I'm starting to add some camera sensor and lens attributes into Hyperion. So far it's just simple ones, including the ISO and T-stop settings. These two items affect the brightness of the image. The T-stop also affects the depth of field, though I haven't implemented this yet.
This means the render engine now has some exposure control. The idea is to mimic real world photography, so it's a good thing to be thinking about.
I'm using T-stops because they're a measured amount of light that comes out the back of the lens. F-stops are similar, but not the same. They're the theoretical amount, but the actual light that gets through (often referred to as transmittance) means it's not a perfect amount. T-stops measure the actual light, whereas F-stops are the theoretical.
The lens on my cinema camera measures in T-stops, because the manufacturer has measured the light coming out the back of the lens.
The engine is getting close to being able to be used on something. I have lots of projects I want to make with it, but really need a much simpler one to start with. I'm having to seriously consider buying another computer before I do as well. Hyperion wants cores and my main desktop machine doesn't have many. So I may have to buy a cheap old server system to sit in the garage to begin with.
On another problem solve, I managed to fix a small issue with triangle ray intersection tests. I noticed some issues with renders where some sections seemed to have incorrect surface colour used. I couldn't put my finger on it, but coincidentally found the problem while updating the triangle intersection test. Under some conditions, setting UV coordinates was handled incorrectly.