UE4- Stereo Masked Texture
I am interested in bringing live green screen shot footage into a UE4 environment.
To get a different image per eye use a lerp and a custom node:
Create a custom node in your material editor and add "return ResolvedView.StereoPassIndex; " (Note: output type should be Float1)

To get a material that uses the alpha channel (I'm using a PNG with alpha) set blend mode to masked, this give an Opacity Mask input. Use a lerp to pick between the left and right RGB and Alpha using the above custom node.

OK that works for still textures, how about image sequences? Follow this video on media textures to make a moving texture. I'm not sure why Unreal requires so many steps for this, but basically:
- Create an image media source
- Create a player for media source
- Create a Texture that references the player
- Add to the level blueprint to start the player when play begins