Problem with materials after creating Asset Bundle

Questions & Answers
1

I have a script that creates asset bundles. I pulled it from http://unity3d.com/support/documentation/ScriptReference/BuildPipeline.BuildAssetBundle.html?from=AssetBundle and used it in its entirety.

When I load the asset bundle at runtime and instantiate a prefab via GameObject.Instantiate(), the material associated with the prefab has all of the transparent areas replaced with yellow and the rest of the material is a pseudo-negative image. However, the textures are loaded just fine. It’s only the materials that are affected.

I am using the EZGUI and SpriteManager2 plugins. This may or may not be a factor. Before including these prefabs in the asset bundle, they worked perfectly. What could be causing the yellow negatives in the materials?

3

This might or might not help you:

We do this after loading a bundle:

	var materials = bundleEntry.bundle.LoadAll(typeof(Material));

	foreach(Material m in materials)
	{
		var shaderName = m.shader.name;
		var newShader = Shader.Find(shaderName);
		if(newShader != null)
		{
			m.shader = newShader;
		}
		else
		{
			Debug.LogWarning("unable to refresh shader: "+ shaderName + " in material " + m.name);
		}
	}

We also make sure that all our shaders are under a “Resources” folder, so that they are available at runtime regardless of usage.

This seems to be required only on Windows and iOS (possibly other platforms), but not on MacOS. There was some speculation that this is because shaders are considered “code”, and not included in the bundle.

Note: This method is not perfect, since modifying assets in an asset bundles causes other errors. I’m investigating a good fix to this last one right now. It might work fine for your uses, though.

Asset bundles have many undocumented gotchas. good luck.

2

I was having a somewhat similar problem that you have seen in my comment, maybe this “solution” is not related at all to your problem but here it is. My issue was simply that I was using assetbundles of the wrong type. Basically I was targeting Android but when testing on PC, textures from the android bundles would show up as corrupted, in my case, purplish and semi transparent. But on the android device it was fine. To see the stuff well on PC, I needed to make PC asset bundles. That’s determined by the target you pass as parameter in BuildPipeline.BuildAssetBundles. So not a real issue, just a misunderstanding of the asset bundles on my part. Hopefully, your problem was the same thing.