8k texture usage question

[demostenes]

I am thinking about using 8k textures as atlases for 4k and 2k textures (currently we are using 4k as maximum). For kit with for example 20x4k textures it would mean 5x8k and lowering number of materials, thus saving some drawcalls. Drawback is obvious, in case of using just one item from atlas, I am wasting memory and hdd load. But still there is lots of cases, where this makes sense (city from one kit....). I would like to ask, are there any other possible drawbacks caused by some internal engine mechanisms I am not aware of? Thanks!

Edited November 9, 2020 by demostenes

[silent]

Hi Jirka,

There is no difference how the engine handles the different textures inside. The only difference is the texture size. Streaming 8K textures from HDD is not a good idea, but if you targeting SSD only, that can work :)

Smaller textures are better for streaming (but not the tens of thousands of 256x256 ones). 

We used texture atlases in Superposition for newspapers, pencils and books (when you need to texture very similar objects, but also make them unique). Almost all the time you can see most of these objects at once in the camera frustum, so in that case using the atlases is appropriate. Not sure about the your use case and what kind of objects you are going to merge and reuse.

So, I would suggest to do some tests and see how it goes. Not always packing all the textures into the atlases will give you any improvements.

Thanks!

[demostenes]

We are already using altases, but recenty I was checking how some AAA games are done and they are atlasing everything. A LOT. Even various tiling textures (8 textures in 1k*8k atlas). It makes sense, if you have some town kit (walls, doors, wooden beams, etc), there is always majority of these objects in frustum. So there is no need to have 100 textures of various sizes, if you can fit all into 5 8k atlases. Performance gain is probably significant in such case. So only question is about how their engine handles streaming, to not unload/reload much, probably precache during world load a lot. We have to try, we definitelly target on SSD. Thanks!

Edited November 10, 2020 by demostenes