Early camera lens attributes

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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.

The ISO and T-stop controls shown just above the render button.

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.

The image above has the problematic area circled red. May be a little hard to see on some monitors, but there's a black triangle in there that should have texture on it. This issue is now fixed.