different formats for different things, e.g AO, normals, bcs different formats have different compression artifacts.
replies(1): >>45153957 #
pimlottc ◴[06 Sep 25 23:50 UTC] No.45153957[source]▶
How much extra time does it add for startup? For a single texture it’s probably negotiable but for a modern game, we’re talking about thousands of textures, so maybe it adds up?
replies(4): >>45154071 #>>45154958 #>>45155944 #>>45157033 #
midnightclubbed ◴[07 Sep 25 02:49 UTC] No.45154958[source]▶
If you’re compressing at load-time it can be a lot. You can do a quick and dirty compress to BC1-3 (assuming you are on PC) in a few tens of milliseconds but quality will be suboptimal, higher quality will likely take a few seconds per texture and going to BC6 takes even longer but will look much better.
replies(1): >>45155440 #
Dylan16807 ◴[07 Sep 25 04:38 UTC] No.45155440[source]▶
> higher quality will likely take a few seconds per texture

It takes that long to do a good compression on the format that interpolates 2 colors for each 4x4 block? Huh.

replies(3): >>45156036 #>>45157983 #>>45165972 #
1. midnightclubbed ◴[07 Sep 25 07:05 UTC] No.45156036[source]▶
It’s not entirely trivial (if you care about texture quality) you’re choosing 2 endpoints in 3d space that can be linearly interpolated to values that best fit 16 points in 3d space.

I may have been a little off with saying seconds per texture but it’s definitely non trivial amounts of time. And ects (mobile) and BC7 are certainly still not something you want to compress to at game load-time.

Some comparisons of texture compression speeds for various formats (from 2020 but on a 12core i9): https://www.aras-p.info/blog/2020/12/08/Texture-Compression-...