froyok

froyok OP , 1 month ago

Currently writing a Python script to auto-kill it before it slows down the machine and relaunch it.

I guess I could also put it into the sleep schedule. 🤔

froyok OP , 4 months ago

Alright, got it working at both end, depending on a switch. So I was able to compare.

On regular geometry edges, visually almost no differences.

BUT, doing FXAA as the last step end produce noticeable differences because it misses aliasing that has been exaggerated by some effects.

Example with my chromatic aberration effect:

froyok OP , 3 months ago

Yesterday I tried once again to optimize my SSAO pass in compute, and still failed. A fragment shader still performs quite a lot better.

So today I decided to play again with my bloom and lens-flare to tinker with other ideas. Like anamorphic shapes.

Not necessarily a success, but I got interesting results just by playing with some buffers size or UVs:

Screenshot of my game engine showing a bright cube partially hidden by a pillar emitting a bright vertical streak of light and curved lens-flares.

froyok OP , 3 months ago

Back on Ombre... and I decided to play again with lens-flares (I know 🤪 ).

This time I wanted to try out the little radial projection trick from John Chapman article (https://john-chapman.github.io/2017/11/05/pseudo-lens-flare.html) to create fake streaks. It's a good start, but I will need to think about how to refine that effect. It looks nice already !

Video of a camera moving around making a point light reflecting on a cube shine and creating lens-flares.

froyok OP , 2 months ago

Been tweaking my lens-flare again for the past few days and now reaching a point where I want to try some kind of anamorphic bloom.

Right now I went with a hack where I modify one of the downsample texture when it is fed for the upsample pass. It is giving me a rough idea of what to expect, but it's not good enough yet (not sharp enough, and some flickering issue to manage still).

Will likely need to do a proper downsample/upsample process too.

#gamedev #shader #postprocess #bloom

A screenshot of my game engine showing a bright white neon behind a pillar emitting a vertical light streak.

froyok OP , 2 months ago

I tweaked a bit more and properly integrated my bloom streak pass in the engine.

Combined with the regular bloom and the lens-flare this is all coming together well ! :)

Screenshot of my engine showing a neon light below an arch glowing up vertically behind a column.
Screenshot of my engine showing a point light above a cube reflecting as a vertical line.

froyok OP , 2 months ago

I couldn't stop at two bloom passes, so I added a third one to fake atmospheric scattering.

So... how much humidity do you want in the air ? 😄

It is based on: https://github.com/OCASM/SSMS
(But I'm planning on improving some things.)

#gamedev #shader #fog

Screenshot of my game engine showing a new fog effect that blurs the image based on a distance in a scene with arches and pillars.
Screenshot of my game engine showing a new fog effect that blurs the image based on a distance in a scene with arches and pillars.

froyok OP , 2 months ago

I tweaked a bit further that fog blur and plugged in my fog function in it.
This way I can also use it to emulate height fog with it too. :)

froyok OP , 2 months ago

This morning I also quickly tried to add some fake halation effect (light bleeding into darker areas).

It's basically a highpass filter using the bloom downsamples and the current scene color texture, and then isolating the bright parts to make them bleed into the dark areas.

Currently it's an additive blend done with the HDR color, so it adds light. It low enough to no matter too much. Maybe I should use a lerp too to be more energy preserving ?

Screenshot of my game engine showing a bright white light glowing behind a pillar.

froyok OP , 2 months ago

Woops, I had a Saturate() in there when setting up the highpass. Now I get why my halation edges where so sharp ! 🙃

Also switched to a combination of mix/lerp for blending and it works as good as before. So no additional energy yeay !

froyok OP , 2 months ago

Turns out the Love framework had a bug for a few months and wasn't loading sRGB texture properly.
Got fixed today after my report, so now colors match properly:

froyok OP , 2 months ago

I didn't notice it until today, because I decided to draw a texture straight to the screen for a temporary loading screen.

All fixed, so it looks like this now:

froyok OP , 2 months ago

My current struggle.

I'm already doing the firefly attenuation based on Jimenez slides.

I'm trying to think about possible solutions:

• Clamping max brightness ?
• Reducing emissive intensity based on distance ?
• Doing some temporal stabilization (like TAA but only for bloom/fog downsample) ?

I'm open to suggestions.

A video of my game engine showing a camera moving forward toward a neon light. The light flickers as the camera move.

froyok OP , 2 months ago

I gave a try at clamping (like @EeroMutka suggested) but as I expected, because I use a non-thresholded and energy preserving bloom method, clamping kills off the HDR range and bloom becomes non-existent.

Here is with and without clamping:

Screenshot a my game engine showing a white neon light. Clamping is disabled and a wide halo/veil is visible around the light.

froyok OP , 2 months ago

The current idea I wanna try is doing a copy of the first downsample (full or smaller res) and blend it into the next frame downsample. Just to see if it helps with the spatial/temporal aliasing.
Will figure out ghosting issues afterward if it becomes promising.

froyok OP , 2 months ago

Weeeee !

Video of a camera looking around a neon light. Streaks follow the light while moving.

froyok OP , 2 months ago

First of all, this is very framerate dependent when using a fixed blend value.

Secondly, you need to weight the previous a lot to make the flicker not visible/disturbing, favoring a lot of ghosting.

Right now it's a stupid blend, so I wonder if re-projection would help a lot now. 🤔

froyok OP , 2 months ago

Previous frame reprojection seems to be doing the trick !
(Combined with color clamping to hide disocclusion.)

Here is a comparison with off (blend at 1) and on (blend at 0.1). Flickering is almost gone and no ghosting seems to be visible.

Video of my game engine showing temporal blending of the Fog blur off vs on to hide flickering from bright emissive source.

froyok OP , 2 months ago

It's basically TAA but on a blurry and half-resolution buffer.

So preserving details doesn't really matter. I don't even bother with jittering.

Transparency/emissive surface not writing into the depth buffer don't seem to suffer either. That's really cool because I was afraid of that !

froyok OP , 2 months ago

This week I continued with my fog stuff and added local volumes of analytical fog.

It's going to be quite useful to make moody effects in scenes.

So far I got Sphere and Box shape working, but I'm thinking about doing cones (for spotlights) and maybe cylinders (for dirty liquids container or holograms).

#gamedev #screenshotsaturday #shader #fog

Screenshot of my game engine showing the Sponza scene with a beam of light/fog passing through.

froyok OP , 2 months ago

Combined with the screen space fog blur it can give some really neat results:

#gamedev #screenshotsaturday #fog #shader

froyok OP , 1 month ago

The past few days I have been looking into optimizing the bloom downsamples, see if I could merge down into one texture and do it in one pass.

Writing compute shader is hard, I made some progress but I haven't reached my goal yet.

I'm shelving the idea for now and will go back to it at some point.

froyok OP , 1 month ago

Instead I decided to finally look into rendering cubemaps.

Currently I'm not writing any code much, I'm trying to evaluate all my needs to properly build the architecture.

So far I only renderer a single point of view: the main camera. Cubemap introduce additional ones, and later I will have Portals too. So there are some rework needed in how I manage my rendering loop.

froyok OP , 1 month ago

Quite a few days later and the refactoring is almost done. The engine is rendering again and this time in a more contained way, so I should be able to render cubemaps soon ! :D

I even made a neat image of my engine layout now:

froyok OP , 1 month ago

With the post-process chain now working again, I thought I could try to add a depth of fieldpass as well, re-using some of the recent bokeh shader I used for my lens-flares.

It didn't go as planned, but it made some nice colors at least ! :D

froyok OP , 1 month ago

I was able to get this far... using a separable filter (with Brisebois2011 method).

However I can't seem to find a good way to avoid foreground pixels to bleed into the background even when only computing the background blur.

So I decided to switch towards another method instead. That's really too bad because I really liked the simplicity of it.

froyok OP , 1 month ago

Here is an example of the bleeding. I used pre-multiplied CoC but it's not enough and any kind of pixel rejection breaks the separable nature of the blur.

Here the bright lights are visible behind the limit of the character silhouette, showing the bleed into the foreground.

Video showing the camera moving back and forth, showing the artifact.

froyok OP , 1 month ago

I'm currently looking at the Scatter & Gather approach, but I wonder if anybody tried an hybrid method. Like using S&G for small bokeh and sprites for large bokeh ? Or maybe using S&G for far DOF and sprites for near DOF ?

I wonder at which points sprites could help performance, but because large ones cause overdraw. 🤔

Slide named "depth of field, a plausible and efficient dof reconstruction filter" from the presentation "Graphics games from CryEngine 3".

froyok OP , 1 month ago

Progress !

Got Crytek kernel computation working, very fun to tweak on the fly ! (Generated CPU side then sent to the shader as a buffer of sampling positions.)

Focus range isn't yet working, that's the nest step.

A video showcasing the depth of field settings available in my engine. Tweaked the parameters changes the shape of the bokeh.

froyok OP , 28 days ago

A few days have passed and I finally got most of the DOF post-process working !
My hexagonal bokeh works well and is relatively cheap. I even got some nice additional effects like chromatic aberration on the bokeh itself.

froyok OP , 28 days ago

The effect is done at half-resolution, I haven't figured out yet a good way to blend in back to the main image so there is a slight bleed of colors.

froyok OP , 28 days ago

Example of the chromatic aberration on the bokeh:

froyok OP , 28 days ago

The last detail I'm trying to figure out is how to properly fade the center of the bokeh pattern to make "holes" in the shape.
I have already something working, but it's not perfect yet:

image/png

froyok OP , 28 days ago

Bonus: for fun I'm trying to do an heart shaped bokeh.
First results are quite funny, but not really useful. 😅
(I currently rethinking how I should distributes the sample to fill the shape.)

image/png

froyok OP , 26 days ago

I got an heart-like bokeh shape working ! 😄

froyok OP , 12 days ago

I didn't make a lot of progress the pas few days, thx to Helldivers 2.

I managed to try out some optimization tricks this week however to improve my shadow volumes. One worked, the other didn't.

froyok OP , 12 days ago

I tried to use a custom projection matrix with different clip planes to constrain the rendering to the light volume.

I even went with masking the depth buffer by the light radius to help discarding triangles/fragments via the depth test.

It didn't improve performance, it even made things slower on my old laptop. 😩

froyok OP , 12 days ago

Like when I used the depth bounds extension at the time, this tricks had almost no impact and I presume the extra cost was coming from the depth buffer copy stuff.

So this is making me think that performance improvement will only come with smarter geometry setup.

I think I need to look in ways to subdivide the geometry but in a less taking way during the compute pass.

froyok OP , 12 days ago

The optimization that actually worked meanwhile was the fact I was launching threads during my compute dispatch just to discard them afterward in the shader code.

Now instead I launch exactly the number I need and compute a better index for processing my geometry.

So just helping the GPU schedule things better gave me 0.04ms saving on around 140K meshes (went from 0.1ms to 0.065ms). That's on my beefy GPU, I presume on my old laptop this will be even better.

froyok OP , 12 days ago

@GabeMoralesVR I'm thinking of Portals for culling yeah, either in an automated way or hand-authored. It's something I would like to tackle this year.
No plans with ECS system/design for now, will see if I need it when I will start to scale things up.
And if you are curious, for Physics I plan to integrate an engine (likely ODE or Jolt).

froyok OP , 12 days ago

@GabeMoralesVR For sure ! :)

froyok OP , 12 days ago

Confirmed: went from 0.6 to 0.22ms on my laptop in the same scenario ! :D

froyok OP , 8 days ago

Back on my DOF, because I'm not happy with this upscale pass. 💀

froyok OP , 8 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 OP , 1 day 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 OP , 1 day 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. 🤪