[Go] HDR-less bloom ?

This probably applies to all kinds of post processes? It would be really nice if we are able to do some tone mapping on the final frames. Right now this requires a lot of extra work, and unfortunately, because Unreal for GO/GearVR  requires u to work in LDR, it ends up looking rather bad. 

moulder6 said:

Right now this requires a lot of extra work, and unfortunately, because Unreal for GO/GearVR  requires u to work in LDR, it ends up looking rather bad. 

I can assure you that bloom looks good in LDR, at least on PC.

motorsep said:

moulder6 said:

Right now this requires a lot of extra work, and unfortunately, because Unreal for GO/GearVR  requires u to work in LDR, it ends up looking rather bad. 

I can assure you that bloom looks good in LDR, at least on PC.

The output for all but the newest monitors/TVs is LDR, anyway. The problem is that the results of color operations is different when the calculations are made in HDR vs. LDR space. Still, having some way to do post processing (including bloom), would be better than having no way to do any. 

Any kind of fullscreen blur pass on mobile is fantastically expensive, requiring full pipeline flushes and juggling of memory. That is because the GPU throws away parts of the back buffer that it is done with, one tile at a time, and doing a blur requires reading from tiles that you no longer have access to and must be copied back from system memory.

Post process in general can actually be cheaper on mobile than on PC, as long as the effect only reads from the same pixel that it writes to it is no more expensive than drawing with alpha blending and doesn't need any synchronization. 

Hey @motorsep did you able to get bloom effect without enabling mobile HDR ? i can't find documentation mentioning bloom require mobile HDR or not.

Mohammed_hashim said:

Hey @motorsep did you able to get bloom effect without enabling mobile HDR ? i can't find documentation mentioning bloom require mobile HDR or not.

There is no docs for that. Changes have to be made to engine's rendering code (and shaders). That being said, no solution is available.

motorsep said:

Mohammed_hashim said:

Hey @motorsep did you able to get bloom effect without enabling mobile HDR ? i can't find documentation mentioning bloom require mobile HDR or not.

There is no docs for that. Changes have to be made to engine's rendering code (and shaders). That being said, no solution is available.

Oh i see thanks for the answer, seems we are doomed with UE4, my game heavily depends on bloom even game mechanic and now it looks so dull without it. i only wish i could get a cheap bloom. whats the point of mobile HDR if we can't use it on modern mobile with acceptably performance.
I made a quick test HDR on with only bloom in empty level and i got 40 fps with galaxy s7 edge so it seems its out of question.
I heard old UE4 <4.10 had good performance on HDR mobile but whats the point if Oculus won't accept your app unless its made with latest version of UE4. I remember Epic changed their post process in 4.15 with film Tonemapper feature so i will try to make a quick test and see if i could get performance with old post process just for testing for now. 
Edit: nah looks like r.TonemapperFilm already disabled by default on mobile so those horrible performance is already without TonemapperFilm.

Yep MobileVR hardware is still not good enough for mobile HDR projects
You can make some fake bloom effects using transparent/additive material sprites depending on your project - doesn't look as good of course but can be a 'cheap' workaround

aussieburgerVR said:

Yep MobileVR hardware is still not good enough for mobile HDR projects
You can make some fake bloom effects using transparent/additive material sprites depending on your project - doesn't look as good of course but can be a 'cheap' workaround

Since the elements that glow on my game is movables and its a lot I doubt I could do that without huge performance loss. but that's a great idea I will try it later and see if I could make it work.