[SOLVED] Random failures when regenerating atlas using internal packer (3.0.0e)

[yuriks]

(I'm using NGUI 3.0.0e and Unity 3.5.7f6.)

If I elect to use the internal sprite packer instead of Unity's one, I frequently get these two errors in the log when trying to update an existing atlas with new sprites:

Error: Unsupported image format - the texture needs to be ARGB32 or RGB24
UnityEngine.Texture2D:EncodeToPNG()
UIAtlasMaker:UpdateTexture(UIAtlas, List`1) (at Assets/NGUI/Scripts/Editor/UIAtlasMaker.cs:485)
UIAtlasMaker:UpdateAtlas(UIAtlas, List`1) (at Assets/NGUI/Scripts/Editor/UIAtlasMaker.cs:574)
UIAtlasMaker:AddOrUpdate(UIAtlas, Texture2D) (at Assets/NGUI/Scripts/Editor/UIAtlasMaker.cs:531)
UIFontMaker:OnGUI() (at Assets/NGUI/Scripts/Editor/UIFontMaker.cs:275)
UnityEditor.DockArea:OnGUI()

Error: NullReferenceException: Object reference not set to an instance of an object
System.IO.File.WriteAllBytes (System.String path, System.Byte[] bytes)
UIAtlasMaker.UpdateTexture (.UIAtlas atlas, System.Collections.Generic.List`1 sprites) (at Assets/NGUI/Scripts/Editor/UIAtlasMaker.cs:486)
UIAtlasMaker.UpdateAtlas (.UIAtlas atlas, System.Collections.Generic.List`1 sprites) (at Assets/NGUI/Scripts/Editor/UIAtlasMaker.cs:574)
UIAtlasMaker.AddOrUpdate (.UIAtlas atlas, UnityEngine.Texture2D tex) (at Assets/NGUI/Scripts/Editor/UIAtlasMaker.cs:531)
UIFontMaker.OnGUI () (at Assets/NGUI/Scripts/Editor/UIFontMaker.cs:275)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture)

The atlas image then gets replaced with an empty asset. I'm not modifying the atlas texture import options, they're at the NGUI defaults. If I delete the texture and generate it again it works fine.

[ArenMook]

Curious. Replace line 480 in the UIAtlasMaker -- it uses RGBA32. Change it to ARGB32.

[yuriks]

On my copy of the file 480 is a closing brace. Line 474 is:

1. tex = new Texture2D(1, 1, TextureFormat.ARGB32, false);

That is, it's already ARGB. Didn't find any references to RGBA32 on the file.

This is how the import settings look like on the failed file:

[ArenMook]

Sorry I meant NGUIEditorTools.cs.

[yuriks]

Changed, same results.

[ArenMook]

Find the other RGBA32 in that file and change it as well.

[yuriks]

That one seems to have fixed it, I can update the atlases without any issues now. Cheers for the quick responses!