Hello!
I am working in a mobile game and made some Ivy models which have around 100 textured quads. The Ivy model uses shader Mobile/Particles/Alpha Blended.
At any point around 4 of these models are visible (thus around 400 quads).
I have found some threads that warned using alpha blended quads on mobile kills performance. I did profile the performance on my iPhone 7 and the performance was ok (steady 60fps).
Unfortunately I do not have access to older mobile devices. So I would like to ask if around 400 alpha blended quads are ok in 2021 on mobile? Or will this still be a problem on older devices?
It’s not the number of them that is a problem, is how much they are overlapping and how big they are on the screen.
If it’s 400 overlapping full screen quads, then that’s way too many. In all other cases… Well it depends.
After having said that, the advice of being super extra careful with alpha blending was more relevant 7~ years ago or so. When we had the first couple generation of phones with much higher resolution screens (iPhone 4 and whatever equivalent Android were out at the time), they did have a lot more pixels they needed to draw, and barely enough fillrate to do it.
Having had released a game when the iPhone 4 was relevant, I would see PC / Console games of the time, and the thing I would be impressed by would be, “oh, wow, look at all those overlapping transparencies”.
You don’t need to be as careful these days.
The best advice I can give you is buy a semi-decent, kinda old android phone you want as a baseline, and use that to see if you have any performance issues.
I also think the iPhone 7 is not bad as a baseline for iPhones. I think an iPhone 6s is the baseline any new mobile game is expected to run well on and the iPhone 7 is one generation ahead of that.
Also the shader that it uses is just as important as how big each particle is. If it’s an expensive shader you can kiss all FPS goodbye.
Yes, agreed, my post was based on the OP saying he was using
which is really simple.
Use a more complicated shader than that on overlapping alpha blended stuff and things can get bad much faster.
Most mobile performance tips are for about the 10 years ago hardware