Problem rendering output with transparency background

[z25380917kg3u]

I have a single text motion graphic layer in solid white.When I check, the background is a transparency.  I then go to render a quicktime .mov and set the codec to AppleProRes 4444 with an alpha channel.  I also check that RGB + Alpha is enabled.   After rendering, in playback I still see a black background to the text instead of the transparency.  Please see the attached image of my settings before rendering. 

I have looked and looked but can't find a solution to my problem.  Any help would be greatly appreciated.  Thanks

[Mylenium]

In what program do you verify the output? Transparency will only show up in other professional video programs, not standard players.

Mylenium

[z25380917kg3u]

a vlc player

[Mylenium]

You answered your own question. Reimport the file in AE or check in Premiere to check for transparency, not VLC or whatever other player.

Mylenium

[z25380917kg3u]

I just tried reimporting the rendered file in AE and it plays with a black background.

[z25380917kg3u]

I believe I'm following the instructions needed to do this, but here's another file with the settings I'm using.

[Rick Gerard]

Did you enable the transparency grid in After Effects? Did you check the Project Panel Info display when importing the footage?

[z25380917kg3u]

Thanks for your reply!   Here's the crux of my problem.  I have determined how to render an mov or avi file with the transparency background working.  However, I need to use this in Epic's Unreal gaming engine UE 4 and UE 5 (if you're unfamiliar, this is becoming one of the most popular platforms to develop games and post and pre post for movies).  When I convert the .mov file to an mp 4, the black background plays instead of, in my case, a solid text with a transparent background.  Can you help with any suggestions?   Thnx

[Rick Gerard]

Check the documentation for Epic's Unreal gaming engine. They have to give you supported file formats and workflows somewhere. You will never get RGBA in an MP4. It is impossible. You can render an 8-bit black and white MP4 and an 8-bit RGB MP4, then use the black and white copy as a track matte if that format is supported. You could render a Tiff sequence or any other supported file format. You cannot get RGBA in an MP4. 

[Andrew Yoole]

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@z25380917kg3u wrote:

When I convert the .mov file to an mp 4

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That's the problem.  MP4 files cannot contain alpha channels.

Unreal Engine supports Quicktime ProRes formats. so you can use them, but the file size will be huge - not really suitable if you're developing online content.

UE also supports PNG and EXR image sequences, both of which can contain alpha channels.  Or, you can output seperate RGB and alpha streams to MP4 and use the alpha channel as a matte within UE.  Or, worst case scenario, UE has a keyer so you could render onto an appropriate key colour and then key it back out in UE.

https://forums.unrealengine.com/t/playing-a-video-with-a-alpha-channel/406736/11