Path tracing.

For the main loop I decided to use path tracing as the most simple and more or less acceptable solution. So, now I'm working on it.
The bidirectional path tracing appeared to be not so easy to implement. I just could not find enough description and formulas for it. Anyway, I can implement it later, it's not so important for now.
So I'm working on the basic path tracing.

SBCL, CLISP, CMUCL.

I spend already two or three days trying to run EMACS+SLIME+SBCL under my WinXP and Vista Home.
So eventually I found that I use AMD Athlon64 processor. That means for example that SBCL 1.0.19 doesn't work but SBCL 1.0.13 does. So I switched to SBCL 1.0.13.
I also use "Ubuntu+CMUCL+EMACS+SLIME" for this task (under virtual machine).

Simplification.

So I added packages into the project.
And this feature added one unexpected problem: the code seems to be slower. Much slower. Even after compilation. Anyway, the optimization will be done a little bit later.

Books about raytracing.

So, I've got two new books:

1. 3d computer graphics. a mathematical introduction with opengl.
2. realistic image synthesis using photon mapping.

thanks to http://www.pdfchm.com/

Anyway, the information I searched for is available in these books: general ray tracing. And the second book looks interesting: I was always interested in global illumination methods at all and particular in photon mapping.

The first draft render.

So, here is the first test result.



The rendered data is:

(list
(make-t3d :v0 (make-v3d :x -3 :y 2 :z 0)
:v1 (make-v3d :x -4 :y 2 :z 2)
:v2 (make-v3d :x 1 :y 6 :z 0)
:color '"255 100 0")

(make-t3d :v0 (make-v3d :x -3 :y 4 :z 0)
:v1 (make-v3d :x 4 :y 4 :z -5)
:v2 (make-v3d :x 4 :y 4 :z 5)
:color '"0 255 0")
)

Cameras are:
(list
(make-c3d :from (make-v3d :x 0 :y -3 :z 0)
:to (make-v3d :x 0 :y 0 :z 0)
:up (make-v3d :x 0 :y 0 :z 1)
:d 5
:w-px 320
:h-px 256
:w-m 10
:h-m 8)
)

Lights were not used.