[SOLVED!] Windows: Transparent window with opaque contents (LWA_COLORKEY)?

Hi! Sorry for necro this old post, but this is the only thing I found about this...
I have problems making the window click-through unless there's some collider or UI in front.

I can have a fully click-through window, or a non-click-throughable window

What I got so far is that if I use:
SetWindowLong(hwnd, GWL_STYLE, WS_POPUP | WS_VISIBLE);
In the Start (). I have a click-able and transparent scene

And if I use:
SetWindowLong(hwnd, -20, 524288 | 32);
In the Start(), I will have a transparent and click-through scene

But I tried change between them using a Input key, and I can change from, click-able to click-through, but I cannot change from click-through to clickable...

I was debbuging the whole time, so I know the input Im using is being detected, but still dont work

This is the whole code:

Code (CSharp):

1. using System;
2. using System.Runtime.InteropServices;
3. using UnityEngine;
4.  
5. public class TransparentWindow : MonoBehaviour
6. {
7.     [SerializeField]
8.     private Material m_Material;
9.  
10.     private struct MARGINS
11.         {
12.         public int cxLeftWidth;
13.         public int cxRightWidth;
14.         public int cyTopHeight;
15.         public int cyBottomHeight;
16.         }
17.  
18.     [DllImport("user32.dll")]
19.     private static extern IntPtr GetActiveWindow();
20.  
21.     [DllImport("user32.dll")]
22.     private static extern int SetWindowLong(IntPtr hWnd, int nIndex, uint dwNewLong);
23.  
24.     [DllImport("user32.dll")]
25.     static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
26.  
27.     [DllImport("user32.dll", EntryPoint = "SetLayeredWindowAttributes")]
28.     static extern int SetLayeredWindowAttributes(IntPtr hwnd, int crKey, byte bAlpha, int dwFlags);
29.  
30.     [DllImport("user32.dll", EntryPoint = "SetWindowPos")]
31.     private static extern int SetWindowPos(IntPtr hwnd, int hwndInsertAfter, int x, int y, int cx, int cy, int uFlags);
32.  
33.     [DllImport("Dwmapi.dll")]
34.     private static extern uint DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS margins);
35.  
36.     const int GWL_STYLE = -16;
37.     const uint WS_POPUP = 0x80000000;
38.     const uint WS_VISIBLE = 0x10000000;
39.     const int HWND_TOPMOST = -1;
40.  
41.     void Start()
42.         {
43. #if !UNITY_EDITOR // You really don't want to enable this in the editor..
44.  
45.         var margins = new MARGINS() { cxLeftWidth = -1 };
46.         var hwnd = GetActiveWindow();
47.  
48.         SetWindowLong(hwnd, GWL_STYLE, WS_POPUP | WS_VISIBLE);
49.  
50.         DwmExtendFrameIntoClientArea(hwnd, ref margins);
51.  
52. #endif
53.         }
54.  
55.     private bool clickThrough;
56.  
57.     void ChangeTransparency ()
58.         {
59.         var margins = new MARGINS() { cxLeftWidth = -1 };
60.         var hwnd = GetActiveWindow();
61.         if(!clickThrough)
62.             {
63.             Debug.Log("Window is click-able now");
64.             margins = new MARGINS() { cxLeftWidth = 0, cxRightWidth = 0, cyTopHeight = 0, cyBottomHeight = 0 };
65.             SetWindowLong(hwnd, GWL_STYLE, WS_POPUP | WS_VISIBLE);
66.             }
67.         else
68.             {
69.             Debug.Log("Window is click-through now");
70.             int fWidth = Screen.width;// is not
71.             int fHeight = Screen.height;// is not
72.             SetWindowLong(hwnd, -20, 524288 | 32);//is not //GWL_EXSTYLE=-20; WS_EX_LAYERED=524288=&h80000, WS_EX_TRANSPARENT=32=0x00000020L
73.             SetLayeredWindowAttributes(hwnd, 0, 255, 2);//is not // Transparency=51=20%, LWA_ALPHA=2
74.             SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, fWidth, fHeight, 32 | 64); //is not //SWP_FRAMECHANGED = 0x0020 (32); //SWP_SHOWWINDOW = 0x0040 (64)
75.             }
76.         DwmExtendFrameIntoClientArea(hwnd, ref margins);
77.         }
78.  
79.     void Update ()
80.         {
81.         if(Input.GetKeyDown(KeyCode.Q))
82.             {
83.             clickThrough = !clickThrough;
84.             ChangeTransparency ();
85.             }
86.         }
87.  
88.     void OnRenderImage(RenderTexture from, RenderTexture to)
89.         {
90.         Graphics.Blit(from, to, m_Material);
91.         }
92. }

 

When using @zalo10 solution, it does work. But it somehow invert the position of the mouse:

https://i.gyazo.com/1247bb061e14a9b7d554c86fce10dd05.gif

 

Thanks, Tautvydas-Zilys for the script! is working.

My default resolution is 800x600. But when I apply this "TransparentWindow" the resolution change to 816x639 losing the 4:3 proportion. Any idea to how to resolve this?

 

Can you tell me, please, how can I do it for Mac OS?

 

I enable aero on windows7,but it is tranparent on starting,then become black background quickly. How can I fix this? On windows10,it's fine.

 

necro.... I know but for completeness zalo10 solution works fine just to add for ui detection add:-

Code (CSharp):

1. public bool OverUI() { //Use sparingly
2.         //Set up the new Pointer Event
3.         PointerEventData m_PointerEventData = new PointerEventData(EventSystem.current);
4.         m_PointerEventData.position = Input.mousePosition;
5.         List<RaycastResult> results = new List<RaycastResult>();
6.         EventSystem.current.RaycastAll(m_PointerEventData, results);
7.         if (results.Count > 0) return true;
8.         return false;
9.     }

and change:

Code (CSharp):

1. clickThrough = !Physics.Raycast (mainCamera.ScreenPointToRay (Input.mousePosition).origin,
2.                 mainCamera.ScreenPointToRay (Input.mousePosition).direction, out hit, 100,
3.                 Physics.DefaultRaycastLayers);

to:

Code (CSharp):

1. clickThrough = !Physics.Raycast (mainCamera.ScreenPointToRay (Input.mousePosition).origin,
2.                 mainCamera.ScreenPointToRay (Input.mousePosition).direction, out hit, 100,
3.                 Physics.DefaultRaycastLayers)&&!OverUI();

 

it's working with multi windows ?

 

Just to note, this works in 2018.3.b12, but not in 2019.1.0a11 (yet)

 

You mean multi-monitor? If so YES I have it working with up to 8 monitors.

 

Any idea why? I'm still running 2018 and that could be a deal breaker for me on a 2019 upgrade.

 

Is anyone else having problems running this using Player Settings -> Scripting Runtime Version .NET 4.x Equivalent?

 

I'll answer my own question. If you change to Scripting Runtime = >net 4.x you need to also set the Api Compatibility Level to .NET 4.x

 

It's working again in 2019.1.7! (and 2019.2.0b6 and 2019.3.0a2). Big thanks to Unity for keeping this awesome functionality alive.

Per Tautvydas-Zilys, you have to make sure to UNCHECK "Use DXGI Flip Model Swapchain for D3D11" under Player Settings -> Resolution and Presentation. (I also had to tweak the shader to use alpha instead of color key, and havent tried clickthrough yet but the transparency is there, or NOT there I guess!)

 

Ya you beat me to it, I was just looking at 2019.1.7 release notes.

Windows: Added a Player Setting for reverting to BltBlt swapchain model which was used before 2019.1. This enables several scenarios like transparent window to be used once again (1107463, 1152570)

 

I have a question, how to open the application it's always at the right corner of the desktop.
I tried many ways on online but it didn't work

 

hi i got this to work for my overlay i was making for a game i play (osu!) but if i have the game in fullscreen (which i would like to have because otherwise the game has a little input delay) then the unity window does not overlay it anymore is there a way to fix this?

 

Needed information on how to do this recently and cant thank enough for this thread and this aswell.

My current desktop overlay allows the background applications to be interacted with, but loses focus on doing so. When not focused on my desktop overlay, my desktop overlay cannot register input. Is there a way for the desktop overlay to continue registering input while allowing the background applications to be interacted with?

 

it's working great but I need to capture screenshot and the current screenshot image does not have the desktop(background) in the screenshot any idea how can I have that desktop background also in the screenshot?

 

Hey Guys,I saw the comments above. This is similar to what I am trying to do .
I am working on Winforms. I am able to make the form transparent and click-through but When I load my HTML on it,then the page(HTML) itself becomes transparent and since it is click through, I am not able to get the control of HTML buttons ,links etc. as it access the control behind the form. I am new to CEF.
I want my HTML background to be transparent but not the buttons or labels etc on it and also want to interact with buttons not the window behind it whenever I click on it.
Thank You

 

Hello, sorry for the necropost,

I'm trying to build a transparent window and this solution works great ! But I was wondering if anyone knew how to keep the frame (border) of the window ? (with the minimize/maximize/close buttons etc)

Thanks

 

Is there any way to render the image at 100% visibility (to cover icons behind it)? Been messing with the variables but can't find a way.

See mrinalimangal1998's image 2 posts above.. how would you make his window pure white so you can't see what's behind??

 

This code to make the background transparent via color key does not work in 2019.3.13f1. The background is just solid black, and doesn't transparent

Can anyone plz advise?

Code (CSharp):

1. SetWindowLong(hwnd, -20, 524288 | 32);//is not //GWL_EXSTYLE=-20; WS_EX_LAYERED=524288=&h80000, WS_EX_TRANSPARENT=32=0x00000020L
2.             SetLayeredWindowAttributes(hwnd, 0, 255, 2);//is not // Transparency=51=20%, LWA_ALPHA=2
3.             SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, fWidth, fHeight, 32 | 64); //is not //SWP_FRAMECHANGED = 0x0020 (32); //SWP_SHOWWINDOW = 0x0040 (64)

 

Have you unchecked "Use DXGI Flip Model Swapchain for D3D11"?

 

Hi guys !

Do you know if it's possible to use this kind of script with an Universal Render Pipeline ? For now it works fine without but when I switch, background become black again, transparency seems to not working for now.

Thanks !

 

Amazing results here, but i need a small window, anyone knows how? I see that with a big screen the desktop performance is low... i want to do a small window to make it better to the user

 

Got the same problem. Well, actually it's working with URP, the problem comes only when you activate the "post-processing" option on the camera. It deletes the transparency information. See: https://issuetracker.unity3d.com/is...when-post-processing-is-enabled-on-the-camera

 

Is it possible to do this but so it also works on mac/linux? Sorry for the necro.

 

Looking for a solution for mac/linux also. Any updates on this?

 

I tried the code, and they are wonderful! Just one question: I had changed the default cursor, like this:


but when My State is "clickThrough", the Cursor sytle fallback to system default cursor. I try to use System.Windows.Forms.Cursor to hide the system cursor, but the result is the same, that's straight, any help will be appreciated.

 

I was wondering how you could use this with multiple monitors. Anyone know?

 

Does anyone know how to do this with a multitouch device? seems to calculate clickthrough by calculation Input.mouseposition but I am not sure how to get a touch position. I tried using Input.gettouch(0) (i think this one hangs),
leantouch and someone's script using wacom's dll but didnt really achieve anything....

I posted a thread here https://forum.unity.com/threads/transparent-window-app-with-multitouch-not-working.1093282/

but it looks like everyone is more active in this thread...(though sorry if it is still necro)

 

I just noticed an message from Epicei asking about multi monitor support. I think the issue is maybe more about settings then the code. Here is my current working settings as of release 2020.3.4f <DX11>




Of course NO Splash screen, and you most likely must have pro for this to work as it will force the splash screen.

On start I use at the very start:

Screen.fullScreenMode = FullScreenMode.Windowed;

If you allow it to goto full screen it just won't work correctly.

I've also noticed for some odd reason, for the very first time, and for no good reason it won't always run with the transparent working properly, windows GUI has some weird identifying itself going on that associates with it that won't work during the first run usually, and occasionally glitches.

 

Offtopic but EvalDaemon were you ever able to get this to work with Bloom Post Processing? I got a transparent window to work with Unity 2020.3 ... however, the post-processing created an artifact.

 

This doesn't work in Universal Windows Platform builds. I've tried, struggled to get the user32.dll symbols working. However, now that I have removed all errors in trying to find the required dlls, the transparency doesn't work. Does any know why this doesn't work in UWP?

 

Hello guys, would I be able to get this working with the 2D Renderer (URP) at all? When I use that, the background is no longer transparent, but stays black.

 

Can someone please tell me how to make the background transparent with opaque content but keeping the edges of the window?

something like this:

 

Hi, I am trying this code but I get a black background, only click through transparency. I tried different versions of Unity. What could be the cause ? Thankyou.

 

Same issue as Warriorforce, I am using Unity 2021.1.26 and I have everything exactly as explained here and in the Video made by CodeMonkey about this. I tried several solutions on transparency and I also unchecked the "Use DXGI Flip Model Swapchain for D3D11" option.
I do not mind not having click-through or the Splash screen at the beginning, I just really would like the Desktop to be visible in my application.
Or is it because I started developing in a 2D project in the beginning?

 

it is working with URP, just uncheck 'Post-Effect' (Camera&xxxPipelineSetting_Render.asset) and 'HDR'(xxxPipelineSetting.asset)

 

I recreated the technique with the 2D Core template of Unity 2020.3.36f1, and I had the problem where the background was all black. I am not using URP, but disabling HDR in the camera settings still fixed the problem.

 

I hate to resurrect a pretty old topic, but its such a niche subject I feel this is the only place I can go.

So I can get URP working with Code Monkeys tutorial, but is this essentially impossible via HDRP? given the rendering methods?

 

Well I can answer my own question now.

It still works in HDRP!!!!
Everything else still applies, there's just an additional setting. Just make sure your Color Buffer Format is set to the following on all Quality levels.

 

Is there a way to get it working / updated code to have it work with "Use DXGI flip model swap chain for D3D11"?

I don't want my game to be hindered performance-wise just for this effect!

 

Hey there! Sorry for the necro but this thread seems to remain the only real place for this, lol. I'm using Unity 2019.4.14f, it works fine and is and creates a transparent background with the scene visible, but the window itself behaves like any other Windows app and does not stay on top at all times. If I bring another app to the front, it covers the Unity app up. Using Windows 10, am I missing something? Here's the version of the code I'm using:

Code (CSharp):

1. using System;
2. using System.Runtime.InteropServices;
3. using UnityEngine;
4.  
5. public class TransparentWindow : MonoBehaviour
6. {
7.     private struct MARGINS
8.     {
9.         public int cxLeftWidth;
10.         public int cxRightWidth;
11.         public int cyTopHeight;
12.         public int cyBottomHeight;
13.     }
14.  
15.     [DllImport("user32.dll")]
16.     private static extern IntPtr GetActiveWindow();
17.  
18.     [DllImport("user32.dll")]
19.     private static extern int SetWindowLong(IntPtr hWnd, int nIndex, uint dwNewLong);
20.  
21.     [DllImport("user32.dll")]
22.     static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
23.  
24.     [DllImport("user32.dll", EntryPoint = "SetLayeredWindowAttributes")]
25.     static extern int SetLayeredWindowAttributes(IntPtr hwnd, int crKey, byte bAlpha, int dwFlags);
26.  
27.     [DllImport("user32.dll", EntryPoint = "SetWindowPos")]
28.     private static extern int SetWindowPos(IntPtr hwnd, int hwndInsertAfter, int x, int y, int cx, int cy, int uFlags);
29.  
30.     [DllImport("Dwmapi.dll")]
31.     private static extern uint DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS margins);
32.  
33.     const int GWL_STYLE = -16;
34.     const uint WS_POPUP = 0x80000000;
35.     const uint WS_VISIBLE = 0x10000000;
36.     const int HWND_TOPMOST = -1;
37.  
38.     void Start()
39.     {
40. #if !UNITY_EDITOR // You really don't want to enable this in the editor..
41.  
42.         var margins = new MARGINS() { cxLeftWidth = -1 };
43.         var hwnd = GetActiveWindow();
44.  
45.         SetWindowLong(hwnd, -20, 524288 | 32);
46.  
47.         DwmExtendFrameIntoClientArea(hwnd, ref margins);
48.  
49. #endif
50.     }
51. }

 

I think you've missed the actual step of setting the window to be on top.
That involves a call to SetWindowPos with the parameter HWND_TOPMOST.

 

Perfect, that was it!! I must have copied a version of the code that didn't have that call. Thank you!!

( the updated code, for those interested: )

Code (CSharp):

1. using System;
2. using System.Runtime.InteropServices;
3. using UnityEngine;
4.  
5. public class TransparentWindow : MonoBehaviour
6. {
7.     private struct MARGINS
8.     {
9.         public int cxLeftWidth;
10.         public int cxRightWidth;
11.         public int cyTopHeight;
12.         public int cyBottomHeight;
13.     }
14.  
15.     [DllImport("user32.dll")]
16.     private static extern IntPtr GetActiveWindow();
17.  
18.     [DllImport("user32.dll")]
19.     private static extern int SetWindowLong(IntPtr hWnd, int nIndex, uint dwNewLong);
20.  
21.     [DllImport("user32.dll")]
22.     static extern bool ShowWindowAsync(IntPtr hWnd, int nCmdShow);
23.  
24.     [DllImport("user32.dll", EntryPoint = "SetLayeredWindowAttributes")]
25.     static extern int SetLayeredWindowAttributes(IntPtr hwnd, int crKey, byte bAlpha, int dwFlags);
26.  
27.     [DllImport("user32.dll", EntryPoint = "SetWindowPos")]
28.     private static extern int SetWindowPos(IntPtr hwnd, int hwndInsertAfter, int x, int y, int cx, int cy, int uFlags);
29.  
30.     [DllImport("Dwmapi.dll")]
31.     private static extern uint DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS margins);
32.  
33.     const int GWL_STYLE = -16;
34.     const uint WS_POPUP = 0x80000000;
35.     const uint WS_VISIBLE = 0x10000000;
36.     const int HWND_TOPMOST = -1;
37.  
38.     void Start()
39.     {
40. #if !UNITY_EDITOR // You really don't want to enable this in the editor..
41.  
42.         int fWidth = Screen.width;
43.         int fHeight = Screen.height;
44.         var margins = new MARGINS() { cxLeftWidth = -1 };
45.         var hwnd = GetActiveWindow();
46.  
47.         SetWindowLong(hwnd, -20, 524288 | 32);
48.         SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, fWidth, fHeight, 32 | 64);
49.         DwmExtendFrameIntoClientArea(hwnd, ref margins);
50.  
51. #endif
52.     }
53. }

 

Yea I was wondering the same thing, it feels like it nukes the performance

 

I'm trying to work this on windows10 with unity 2022.3.7f1 but couldn't able to make it work yet. I read all 3 threads (from original to here) and this is getting too confusing. Does anyone have the working unity project files? So I can open and see the project in editor and read the working script etc.