Hi. It is possible I have some material settings wrong, otherwise this is a rendering bug.
I have a sprite in the scene with partial transparency. In the sprite material I use AlphaCompositing blend mode as I this content is used in video production and alpha compositing must be correct. Behind the sprite there is a plane actor with partial transparency as well. Its material blending mode is Translucent. When I move the camera, the blending order sometimes changes. Here are the screenshots:
As you can see in the second image the semi-transparent plane becomes blended in front of the image. This is wrong. And these flips happen dynamically when the camera is being moved along X axis back and forth with some amount of rotation around Z axis.
First ,thank for the tip.I wasn’t aware of this option. Second, as a graphics programmer myself I wonder why UE4 can’t correctly render transparent object (usually the technique is to disable depth and render back to front order all the non-opaque).We are not talking here about intersecting geometry (which is indeed a problem) Maybe because of the deferred mode? I need to check if in forward rendering mode the same happens. If it does I still believe it is a bug unless something in the UE very long pipeline is preventing correct alpha compositing on purpose.
