The design of framework references "Realistic Ray Tracing" by Peter Shirley and R.
All images (512x512) are adaptive sampleing with 2 levels of subdivision,
with Hall illumination model
Here is the first refraction image I got. There are two spheres, two boxes and a bunny
in the image.
The green sphere is reflective, the yellow(diffusion color and specular
color) sphere is refractive.
I use the strength of light ray to control recursion.
When internal refraction happens, I choose the direction of the refracted ray to be the same as the direction of the incident ray.
Running time: 4 + 12 seconds
After I changed the red box to a red cow and the violet box to a violet penguin. I
also changed the yellow color.
I made the cow reflective, the bigger sphere refractive. The green sphere is
Running time: 286 + 1438 seconds
In this image, everything but the bigger sphere is reflective. The bigger sphere is refractive.
Running time: 362 + 2301 seconds
Here's one image I made the bunny refractive, others reflective. I rearranged the objects a
little bit, too.
Running time: 250 + 2140 seconds
Compared with ray tracing part, the adaptive sampling part is really slow. I didn't come up
with a more efficient way of doing the sampling earlier.