Polygon2D Antialiasing Desktop<>Android

Nanites

Hi,

I'm using antialiased Polygon2Ds in my game, which (after some struggle with the settings) works on desktop, but on Android it seems to not work at all. I'm using GLES3, Framebuffer Allocation set to 2D for both desktop and mobile.

How can I get AA to work? For my game, I absolutely need it...

cybereality

OpenGL ES 2.0 works better on mobile. If you are publishing a game, you want 2.0 for the best compatibility (many older phones don't support 3.0 and even some newer ones have problems). In terms of AA, yes Frame Buffer Allocation on 2D should be the setting. I think also if you have an Environment node it needs to be set to Canvas.

Nanites

Thanks, I didn't know that - I thought GLES3 is the standard these days...

I tried to run my game with GLES2 but the AA behaviour did not change - are there settings I need to change?

Calinou

Polygon antialiasing relies on OpenGL line smoothing being available, and it's not mandated by either the GLES 2.0 or GLES 3.0 specification. This is why it won't work on Android/iOS which only have OpenGL ES, not OpenGL.

If you are using Line2D and want it to be antialiased, see this workaround: https://github.com/godotengine/godot-docs/issues/4441

Nanites

Thats a major problem for my game...

I already tried that workaround while experimenting with AA, but it doesnt work in my game as I need differently shaped Polygons, that touch each other at different angles - antialiasing along only one axis won't work.

Is there any other workaround or way to make it possible? Since my game absolutely rely on it.

cybereality

@Nanites said: I thought GLES3 is the standard these days... It is and should be well supported on newer phones. Definitely on higher end stuff it should be no problem. However, I have a lot of test devices and I've noticed on cheaper Android tablets, like the Kindle Fire or Lenovo Tab, even though they are only a few years old have major issues. It depends what you are doing. If it's a high end graphics game, those low-end devices won't play it anyhow so maybe GLES 3.0 would be worth it. However, then you might end up with bad reviews from people that buy the game and get a black screen or whatever. So you have to consider that.

Nanites

I'll be switching to GLES2 then. I did some testing and read on what is not supported and it's nothing I'm concerned about.

My game is a 2D puzzle with relatively simple graphics and only some particle effects and such (I use CPUParticles), the only thing GLES3 apparently does better is handling many lights - I use up do 30 lights in my levels so I'll have to test it on low end hardware.

The Antialiasing issue however seems to be a major one. Due to how my game works (geometric shapes that can touch each other and connect to one) it is absolutely vital to not have the jagged edges you get without AA.

cybereality

You might be able to fake AA with a blur post processing effect.

Nanites

Any tips on that? My polygons are of uniform color, so applying a blur shader as a material doesn't do anything. I might have to give them some texture probably...

Best solution would be to just blur the edges, but I have absolutely no idea how to accomplish that.

cybereality

It would be a fullscreen post-processing effect. If your game is all solid colors, you can do a fullscreen blur and that might work okay. Otherwise you'd have to detect the edges and then blur only those pixels. You can find a tutorial of how to do it here: https://docs.godotengine.org/en/stable/tutorials/viewports/custom_postprocessing.html#doc-custom-postprocessing

Nanites

Thank you. Looks like I'll finally will have to get into shaders and postprocessing...

I wonder if its possible to only blur detected edges that are on an angle, to keep the general sharpness as high as possible, but probably not since its individual pixel based?

cybereality

You could use something like FXAA. This shader should work. https://github.com/atomius0/Godot-3.1-FXAA-Shader

Calinou

@cybereality said: You could use something like FXAA. This shader should work. https://github.com/atomius0/Godot-3.1-FXAA-Shader

Since Godot 3.3, FXAA is a built-in feature in 3D. However, in 2D, you do not want to ever use FXAA due to the blurriness it adds (not even in 4K).

As a workaround for polygon antialiasing, you could draw several slightly offset polygons (between 2 and 8) with low opacity.

Nanites

I honestly think this should be a priority - right now the state of 2D Antialiasing in Godot is pretty poor, but it's such an important feature.

If I had the skills I'd already be working on implementing MSAA for 2D (that works on all platforms)... Sadly I'm not even near the ability to do so, but I hope someone else can - proper 2D AA is just an absolute requirement for a game engine.

Megalomaniak

To be frank, AA should only be needed for the vector elements such as mesh. Sprites might actually be negatively affected by it.

Nanites

I'm using Polygons with geometric shapes (puzzle game about moving them in the right places in the correct order) and when rotated, they look terrible without AA - this is probably not the most common thing, but also not extremely rare...

Megalomaniak

Yeah, as I said, makes sense for vector elements.