ETC1 + Alpha Feature

Hi there, i'm trying to use this new option, however, as soon as i tick the checkbox of the compressed sprite, it fallbacks again to ETC2.
ETC(default) is overriding in Build Settings aswell.

 

I am seeing this issue also, and confirm it is present in 5.2.0f3 that has just been released ...

 

Yes. Is this feature even works? I've spent all day trying different approaches in packing asset bundles with different settings, but result is the same - all textures in ETC2.

Log messages looks like this:
Built-in Texture2D: SpriteAtlasTexture-map-2048x2048-fmt47

fmt47 is TextureFormat.ETC2_RGBA8.

 

sandboxed,

Hi. Have you really tried this on a real Android device? Because what I see is this ugly non-alpha ETC compressed texture.

When Texture Compression is set to "Don't override", atlas get compressed to ETC2, NOT ETC1. I assuming this by looking at Editor.log:
- Packing atlas (spp2) of 1 sprites. Settings: Format: RGBA Compressed ETC2 8 bits

When Texture Compression is set to "ETC (default)" atlas get compressed to ETC1, but no any alpha atlases is built, and the size of non-alpha atlas is the same as the texture, so no any alpha get pushed to this atlas somewhere "near".

 

The documentation at http://docs.unity3d.com/Manual/class-TextureImporterAndroid.html does not say to set the build texture override to ETC (default), it could do with updating.

Also it seems misleading in that first screenshot, where it says "RGBA Compressed ETC2 8bits (Atlas)" at the bottom, when the atlas format is in fact ETC1 + Alpha texture.

The sprite packer's Alpha/RGB toggle button (the little rainbow thing at the top) does not work in this case either, the Alpha appears all white.

The tickbox for compress using ETC1 also disappears if you switch the texture to Advanced mode.

These have been logged as case 725748.

 

Hello! I think I know what's the problem. I try to use this method with UI elements and it's failed because in UI shader no any alpha ETC1 support, but in Sprite-Default shader I see this _AlphaTex field and all supporting stuff.

Sprites are part of UI and I think we all agree that UI shader also need support for ETC1+Alpha compression.

Is this possible? Can we see it in a patch update? If not and this is absolutely impossible, you should fix documentation so that it will say about SpriteRenderer only and not about sprites in general.

 

Hey sandboxed,

My results do not match your results. Any guess what I'm doing wrong?

I'm using 5.3.0f4. All of the sprites in the loadingdoors atlas that have alpha are checked for "Compress using ETC1". The MunkySpritePacker is just the example code with "entry.settings.allowsAlphaSplitting = ti.GetAllowsAlphaSplitting();" included.

I want 2 ETC 1 textures, but I'm still getting ETC2 in the atlas and on device.

 

Hi - what's the status of the bug with ETC1 split alpha not working on UI elements - was it resolved as part of the 5.3 release (couldn't find it mentioned in the release notes) ? If not is there an ETA ?

When you mentioned above that there's a bug on it, is it this one in the issue tracker :

http://issuetracker.unity3d.com/iss...-when-the-used-sprite-is-with-packing-tag-set


Thanks!

 

Looking at the default sprite shader, it has [PerRendererData] on _MainTex in the properties block, but not for _AlphaTex (which doesn't even appear in the properties block, only in the shader code itself).

Is there any reason for this? Presumably each _AlphaTex variant needs to be passed in via the MaterialPropertyBlock like the main texture does ?

 

Understood.

Did anything else change with how alphaed sprites are rendered in Unity 5.3 upwards?

I ask as on upgrading from 5.2.1 to 5.3.1, the sprites I have using the ETC1 alpha split no longer render correctly (I made no other changes) - they have solid blocks around them, i.e. the alpha texture is being ignored.

These are straight SpriteRenderer's, not UIImages.

Is there something new that needs to be setup to make them work or should I log a bug - it is very easily reproducible.

 

I download the unity5.3 UI source code project and rebuild UnityEngine.UI.dll when i modified the Image Component override material property(use the modified UIDefault shader) and sprite property (set _AlphaTex),partial code like these: defaultmaterial.shader = shader.Find("UI-DefaultAlpha"); defaultmaterial.SetTexture("_AlphaTex",sprite.associatedAlphaSplitTexture);but it just did not work on unity5.3p2 ,the background is black,There should be something wrong with the sprite.associatedAlphaSplitTexture generated.Because this work fine on unity5.3f1.

 

On unity5.3f1 I found that modified UI Image component nested use has problem when set sprite.associatedAlphaSplitTexture via code (sprite.associatedAlphaSplitTexture != null).Which release unity version would fixe Image component problem when using ETC 4 bits split Alpha channel?(sorry,please forgive my poor english)

 

Hi, facing the same issue I have vote for. But how to workarround. I have an heavy UI game with many atlas. I want to create a build with ETC1 + alpha with atlas for UI image for older devices.
I will create a ETC2 build for newest supporting opengl es 3.0.

How to create and setup shader for UI Image etc1?

 

@sandboxed : it's true we can access the associatedAlphaSplitTexture for a given sprite, but actually setting this alpha texture on a UI image poses some challenges:

Because the UI.Image class does not inherit from Renderer, there also does not seem a way to setup a MaterialPropertyBlock for each image instance. Does this mean a new material needs to be created (and assigned to the UI image) for each possible variant of alpha split texture ?

 

First,Thanks for your replay. But it seems does not work properly when RGB and RGBA(compressed by split alphaTexture) textures exist at the same time. It seems to be like these:
if(AlphaEnable)
{
color.a *= tex2D(_AlphaTex,IN.texcoord).r;
}
There have another problem I meet, The FrameDebugger display that the generated _AlphaTex is white

 

The correct state should like this:

 

The sprite packer seems does not work properly if i use the editor script set the sprite tag and reimport .the atlas does not regenerate(unity 5.3.1 p2)

 

@sandboxed: in your solution above, I don't think any of those steps actually assign _AlphaTex from a script, and nothing actually seems to read from associateAlphaSplitTexture ?

Shouldn't there be another step that does something like:

material.SetTexture("_AlphaTex", sprite.associatedAlphaSplitTexture);

?

Though as I mentioned earlier, this needs a new material for each different alpha texture.

 

Code (csharp):

1.  
2.         //UGUI Graphic.cs modified like this:
3.         protected virtual void UpdateMaterial()
4.         {
5.             if (!IsActive())
6.                 return;
7.  
8.             canvasRenderer.materialCount = 1;
9.             if (alphaTexture != null)
10.             {
11.                 materialForRendering.SetTexture ("_AlphaTex", alphaTexture);
12.                 materialForRendering.SetFloat ("AlphaEnable",1f);
13.             }
14.  
15.             canvasRenderer.SetMaterial(materialForRendering, 0);    // I tested found that needs  a new material for each different alpha texture .The other problem is the associatedSplitTexture format is fm4 but ETC should be fm34 )
16.             canvasRenderer.SetTexture(mainTexture);
17.         }
18.  
19.  
20.         static public Material defaultGraphicMaterial
21.         {
22.             get
23.             {
24.                 if (s_DefaultUI == null)
25.                     s_DefaultUI = Canvas.GetDefaultCanvasMaterial();
26.  
27.                 if (s_defaultShader == null)
28.                 {
29.                     s_defaultShader = Shader.Find ("UI/DefaultAlpha");
30.                     s_DefaultUI.shader = s_defaultShader;
31.                 }
32.                 return s_DefaultUI;
33.             }
34.         }
35.  
36.         // UIImage changed like this:
37.         public override Texture alphaTexture
38.         {
39.             get
40.             {
41.                 if(m_Sprite != null)
42.                 {
43.                     return m_Sprite.associatedAlphaSplitTexture;  // this code does not work (just a                          white texture so i use mine)
44.                 }
45.                 return null;
46.             }
47.         }
48.  

Code (csharp):

1.  
2. Shader "UI/DefaultAlpha"
3. {
4.     Properties
5.     {
6.         [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
7.         [PerRendererData] _AlphaTex("Sprite Texture", 2D) = "white" {}
8.         _Color ("Tint", Color) = (1,1,1,1)
9.        
10.         _StencilComp ("Stencil Comparison", Float) = 8
11.         _Stencil ("Stencil ID", Float) = 0
12.         _StencilOp ("Stencil Operation", Float) = 0
13.         _StencilWriteMask ("Stencil Write Mask", Float) = 255
14.         _StencilReadMask ("Stencil Read Mask", Float) = 255
15.  
16.         _ColorMask ("Color Mask", Float) = 15
17.  
18.         [Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip ("Use Alpha Clip", Float) = 0
19.     }
20.  
21.     SubShader
22.     {
23.         Tags
24.         {
25.             "Queue"="Transparent"
26.             "IgnoreProjector"="True"
27.             "RenderType"="Transparent"
28.             "PreviewType"="Plane"
29.             "CanUseSpriteAtlas"="True"
30.         }
31.        
32.         Stencil
33.         {
34.             Ref [_Stencil]
35.             Comp [_StencilComp]
36.             Pass [_StencilOp]
37.             ReadMask [_StencilReadMask]
38.             WriteMask [_StencilWriteMask]
39.         }
40.  
41.         Cull Off
42.         Lighting Off
43.         ZWrite Off
44.         ZTest [unity_GUIZTestMode]
45.         Blend SrcAlpha OneMinusSrcAlpha
46.         ColorMask [_ColorMask]
47.  
48.         Pass
49.         {
50.         CGPROGRAM
51.             #pragma vertex vert
52.             #pragma fragment frag
53.  
54.             #include "UnityCG.cginc"
55.             #include "UnityUI.cginc"
56.  
57.             #pragma multi_compile __ UNITY_UI_ALPHACLIP
58.            
59.             struct appdata_t
60.             {
61.                 float4 vertex   : POSITION;
62.                 float4 color    : COLOR;
63.                 float2 texcoord : TEXCOORD0;
64.             };
65.  
66.             struct v2f
67.             {
68.                 float4 vertex   : SV_POSITION;
69.                 fixed4 color    : COLOR;
70.                 half2 texcoord  : TEXCOORD0;
71.                 float4 worldPosition : TEXCOORD1;
72.             };
73.            
74.             fixed4 _Color;
75.             fixed4 _TextureSampleAdd;
76.             float4 _ClipRect;
77.  
78.  
79.             v2f vert(appdata_t IN)
80.             {
81.                 v2f OUT;
82.                 OUT.worldPosition = IN.vertex;
83.                 OUT.vertex = mul(UNITY_MATRIX_MVP, OUT.worldPosition);
84.  
85.                 OUT.texcoord = IN.texcoord;
86.                
87.                 #ifdef UNITY_HALF_TEXEL_OFFSET
88.                 OUT.vertex.xy += (_ScreenParams.zw-1.0)*float2(-1,1);
89.                 #endif
90.                
91.                 OUT.color = IN.color * _Color;
92.                 return OUT;
93.             }
94.  
95.             sampler2D _MainTex;
96.             sampler2D _AlphaTex;
97.             float AlphaEnable;
98.  
99.             fixed4 frag(v2f IN) : SV_Target
100.             {
101.                 half4 color = (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd) * IN.color;
102.                
103.                 if(AlphaEnable)
104.                 {
105.                  color.a *= tex2D(_AlphaTex,IN.texcoord).r;
106.                 }
107.  
108.                 color.a *= UnityGet2DClipping(IN.worldPosition.xy, _ClipRect);
109.                
110.                 #ifdef UNITY_UI_ALPHACLIP
111.                 clip (color.a - 0.001);
112.                 #endif
113.  
114.                 return color;
115.             }
116.         ENDCG
117.         }
118.     }
119. }
120.  
121.  

I modified the UI Graphic source code,use myself alpha texture(the generated associatedAlphaSplitTexture is white) ,but the big problem is the sprite packer generated alphaTexture and the mainTexture uv is different,so i use uv1 transfer into the shader

 

Thanks @sandboxed I will try it.

 

May you explain [PerRenderData]' specific usages? There are no specific document descriptions.Does it have any relationship with the MaterialPropertyblock? "Use it in situations where you want to draw multiple objects with the same material, but slightly different properties."?

 

But CanvasrRender does not have extend from Render component.I don't know how to use one material render multiobjects by canvasrender way(Graphics.DrawMesh does have this property), I tried the way that you provided(set _AlphaTex )but the performance suffered a lot(each different texture use one different material).May you show me the right code (or correct solution)?

 

Hi,
I have give a try and lear how to configure a shader. I have modify UI default shader with a alpha tex. But indeed we need to assign the atlas texture alpha to this UI Image. Add a custom script is out of question with a heavy UI 2D game.

I have installed unity 5.3.2f1 but issue is always here. any fix comes in next build?

 

@xjqxzyr do you found a work around? I am near to build a release and no solution for me except make several build with different compression (ATC, ETC2, PVRTC, ASTC).

 

I meet a big problem when i want to use image(and atlas compress)with ETC1 format.There dose not have a rigth way to set alphaTexture and a MainTex to a canvasRender at the same time,there could apear flicker problems.If you unity guys fixed this problem,There could be another problem you could meet,spritepacker just do not packer textures under Resources folder.And you can not load a sprite dynamicly out of resource folder.I could say NGUI has a good managerment about ui textures.

 

I am having a similar problem, I did find a weird workaround that worked for me on my project.
I tried to compress a texture with an alpha channel into ETC1 by checking the ETC1 checkbox override.
In the editor it appeared as an ETC2 texture and When I compiled to the device which only supports ETC1, I noticed that a 2048x2048 texture (from the resource folder) was taking 16mb (using a snapshot from the memory profiler) and not 4mb a ETC1 texture should. but another texture that had mipmap checked did get compressed to ETC1 and was taking up 5.3mb on the device. so I checked the mipmap option on the texture that didn't compress and it actually did compress it this time although in the editor it was still displaying as ETC2.
I tried to reproduce this on a new Project but for some reason it doesn't work and UT will not compress ETC1 textures for textures with alpha channel with or without mipmap checked.
I don't understand what is different between the two projects, in the build settings they are both set as ETC1(default) override. in the Player setting i set both projects to work only with openGLes2.
Anyway, try to check mipmap for the texture and it might work on the device.

all tests were made using Unity 5.2.4.f1

 

@UVMarko vote for issue: https://issuetracker.unity3d.com/is...-when-the-used-sprite-is-with-packing-tag-set

Hope this will help to be fixed soon. I will try in my project to check mipmap but I am already near 100Mo APK files.

 

@sandboxed would you tell us the specific support date?

 

I have search in beta releases notes and this issue will not be fixed.

 

This feature is very important for Android game. Any dates?

 

Great.

 

hi, I add an extra component for support etc+alpha.
But if use Image component and myImage as the same time, the alpha texture will affect another Image Component.


How to do let the myImage shader don't affect the Image component.

As Code：

image.materialForRendering.shader = Shader.Find ("UI/MyDefault");
image.materialForRendering.SetTexture("_MainTex", srcTex);
image.materialForRendering.SetTexture ("_Alpha2Tex", aplitAlpha.AlphaTexture);



Thanks!!!

 

hi, I add an extra component for support etc+alpha.
But if use Image component and myImage as the same time, the alpha texture will affect another Image Component.

How to do let the myImage shader don't affect the Image component.

As Code：

image.materialForRendering.shader = Shader.Find ("UI/MyDefault");
image.materialForRendering.SetTexture("_MainTex", srcTex);
image.materialForRendering.SetTexture ("_Alpha2Tex", aplitAlpha.AlphaTexture);


Thanks!!!

 

hi,
I add an extra component for support etc+alpha.
But if use Image component and myImage as the same time, the alpha texture will affect another Image Component.
The alpha texture can affect another sprite ?

How to do let the myImage shader don't affect another sprite ?

Thanks !

 

You try to render with Sprite Packer atlas Image?

 

https://support.unity3d.com/hc/en-us/articles/207051116-How-can-I-add-Alpha-to-ETC1-Compression-