Can I ask how you did this? I’m trying to get the alpha channel from a ProRes 4444 video but it’s like it doesn’t exist. I’ve got the AJA plugin installed in the project. At this rate I’m going to have to consider the other poster’s idea of making a 2nd half of the video which is just what’s in the alpha channel, which is a mega pain in the ■■■■.
Hello!
Do you have media players for 5.1 or 5.2?
2 videos-- what format are the videos?
Just to give a more up to date/alternative reply to this, now that Bink is owned by Epic and included with Unreal, you can simply use that. It works well with alpha layers and everything is included in the engine, so no messing about with exporting separate alpha layers, streaming individual frames or dealing with other codecs and encoding.
The Bink encoding tool/player is to be found in \Engine\Binaries\ThirdParty\Bink in the Unreal installation folder.
Here is another technique: make background black, in material use blend mode additive. That will make all black pixels transparent.
The easiest way is to make the background completely black (=0), multiply it by 100 (or any other big number) and plug it into opacity mask input.
It makes areas with a value above 0 greater than the mask threshold while black staying 0.
If you want to know how to make a video material↓
One really fast and easy way to get video and video with alpha to work is using the new Media Plate Actor. For non-alpha, drop media (png, exr, mp4, mov, avi) into Content Browser. Drop that media source into the scene or bind it in sequencer for cinematics. It will create a default (sort of hidden) Material Instance for you.
For alpha, add File Media Source in content browser, double click, set the path to your media. Drag this new File Media Source into scene. It seems to setup alpha by default now (5.4.2) but if not, double click the default material and set blend mode to Masked or Translucent. Opacity node is already setup for you. You can also bind this asset to Sequencer for Cinematic control.
These methods avoid using the Media Player and creating new Materials method but do have some limitations so the old media method may still be needed. Either method, for me, the ProRez 4444 mov and PNG seq methods both support Alpha.
Use bink2 !!
Engine\Binaries\ThirdParty\Bink
and you need bink plugin, then create a BinkMediaPlayer