This is not a solution. Why have High Resolution Capture option in the first place? With most high end graphic card still only having 8GB of Video RAM, the current implementation is useless for Raytracing. I can’t take shots higher than 3X screen resolution. And why need it large? Billboards. Typical billboard even at 30dpi require 14,400 pixels width which UE4 currently can’t deliver with Raytracing on RTX-2080. I can only get half that resolution.
Needs a way to offload the buffer to system RAM even if this takes longer.
Meanwhile, as a workaround, I render smaller image with Raytracing and blow it up. Then render larger full size image without Raytracing. Then retouching them to sharpen some edges back. But really would prefer not to do this.