froyok

froyok, 10 hours ago

@GabeMoralesVR Hmm, this will be a last resort option to me because if I can pay the authors I wouldn't mind.

froyok, 21 days ago

Ha, figured out the issue ! I was actually expanding the alpha radius during my fill pass, which created those gaps.

So it's mostly working okay now, trying to adjust how I tweak the focus range to make it easier to play with (I like the idea of a start/stop positions).

froyok, 14 days ago

Finally !

Weeks (if not even months) or rework and I can finally render cubemaps.

Pretty happy about it, especially since the cubemap generation side of things took less than a day to write. My refactor worked out really well. :)

#gamedev #opengl #shader

Video showing a reflective sphere showing the scene around. In the video the fog settings are toggled on/off to show the dynamic update on the sphere.

froyok, 14 days ago

@ataylor Haha yeah, I can imagine. It adds quite a few constraints. I needed to rethink a lot of things. Doesn't help that this is my first real engine. 🤪

froyok, 10 days ago

"Ho yeah, I will just use cmgen from Filament to prefilter my cubemap for Radiance"

This was me two days ago.
But cmgen only output either a single ktx file or all the individual mips of a cubemap as separate files.

So now the fun part is figuring out how to stitch everything together to get a working dds file.

froyok, 10 days ago

The even funnier part: my framework cannot load dds cubemap file, only individual faces.

This means I need a tool allows me to write a dds with custom mips, so that I produce one file per face, with support for hdr files as input.

I found none. So I'm considering building something myself via my framework, but the best format I can see myself using is RG11B10.

Ideally I should use BC6h, but for that I need an encoder that allows custom mip and HDR files as input.

froyok, 10 days ago

I have been banging my head quite a bit the past two days.

I know I'm in corner case, but I'm once again astonished at the lack of good tooling out there for writing in this kind of format.

I would really like avoid writing my own DDS encoder, because I feel it's one of those rabbit holes it will be difficult to get out of. But it's starting to feel like I won't have a lot of options.

froyok, 10 days ago

Last silly idea I got: storing my RG11B10 cubemaps in RGBA8 with RGBM compression instead. That will require some on the fly decoding but that's might be tolerable.

froyok, 10 days ago

@shram86 It will happen at some point, it's the second time that I end-up facing a wall, but I just don't want to spend the time on it right now unfortunately. Hence my frustration. 😅

froyok, 10 days ago

@k_narkowicz Hooo, thx, this looks promising !

froyok, 8 days ago

Went with RG11B10 as expected to store my cubemap. Each mip as an individual file stored as a binary blob into a common zip file per probe.
Not the prettiest but it does the job for now. I don't have to deal with RGBM at least.

froyok, 8 days ago

Mipmap transitions are really nice now ! :D

A shiny ball alternating back and forth between a very shiny and a very rough surface.

froyok, 8 days ago

I also had to do the pbr balls test !
No that I only take care of radiance here. There is no IBL irradiance. I will see if I do something for it or not via cubemaps.

froyok, 8 days ago

here is what it looks like in my usual scene with the probe pushed in the back. Everything looks grayish because of the neon light in the background.

froyok, 8 days ago

I need to rethink how I manage my lights (once again) because right now the light casting shadows are rendered as additive light, which means the IBL contributions is applied several times.

Until now I didn't have a notion of "ambient" lighting.

froyok, 3 days ago

Working on my cubemap generation pipeline I was still puzzled on why the IBL would be so strong compared to the actual lights.

I decided to verify that my PBR wasn't broken by using red PBR balls this time and well...

froyok, 3 days ago

Took me a day to figure out what was happening.
After checking my code a few times I isolated it out on being related to the DFG LUT.

Inverting its value (one minus) was somehow fixing the shading and brightness issue. This was very confusing.

Then I extracted the LUT from Filament and compared it from Learn OpenGL and mine.

Here is what they look like in Designer:

froyok, 3 days ago

Notice what's wrong ?

Filament LUT use swapped Red and Green channels in its LUT.
My initial one minus trick was just a lucky fix. I'm glad I took the time to figure out what was happening.

In their doc, Filament doesn't mention that swap: https://google.github.io/filament/Filament.md.html#table_texturedfg

Anyway, once I figured this out, the fix was immediate and my shiny balls were now looking great:

froyok, 3 days ago

So once that was working, I quickly hacked in parallax correction for the cubemap and overriden Sponza floor to be mirror-like.

It now looks really great ! Time to clean up the code and expose everything on the editor side. :D

#gamedev #opengl #cubemap

A looping gif of a camera panning inside Intel's Sponza scene. The floor reflects the pillar and a neon light.

froyok, 3 days ago

@frguthmann That's the issue with scary math like that, I'm too afraid to read it properly. :p

froyok, 3 days ago

@nick It's pretty fresh and requires specific hardware I believe, it just got introduced in DX12 so I don't know about OpenGL and also my framework would need to support it too which isn't the case yet.
Anyway, BC6h is the ideal target here. :)

froyok, 1 day ago

I'm looking at ways to store my shadow volumes resulting binary mask in the form of a bit mask.

The goal is storing something like 32 shadows into an RGBA8 texture to sample it later when rendering object.

Doing so will allow me to render the lit object only once (while doing IBL + casting lights + other lights).

froyok, 1 day ago

But today I played again with the idea of mesh based light shafts.
I asked a colleague for help and it got me some convincing results !
This is basic depth evaluation, no analytical formula yet.

#gamedev #opengl #shadows