Now I have most of the features I wanted, at least in very early stages. There is much to do still, however the basics are in place and I’m very happy with my initial renders. Still on the to-do list:
So after spending some time writing the core of the ray tracer again here is one of the first renders with multiple bounces of light. It took 4 mins to render at 2048×2048 with 32 rays per pixel, each taking 3 bounces along the way.
Aside from simplifying the light transport calculations, I have also written a camera class, which can now project rays into the world from arbitrary positions. One thing I still want to do is abstract the code to handle material interaction, since I don’t want to hard code this.
Update:
Now that I have gotten to this point, I have identified some weaknesses in my original design for this ray tracer. Originally I was casting a perhaps 4 or so rays from the camera per pixel and when these hit a surface they cast perhaps 32 sub rays from that point. This is actually fairly shit, and makes the rendering times horribly slow. All of these values were tweak able, but I have since found that sending out 256 rays from the camera, and having each one bounce only once randomly with each hit, is a much better solution, leading to more uniform noise, faster render times, free anti-aliasing, etc.
I now plan to write a ray tracer that corrects my previous design, which should in turn simplify the code immensely. I also want to try some backwards path tracing, from the light to the camera, instead of the other way around.
Additional, control of the camera was very tricky, and basically impossible to move. I have to remedy this and create a freely positionable camera.
Will post results here soon…
Update:
That concludes this days work, time for some sleep…
Some cool updates:
Just implemented some cool upgrades.
The downside is that this is slow…. really slow…
It really means that I will have to make use of multi-core threading on the CPU very soon.
I also want to implement reflective mirrored surfaces, so I can hope to see some caustics on the ground.
Things that got implemented:
Things to work on next:
First milestone render of my offline ray tracer project, which builds upon my real time raytracer.
Here the lighting is entirely contributed by ambient occlusion.
Still on the to-do list is:
Update adds:
Bit-Hacks Pixel Dungeon 