Hello,
I found a problem that the translucent-refractive material may be rendered in wrong order. The refractive object is somehow always rendered on top of the translucent but not refractive objects. Do we have any methods to avoid this ?
This is to be expected. Translucent materials are rendered in order based on the position of the camera. We sort translucency per draw call by camera distance. Per Pixel would solve this but it’s very expensive and we do not support that yet.
If you navigate to the other side of the white cube is the non refractive material not on top of the refractive material?
I have entered a bug report for this particular issue as UE-24998 and will keep you informed here as we investigate a solution to this issue. In the meantime as a workaround you can leave separate Translucency on and in the materials remove separate transparency per material which would allow you to keep the sorting.
I noticed that this bug is now listed as won’t fix; although I can’t see any explanation on the bug page.
Since the most common use case for refraction is on waters surface (which if anything you would want rendering before any other transparency) I’m assuming there must be some work around?