Hi Neutronux,
Lava is a perfect example for my case actually as Lava fits a scientific phenomena called Black Body Radiation which has an absolute mapping between Temperature in Kelvin to RGB.
I’ve simulated Lava (in VFX) at realistic Kelvin temperatures so the values can be mapped directly through a Black Body node and return a RGB colour that goes into the Tone Mapper.
My guess is the UE4 lava was artistically created to look ‘right’ but isn’t sitting in physically correct units. 4.15 would probably make this easier.
Real units are just a much more reliable platform to work in. Watts, f-stops, IOR, kilogram, gravity and tight PBR materials make life easier as you can pick up scientific journals (even going back decades) which can explain the interaction between them all - regardless of which software one uses.
After this point it’s all about how you creatively ‘expose’ the image i.e Instagram vs RAW