Having the ability to have a 3D model on the screen and not in the game world anywhere that can render in respect to other UI UMG widgets with a transparent background.
The best I’ve gotten is using a 1x1 pixel viewport with FPreviewScene (otherwise the world doesn’t animate) setting a depth stencil value to be masked out to a Non-transparent render target, where both Chroma Key and opacity do nothing here… Then having another material poorly mask out a given color (with issues regarding texture blending and edges being miscolored) go into an image widget…
As far as I can see, there is no clean or nice way to do what I’m trying to do. (currently in 4.9)
What I currently have (right is viewport that will be 1x1 on screen somewhere):
Something similar that I’m trying to achieve: (Note both are in the UI not affecting the game)
Post process material: (Note, if alpha or chroma key in post process worked here, this would work how I want it to)
UI material: (Note: this would work if the sampler didn’t try to blend pixels [in the render texture neighboring pixels are ONLY 255, 0, 255, while in the sampler they are like 240 1 240 and variants])
This is only one example of this, and we plan to use this on many UI’s including our store.