SSGI - Some considerations about "realism-effects"

[issimissimo]

PREMISE: Unfortunately I'm not good at all with shaders, so I'm just sharing and talking about 3rd parties work, and please excuse me if I'll not use the proper terms.

There's a very good effect for postprocessing that include SSGI, SSR, etc
https://github.com/0beqz/realism-effects

It work quite well in my opinion, but unfortunately it seem to be discontinued.
Actual major issues (always in my opinion):
1 - Quite poor quality with transparent materials
2 - Lack of support for ShadowMaterial
3 - The canvas loose its transparency (the SSGI effect create a "ssgiEffect.GBufferDebugPass.Texture" that indeed show the alpha of the image, but for unknown reasons to me it seem not be used)

I've breaked my mind to try to solve the 3rd one (lack of transparency on the canvas) for hours, but I didn't solve the problem.

Maybe someone much more skilled than me will be able to do that, and to improve this very nice effect.

If you want to give a try here are some basic instructions:
1 - download the files zipped from my link (I've just zipped the updated files, because the npm installed ones, from instructions of the author, do not work)
https://issimissimo.com/exp/realism-effects.zip
and put them somewhere (e.g. src/lib/realism-effects)

2 - if you use Vite put these lines:
resolve: {
alias: [
{ find: "realism-effects", replacement: "/src/lib/realism-effects/index.js" },

Many thanks!

[vanruesc]

https://github.com/0beqz/realism-effects

I agree. This is already included in the relevant tickets: #571, #599.

Quite poor quality with transparent materials

Could you please provide an example of this?

Lack of support for ShadowMaterial

Could you elaborate?

The canvas loose its transparency

This is often unavoidable with postprocessing effects - either because it's not technically possible or due to performance reasons. It's worth noting that not a single game out there uses the concept of a transparent canvas for those same reasons.

You can get some simpler overlay effects semi-working with a transparent canvas, but it's generally not recommended. Postprocessing does allow the use of alpha, but it can't guarantee correct results in that case.

[issimissimo]

Could you please provide an example of this?

It's easier to explain. SSGI actually doesn't support "trasmission" property, and using just "alpha" for transparency is not the best to create material like glass, that's why there's "MeshPhysicalMaterial.transmission"

Could you elaborate?

For application like product visualization, configurators, etc, it would be very useful to be able to cacth only the shadows (for example onto a plane), so to have a flat background (let's say white) and nice looking shadows on it
Unfortunately a 3D background is not an option, because it create too many artifacts when the camera move

More SSGI main issues (in my opinion)

• Doesn't work with lights
• Doesn't work with SSAO
• After a couple of mins that the camera don't move the render get jarged