No Sprite3D support? No PixelGrid support?

bitsalive

Hey!
We've been a bit hesitant about using Spine for our game in Godot because of the required custom builds (will it work with consoles?)
Anyway, we decided we can live with that and give it a shot.

So now when testing Spine with Godot we found a couple off issues and I wonder if this will be adressed in the near future?

1) SpineSprites are only Node2D:
This is by far the biggest issue. Why not inherit from Sprite3D as well?
(PS: found a workaround in a forum, but this just gotta be supported natively with properties from Sprite3D)

2) You added the cool "Pixel grid" function to Spine:
...for working with pixelart games -> doesn't work in Godot. Are you missing a custom shader/material or something?

3) Lower FPS for animations?
We need animations to only play in 12fps due to a retro feel - looks like there is no option for that in Godot?

We really would like to use Spine for our project, since it's awesome!
But this is just stuff we'd need - are there any estimations when this might work?

Thanks for the reply!

Harald

bitsalive 2) You added the cool "Pixel grid" function to Spine:
...for working with pixelart games -> doesn't work in Godot. Are you missing a custom shader/material or something?

Please note that Pixelgrid is a viewport rendering option of the Spine Editor only (like Smoothing):
"When checked, the viewport rendering is rasterized to simulate pixel art."
It is not a setting which is exported with the skeleton, or which any of the Spine runtimes supports directly.

Spinebot

SpineSprites are only Node2D:
Currently, the SpineSprite node in the spine-godot runtime is designed to work with 2D scenes and inherits from Node2D. There is no native support for Sprite3D at this time. However, you can use a workaround by creating a custom node that handles 3D transformations and rendering. This involves manually updating the SpineSprite's position and rotation to match a 3D node's transform.
Pixel Grid Function:
The "Pixel grid" function in Spine is not directly supported in Godot through the spine-godot runtime. This feature would require a custom shader or material to replicate the pixel grid effect. You can create a custom shader in Godot to achieve this effect by snapping the positions of the vertices to a pixel grid.
Lower FPS for Animations:
To achieve a lower frame rate for animations, such as 12fps, you can manually control the update rate of the SpineSprite. Set the Update Mode to Manual and update the skeleton at your desired frame rate by calling SpineSprite.update_skeleton() in a custom _process(delta) function. This allows you to control the exact timing of the animation updates.

extends SpineSprite

var frame_time = 1.0 / 12.0  # 12 fps
var accumulator = 0.0

func _process(delta):
    accumulator += delta
    if accumulator >= frame_time:
        update_skeleton()
        accumulator -= frame_time

These features are not currently supported natively in the spine-godot runtime, and there is no official timeline for their implementation. However, the provided workarounds should help you achieve the desired functionality in your project.

bitsalive

Alright! Thanks for the fast reply!

Do you think Sprite3D will be supported in an upcoming version out-of-the-box?
Is there any ETA for that or is it even on the timeline?

Thanks in advance!

Harald

@bitsalive See this issue ticket:
EsotericSoftware/spine-runtimes2135

You can check out the road map here:
http://esotericsoftware.com/spine-roadmap

Harald

@bitsalive You might also find related forum threads with additional info like this one:
https://esotericsoftware.com/forum/d/23907-is-it-possible-to-use-spine2d-in-the-godot-3d-scene

bitsalive

Thank you @Harald !
This was really helpful!

I'm gonna give it a try and see how far I can get with the 3D workaround suggested in the Github Thread.
I'll also check if i can re-create the Pixel Grid as shader.
In case somebody already got something like this running, any link or help is appreciated!

One last thing though:
When using a custom build of Godot - do you think it will work with releases for consoles? Some companies offer additional source code for console builds, so where does the Spine build fit in there?

Thank you and happy weekend!

bitsalive

Oh! And another quick question...
You don't happen to know what algorithm the Pixel Grid viewport feature uses?
I got the pixelation shader working, but to reproduce the exact same thing it would be helpful to know how it's done in Spine (like average, median, mosaic and whatnot...)

Nate

Spine's pixel grid first renders the skeleton to a buffer at full resolution, then renders the buffer using the viewport camera. This causes rasterization to happen when rendering to the buffer. For example, when an image is rotated and you draw it scaled up, you'll see the pixels are rotated. By drawing it to the buffer first, the buffer is scaled up and the buffer's pixels are larger but not rotated.

(I'll have to let our other staff field your Godot questions! They are likely enjoying their weekend and will respond Monday.)

bitsalive

Hi @Nate !
Thanks for clarifying! So to get the correct rasterization you need to know the input size of the original image, is that correct?

In order to write a shader in Godot that does that I then need to get the size of the SpineSprite and pass it to the shader, I guess?
Did anybody try that out already?

Thanks for answering the questions! Really good support!
Looking forward to the Godot-staff answers! Thanks and have a good week!

Nate

bitsalive So to get the correct rasterization you need to know the input size of the original image, is that correct?

Spine uses a 2048x2048 buffer. If your skeleton is larger than that (at 100% zoom), it will be cut off. You can see this in the editor by moving part of your skeleton far away with pixel grid enabled.

Mario

I'm not aware of anyone trying to reproduce the editor pixel grid functionality in Godot. You can get the bounding box of the skeleton in its coordinate system via SpineSprite.get_skeleton().get_bounds(). Depending on your scene hierarchy, you might have to transform those bounds further, i.e. by the SpineSprite and anything else that may modify the on-screen location of the sprite, like a camera system. That's not something we can anticipate or cover via our API.

As for consoles, I'm working on turning spine-godot into an extension. W4 Games has indicated interest in that with regards to consoles as well, so there's a clear path forward plus safety for businesses targeting consoles with Godot via W4 Games. We ourselves do not have access to any console SDKs, so we won't be able to give support for that.

bitsalive

Hi @Mario
Thanks for the update!
When you say you're working to turn it into an extension, do you mean like an addon that works with the default version of Godot (so no custom build required?)
Great to hear that W4 is interested!

Is there any ETA for the extension?
And... any love for Sprite3D/SpineSprite3d? :-)

Mario

When you say you're working to turn it into an extension, do you mean like an addon that works with the default version of Godot (so no custom build required?)

Yes, as a GDExtension.

Is there any ETA for the extension?

When it's done 🙂 Sadly, it's a ton of work to switch over to GDExtension, as the API is incompatible with the Godot module API.

And... any love for Sprite3D/SpineSprite3d? :-)

When the conversion to a GDExtension is done.

bitsalive

Mario
Oh - i just saw your response!
This is AWESOME! Can't wait for the GDExtension! Thanks for working on this!

Mario

The extension is complete, with two caveats: no support for AnimationPlayer, and specifying animation mixes in the inspector can't be done as nicely as with our custom Godot build. Other than that it's fully functional.

I still have to fix up the automated builds so we also publish binaries for all platforms. Once its ready, we'll post on the blog, on here on the forum, and send out an email.

Our you subscribe to the issue here:
EsotericSoftware/spine-runtimes2651

bitsalive

Mario
Wow, that was fast! Very good news! Thank you!

When you say, no support for AnimationPlayer- do you mean the ability to use Godot AnimationPlayer Editor when creating the Spine Animation Track, mentioned here in the docs:
https://en.esotericsoftware.com/spine-godot#SpineAnimationTrack

Are animation mixes working in general? Just not as comfy as in the build version?

Also, is a Sprite3D Version supported yet?
I used the workaround posted somewhere in the forum and it worked pretty well.

And last one:
Is there a version to download somewhere? Maybe i just didn't find it. Or do we wait for the automated builds?

Lots of questions :-) But I'm super excited you got this working so quick! Really good job!

Mario

When you say, no support for AnimationPlayer- do you mean the ability to use Godot AnimationPlayer Editor when creating the Spine Animation Track, mentioned here in the docs:
https://en.esotericsoftware.com/spine-godot#SpineAnimationTrack

Exactly. No support for Spine Animation Track in the GDExtension version of spine-godot

Are animation mixes working in general? Just not as comfy as in the build version?

Yes, they work either in the inspector by filling in the general purpose array UI (which is super uncomfortable), or via a script attached to your node that sets them on node initialization via the standard Spine API.

Also, is a Sprite3D Version supported yet?

Nope, that will come once I have finished the next point.

Is there a version to download somewhere? Maybe i just didn't find it. Or do we wait for the automated builds?

I'm currently working on setting up the automated builds. You can compile it yourself from source by:

git clone https://github.com/esotericsoftware/spine-runtimes
cd spine-runtimes/spine-godot
./build/setup-extension.sh 4.3-stable true
scons target=editor

This will clone the Spine Runtimes, setup everything so the extension can be build, and finally invokes SCons to build the extension for the platform you are on. The resulting binary will beplaced in examples-v4-extension/bin, along with the spine_godot_extension.gdextension file, which tells Godot where to find the shared libraries for the extension for each platform.

I've only tested on macOS so far, and only editor builds. YMMV. That's why we'll provide automated builds 🙂

One more caveat: it's currently not possible to generate nice, idiomatic C# bindings for GDExtensions. Instead, you'll have to go through the ClassDB and Object APIs provided by Godot. It's basically string-based, untyped, reflection.