Unity3D export to Android with transparent background?

[infi2019]

@SharkyLV

Hi Aleksandrk,

Has anything changed since? I am using 2018.2 with preserved alpha buffer and 0,0,0,0 rgba for the camera

• if keep the “windowIsTranslucent: true” setting in Android when exported, the UnityPlayer keeps the transparency, but it is transparent through all the app views (like a hole through to the desktop)
  

• if I remove “windowIsTranslucent: true”, then the background becomes black

Have you solve the problem?

[ywj7931]

@aleksandrk

When I was implementing this, I was modifying the gradle project exported by unity to show additional native Android UI underneath the Unity view. I’m not sure if any other configuration will work properly

Hi, Does it work with iOS. Any solution to make it transparent in iOS?

[aleksandrk]

@ywj7931 yes, the same checkbox (it was renamed to “Render over native UI”).

[Cliwo]

@ywj7931

I am trying to export my unity project to other android projects, my Unity content will be an avatar, I am displaying my Unity content on a FrameLayout/RelativeLayout above another layout, is there anyway I can make my avatar’s background transparent? ( so that I can drag the avatar but still can see the layout on the background. a

For example: How to achieve the following? Right now,

Right now, its whatever background from Unity3D (sorry for my poor drawing):

Hi, I’m sorry to call you since quite some time passed.
I want to make something like you wanted but I think my result is quite different with yours.
Can you explain me what you made with more details? (ex. screenshot(?))

For now my app is like the image I uploaded.
top of screen, it shows unity view with ‘main menu’ not my activity. (it is like a hollow)
and below that, my activity comes

Thank you

[raviIOS]

@aleksandrk

@ywj7931 yes, the same checkbox (it was renamed to “Render over native UI”).

Still iam unable to get cleared color background of the unityView. Please any one could help to get the clear color backround of the unityView when integrating in the ios application.

[raviIOS]

@aleksandrk please could you help us on the transparent background of the unity while implementing in the native iOS for the 2018.0.3f2 version. It is still not changing the color while above settings is turned on. Could you help me know where is the background color implementation is written in the classes exported by the unity where we can check by changing the color of the background and get the result.

[aleksandrk]

Can you post a screenshot of your camera settings and of “resolution and presentation options” from the player settings?

[raviIOS]

@aleksandrk :this is the screenshot with the latest 2019 version of the unity as the option of the “Render over native UI” is available in this unity version.

[aleksandrk]

Is this the only camera that renders to the screen?

[raviIOS]

@aleksandrk : Yes, this is the only camera setting. Attaching the MethalHelper.mm file also which we get after exporting the Project in ios environment

4412095–401887–MetalHelper.txt (16.2 KB)

[aleksandrk]

Line 69 in MetalHelper.mm sets the background color for the layer. When Unity renders a frame, it’s alpha-blended with the underlying view.
I’m not sure, what exactly are you trying to achieve and what’s not working

[raviIOS]

@aleksandrk

Line 69 in MetalHelper.mm sets the background color for the layer. When Unity renders a frame, it’s alpha-blended with the underlying view.
I’m not sure, what exactly are you trying to achieve and what’s not working

I need the background of the unityview to be transparent so that the rendered view looks like the part of the view. Object should be visible as attached with the screenshot. In the POC, the background white color should be transparent so that the car seems like the part of the background view.

[aleksandrk]

It should work
Please make a bugreport.

[Vishakh_A_V]

@SharkyLV

So it seems that UnityPlayer on Android is using a SurfaceView which displays the content in a separate “window” and has no view hierarchy with other views in your activity. Therefore you cannot overlay with other UI elements.

There was a hack somewhere on GitHub I found that overrides some internals of UnityPlayer for it to use TextureView instead. TextureView is a normal view hierarchy member and can be animated, or overlayed with other UI views.

The problem, however, (and the reason why they chose SurfaceView) is as soon as a view in a view hierarchy updates, it propagates an update/redraw to other other views in the hierarchy (up to the root view). UnityPlayer updates many times per second, prompting other views to update many times per second, therefore resulting in a very slow fps.

There might be a way to isolate the updates of the UnityPlayer and do not propagate them to other views, but if you have an overlay view on top of or below the UnityPlayer, I don’t see how it’s possible not to redraw them.

TLDR; Unity uses SurfaceView which uses a separate “window” and is not part of your activity view hierarchy.

Upon research, I found that the SurfaceView is rendered at the last of the window different from the view hierarchy and that it is possible to move the SurfaceView to the top by using SetZOrderOnTop(true) on SurfaceView during the time of instantiation. A sample code would be to modify the onCreate of UnityPlayerActivity -
@ protected void onCreate(Bundle savedInstanceState)
{
requestWindowFeature(Window.FEATURE_NO_TITLE);
super.onCreate(savedInstanceState);

mUnityPlayer = new UnityPlayer(this);
try{
UnityPlayer view = (UnityPlayer)mUnityPlayer.getView();
Field f = view.getClass().getDeclaredField(“s”);
f.setAccessible(true);
SurfaceView sf = (SurfaceView) f.get(view);
sf.setZOrderOnTop(true);
}catch(Exception e){
}

setContentView(mUnityPlayer);
mUnityPlayer.requestFocus();
}
The transparent pixels that were causing a hole to the desktop could be fixed by creating a dummy background view and adding it to UnityPlayer’s FrameLayout.
However, the downfall to this would be that other system overlays by plugins like AdMob will not be able to render above UnityGame(SurfaceView).
Also I found that custom view behind transparent area(unity game) was found consuming touch events and unity game on transparent area couldn’t capture touch events!

[raviIOS]

aleksandrk : https://fogbugz.unity3d.com/default.asp?1145401_n611a41p768value.

Bug report is locked for the above issue

[Umresh]

@yasirkula

Also works with 2017.3.0f3. Camera background color should be 0,0,0,0 though, otherwise the background was tinted for me.

Does this work on webgl builds?

[aleksandrk]

@Umresh no, it’s Android and iOS only.

[mokhabadi]

@aleksandrk

@Umresh no, it’s Android and iOS only.

Hi! I’m trying to create a transparent app using unity but i can’t. i created an empty 3D project in unity 2019.4.9f1. i set the camera clear flags to transparent black (0,0,0,0), i set the "Render over native UI’, i removed Vulkan, i built for android and tested on my android 10 phone. it is not transparent. can you please tell me what is wrong? Thanks in advance!

[aleksandrk]

Hi!
Can you please report a bug?
Thanks!

[RDudnikovTangoMe]

I’ve checked a lot of unity versions so I think 2019.2.9f1 is most newest and stable for this issue until it fixed in 2020 versions.

BTW I’ve reported a bug.

Preset 2D
Default scene with camera’s clear flags is set to Solid Color (0,0,0,0)
Start in fullscreen mode is unchecked (if you have this option in the editor, not sure that affects)
Preserve frame-buffer alpha is checked (Render over native UI)
Disable splash screen (not sure that affects)
Not worked
2020.1.6f1
2019.4.12f1 (with or without Vulkan)
2019.3.15f1 (with or without Vulkan)
2019.3.0b4
2018.4.28f1
2018.4.21f1
2018.4.17f1
2018.4.15f1
Worked
2019.2.9f1
2018.4.14f1
2018.3.14f1
2018.2.21f1