The lighting is super crappy, and pretty much hacked in. Will
need to redo this properly soon. However, this verifies that
certain other parts of the code are (mostly) working properly.
The part of the renderer responsible for light transport has been
split out into a LightPath struct. Also moving over to spectral
rendering, although it's a bit silly at the moment.
BVH traversal still happens in local space, but final actual
surface intersection calculations are done in world space by
transforming the triangle into world space. This is to improve
numerical consistency between intersections.
This, of course, depends on the simd ops being there, which
currently they are not. But in the future, hopefully this will
make things speedy. Will need to test, of course.
This is mainly just to make the tracer code read more cleanly.
All of the pushing and popping logic obscured the big picture
and made things a bit confusing.
The test scene isn't rendering properly, presumably because
something isn't correct in the parsing (although it's not clear
it's in the mesh parsing). Need to investigate.
The AssemblyBuilder is responsible for collecting the data needed
to actually create an Assembly. AssemblyBuilders are now the
only way to create an Assembly, which guarantees that Assemblies
aren't half-baked.
Also got instancing working with transforms and such. It may not
be _really_ working because I don't have a complex test case for
it yet. But that will come later.
Apparently this is what UnsafeCell is for, and the code I wrote
before wasn't technically correct, even thought it worked in
practice. Hooray for doing things properly!
Includes:
- More scene parsing code. Making good progress!
- Making the rendering code actually use the Scene and Assembly
types.
- Bare beginnings of a Tracer type.
Weird, to be frank. It was a lot of work. Can't believe I don't
even remember doing it before. Oh well.
In any case, I've improved the 'old' one quite a bit. It should
be more robust now, and will provide errors that may actually be
useful to people when a file fails to parse.
Everything is done with indices anyway, so there was no reason
for it to store an internal reference to the object data. This
gets rid of the type parameter and lifetime parameter on the BVH
struct itself, which will also make it easier to bundle it with
the data it indexes, which will be important later on.
