Make the material system physically correct about c-ray

[vkoskiv]

Currently, the material system is not quite physically correct.

You are absolutely right. In the past my priority has been what looks 'good enough', often with a rather lax definition of 'good enough'. It is about time we start putting an emphasis on physical correctness, so it's great that you pointed this out!

It's doubly-awkward that the material system is flawed when literally the first thing the README says is:

C-ray is a research oriented, physically accurate rendering engine built for learning.

Oops! 😅

The current set of materials, and in fact the entire material system has been inadequate for quite a while now. So a rework of these materials could be combined with an effort to improve the material system as a whole, perhaps with a simple node-based approach.

If you want references on the topic, I can recommend PBRT.

I actually own a physical copy! But as you can probably tell, I haven't put it to good use yet.

And yes, I would very much love to talk on Discord! You can find me at vkoskiv#3100 there.