First of all I’d like to say you’re doing an amazing job with the Unreal Engine and so far I’ve really enjoyed using it.
My background is in VFX/offline renderers and a feature I was looking for the other day is the ability to inspect a pixel value while hovering the mouse in the viewport, something like what Nuke has:
Knowing what the values (RGBA, EV) are before the tonemapping process would be great! I’ve been looking around to see if something’s already implemented but so far no luck.
Funny you should mention that, this very topic came up while we were doing the GDC Kite demo since we used Nuke so much. Martin Mittring added this feature. It will be in 4.8.
To access it, in the viewport click Show → Visualize → HDR (Eye Adaption)
It looks like this (in addition to the hdr curve at the bottom of the screen which you should have already):
