HD/SD Assets and Asset Bundle Issues

seraphki

Hello everyone!

I've got a couple issues I'm facing, and I'm hoping someone here can point a simple solution. Cause that's the dream, right?

Problem 1: a simple way to switch between HD and SD assets.
A note on my implementation: the methods I'm implementing do the actual "swapping" at runtime instead of a script that swaps things out during editing because I'm using asset bundles, so I need to point to a new location at runtime anyway, I just point to the proper variant.

Method 1. Resizing the texture spine generates in photoshop, and switching out the material's texture on runtime based on set quality level. The problem with this is, every time I export a resize, I get weird white artifacts in the texture, even after the same import settings are applied. If I get a spine export that is half scale, the sprites always seem to repackage in a different order so they need a new atlas.

Method 2. Using different Atlas Assets and switching them out in the Skeleton Data
The other method was getting two exports from spine - one at half resolution, and switching them out in the Atlas Asset field in the skeleton data at runtime (based on resolution choice). Unfortunately, since these themselves are assets, any changes you make at runtime serialize and stay that way. Since I'm using Asset Bundles, that means that I have to deal with broken characters after every test run.

Method 3. Using different Skeleton Datas and switching them out on the characters at runtime
The last method I've been toying with is to switch out the entire skeleton data at runtime. I do have to delete the skeleton and regenerate everything, but I'm hoping its not too heavy a process. This seems to mostly work, and is my current fallback.

I can probably make something from one of the above methods work, but I'd love any advice if someone has a simpler way.

Problem 2: Asset Bundles.

Using method #3, I put all of the skeleton datas into asset bundles (same name, different variant). Since unity 5 it automatically collects dependencies, but I threw them all in there manually anyway (after it failed the first time). Unfortunately, when I run the project, all the textures are pink. The characters load, and they seem to animate (their little pink boxy arms flail about) but there's no image. I've read in a couple other posts that Unity might have an issue tracking down dependencies and re-linking them in Scriptable Objects (which I guess the Atlas files are), but I don't know if this is the issue. I've read that a couple people have gotten it to successfully work if they throw an entire prefab into an asset bundle, but our pipeline as it stands would require quite a bit of re-wiring to work with prefabs like that, so I'd rather avoid it if possible.

Hope someone has some advice they could lend me!
Thanks for reading =)

Cheers~

Pharan

We've discussed Method 1 a bit over email. I'm glad you got your forum account working!

A variant on Method 1 is using a non-pma shader like Unity's Sprite/Default shader. You would need to re-export your atlas without premultiply alpha.
More on that here, and the familiar white artifacts (bleed) that you're seeing. (Photoshop applies that automatically.) : Premultiply Alpha

Switching shaders and image encoding will allow you to use Method 1.
The singular practical drawback would be that you couldn't use the "additive" checkbox in Spine editor and benefit from batching of normal and additive parts. If you don't care about that optimization, I think this is totally the way to go.

Method 2 is a bit more tricky than just switching out atlas references in SkeletonDataAssets.

One question is, are you doing the swapping "on the fly" or is it a swap that you only intend to happen at loadtime?

The "on the fly" implementation is tricky (The team is also curious what you would need on-the-fly behavior for).
If you only need to switch the atlases at loadtime, you could easily create a SkeletonDataAsset at runtime instead of as a serialized asset, then assign that to the scene object or prefab.
As long as you have the references to the json/binary, the material and the AtlasAsset, it's trivial to assign them to a runtime-instantiated SkeletonDataAsset and let it load from there.

Just from trying AssetBundles, there seems to be an innumerable number of ways to bundle assets and it varies so much depending on each project: do you bundle just the textures? The .png and .atlas.txt? With the material? The AtlasAsset itself? The whole prefab and dependencies? All should work in theory but users have had various combinations break.
It hasn't helped me figure things out that they're a mess to work with (at least, that's what I gleaned from trying it, and from reading about people complaining about the same.)

But as long as Unity eventually gives you the correct references for all the necessary assets, you can always explicitly reassign all the correct fields at runtime and force-reload.

seraphki

So I'm not switching it on the fly, just once at runtime. Doing so because you use scripts to reference atlases in Asset Bundles. =)

I'll look into that pre-multiply alpha and see whats up. Though I don't actually handle spine so if I can mess with some solutions without having to get someone to re-export some things from spine. I do care about optimization though, since we're pushing texture resolutions as far as we can take them.

So what you're suggesting (building the skeletondataasset at runtime) is similar to the #3 method I've been using, and what I'll probably end up going with. I didn't even think to build it from scratch, I was including them in the Asset Databases and referencing them directly. Maybe it'll work better if I build it.

I first tried just adding the skeleton data asset (unity should add all dependencies automatically) but when that didn't work, I added all the pieces. I think they're all getting in there, it's just a linking issue. But I might be able to construct the whole thing from scratch, I guess I just wanted to make sure I wasn't going through that when I didn't have to. =)

Pharan

Ah, so it's a load time thing.
Actually, since you only need to swap out the AtlasAsset reference, you may only need to reassign (just to ensure you undo weird AssetBundle quirks) the fields on your existing SkeletonDataAssets. That would be better for you if you're actually using prefabs or have scenes that have Spine GameObjects in them.

The make-sure-you-load-correctly methods probably look something like this:


public static void ReloadAsset (AtlasAsset atlasAsset, TextAsset atlasFile, Material[] materials) {
     atlasAsset.Reset(); // Orphan previously generated data objects if they existed from a previous attempt at loading. Just for good measure.
     atlasAsset.atlasFile = atlasFile; // Stuff those correct references in there.
     atlasAsset.materials = materials; // Stuff those correct references in there.
     atlasAsset.GetAtlas(); // Try deserializing new data objects using the atlas text file and the materials.
}

public static void ReloadAsset (SkeletonDataAsset skeletonDataAsset, AtlasAsset[] atlasAssets) {
     skeletonDataAsset.Reset(); // Orphan previously generated data objects if they existed from a previous attempt at loading. Just for good measure.
     skeletonDataAsset.atlasAssets = atlasAssets; // Stuff those correct references in there.
     skeletonDataAsset.GetSkeletonData(false);  // Try deserializing new data objects using the json and atlas asset.
}

seraphki

Thanks for the info!
Most people in this situation seem to be using prefabs, but the way our situation is set up (our levels are all one big prefab and nested prefabs aren't really a thing) makes that more difficult. Also, since I'm using assets that are stored in asset bundles, I have to do something in the script anyway to point the scripts at the bundled assets, so I might as well do what I originally wanted to do, without the use of prefabs.
I was eventually able to pull it off.

Something that would have been (and would still be, in case you guys make updates) very helpful is a script that does the same thing your guys' import script does (taking textures, atlas, and json and creating materials, skeleton data, and atlas asset) but instead of creating asset files, you just return the assembled skeleton data. No asset files created, everything in memory. Essentially, tahts what I ended up doing.

Some problems I encountered doing this, just in case someone else had some of the same issues (or in case you have a better way to solve them):

#1. Scriptable Objects and Asset Bundles apparently don't place nice.
It would have been a lot easier if I could have just added an HD and SD skeleton data into asset bundles with different variants, but it would seem that they don't collect and re-link dependencies properly. I looked around for a solution, but it seems this is a known problem, I couldn't find a solution. If I manually included all the linked asset, it didn't seem to be able to find them. I even forced 'Collect Dependencies' in my asset build script (even though thats apparently default) and it didn't work. My solution was to just build the two scriptable objects (Atlas Asset and Skeleton Data Asset) from scratch.

#2. Things with the same name, but different extension
Spine exports things to have the same name, but different extensions. When you're loading things from an asset bundle, you only use its name, not its extension. I don't know why. Anyway, this meant I couldn't differenciate between the different assets. My solution was to add them to smaller asset bundles grouped by file type, and access them from there.

#3. Issues getting the Asset Text Asset from asset bundles
I suspect it's because of the .asset in its name (since you don't use extensions, there might be an issue with the '.') but for whatever reason, it kept not being able to load the Asset text files. Since I was grouping my bundles by level and asset type, my "atlas text file" bundle was pretty small, so the solution was just to load all of them and then find one with a matching name. I need to investivate this more later, but for now the fix works.

#4. Material Naming
If you have one texture for your spine character (called Character), the import process will create a predictable material called Character_Material. If there are two textures (Character and Character2) it will less predictably name the materials Character_Character and Character_Character2 instead of Character_Material and Character_Material2, as I suspected they would be. I just ended up creating new materials since I could more easily predict the name of the textures, but just FYI.

#5. Issues with 'fromAnimation'
After everything was assembled, I was getting an error in the GetSkeletonData method about fromAnimation being null. I tracked down that in the IngestSpineProject method, called from that import process I assume, fromAnimation and toAnimation were intialized as empty string arrays. As soon as I added that into my code after setting the atlas asset and json, things started working properly.

Anyway, as complicated as the process seemed, I think it best suits my need.
If you guys ever decide to implement a method for creating those assets via script, please let me know. I'd love it.

PS your forum kicks people out way too fast. I lost this post twice cause by the time I submitted it was like 'oops gotta log in'. :giggle: Guess its a good way to kick verbose buttface like myself.

Cheers! :beer:

Pharan

Yeah, I've had that log-out problem a few times before. It acts weird sometimes. Haven't had it happen recently though.

Let me read the rest of your post. Looks like juicy, definitive info. Give me a moment. : P

29 Aug 2016 3:41 pm

seraphki wrote
If you guys ever decide to implement a method for creating those assets via script, please let me know. I'd love it.

If you're looking for runtime code, it would look like this:
https://gist.github.com/pharan/77921a3f34b2925154b22590f1da7d9a

seraphki

Awesome! Thanks for that =D
Looks similar to what I did which is a huge relief. Going to create a new class and throw that in there so its cleaner =3

Though I do have one question about your CreateAtlasAsset method that takes Textures - you search the atlas file for the texture names, but if you're recieving textures in an array, is there any reason you can't just do:

for (int i = 0; i < textures.Length; i++)
{
   mat = new Material(shader);
   mat.mainTexture = textures[i];
   break;
}

As someone writing a tool I understand why you wouldn't - just to make sure that the textures they hand in are the textures that are in the atlas, but is there another reason? Our team is small enough that I'd be willing to take that shortcut, as long as there isn't another reason not to do it.

Pharan

Sure. If you can ensure in your case that the texture array is always 100% correct, then go for it!
You could do it on the editor side too, or just be super careful with the inspector.

30 Aug 2016 12:22 pm

These issues suck.

Maybe Asset Bundles weren't meant for ScriptableObjects? That doesn't sound right. Surely, DLC can contain arbitrary data and not just textures and 3D models and stuff.

The same-name-different-extension limitation is just crazy. What's going on?

We'll note down giving you some options for multi-page atlas material naming. Seems like the AssetBundle case makes that an issue where you normally don't have to care when the assets are auto-assigned into the AtlasAsset.

The fromAnimation array thing was fixed in the repo and unitypackage, but that code I linked above shows the workaround. It's marked "// pre-patch workaround". Just need to make sure some of the public fields that are normally populated in asset form are filled. (or in the actual fix version, ignored)

水岸上

I find a simple way that is for the component of SkeletonGraphic and SkeletonRenderer SkeletonAnimation to resolve the assetbunle-pink-problem.

1.put two shader of Skeleton and SkeletonGraphic into a Resources folder.

2.add code into SkeletonGraphic :

protected override void Start()
{
    base.Start();
    material = new Material(Resources.Load<Shader>("SkeletonGraphic"));
}

3.the SkeletonAnimation is the subclass of the SkeletonRenderer, so only in the SkeletonRenderer add code:

public virtual System.Collections.IEnumerator Start()
{
    yield return 0;
    var mat = new Material(meshRenderer.material);
    mat.shader = Resources.Load<Shader>("Skeleton");
    meshRenderer.material = mat;
}

and then when we load assetbundle that made by spine, it will be set right shader and displays normally.

Pharan

Thanks for sharing, 水岸上!