Cycles Experiment: Pinhole Camera
How physically accurate is Cycles? Ben Simonds performs a baffling experiment. Anyone up for a double-slit setup? Hah :)
Ben writes:Not much to look at is it? But it was an interesting experiment. The idea was to push cycle’s physical realism to the absurd extreme of building a pinhole camera in blender. A pinhole camera has no lens or aperture, instead the light just passes through a small hole in the front of the camera, and forms an inverted image on the camera’s back wall (this is why the image above appears upside-down). The construction of a pinhole camera is very simple – it’s a box with a hole in one side, so I figured that because Blender now has a physically accurate ray-tracer in the form of Cycles, it was probably possible to build one that worked in blender.
Link
Has anyone tried refracted light through a prism. I tried this in cycles early stages and was unsuccessful. I would also like to know if anyone has tried assembling a laser?
Light refraction is possible and easy but the laser will be insane to render as long as cycles isn’t bidirectional! :(
I managed to render this in luxrender:
http://olliakras.com/random/prism2.png
No point trying this in cycles, there’s no spectral dispersion nor bidirectional rendering.
What???
How does it do that?
The white light is just represented as an RGB value, no? So how can the renderer possibly know the spectral content of the white light?
Does it just assume that the spectral content of any light-source is roughly that of a black-body spectrum?
Colors are represented by 3 values (red, green, and blue in RGB color mode), white light is a max-value of all these colors, so a prism can split these values out based on different factors (angle, refraction index, etc).
How far away is the Cycles codebase from being able to incorporate spectral dispersion, is it just an extra step or is it an entirely different form of raytrace that is incompatible with the Cycles model at its core?
There’s many different spectra of light that to us could appear white.
An RGB value only tells us what the light looks like, and not its spectral content – but you need to know this in order to produce a proper colour dispersion pattern with a prism.
That is pretty kick ass.
nice!
here is a little trick you do not have to set the lights extremly high:
http://dl.dropbox.com/u/24502052/Blender/analog_camera.blend
just take a look at the material of the “film” ;)
Impressive. What happens when the same thing is attempted with the internal renderer?
Just curious–Cycles is physically-accurate? I thought I read a while back somewhere that Cycles wasn’t truly physically-accurate, but more a clever cheat of realistic simulation (more like something physically-semi-accurate)? Has Cycles since become physically-accurate, or has it always fundamentally been? Anyways, interesting experiment!
well, it’s not spectral, so it’s not phisically acurate
Very awesome! longer exposure through composeting frames???
Tried the double slit, simply edited the pinhole camera to have 2 slits instead of hole and did some lighting adjustment so it wouldn’t wash out.
The result was a bit disappointing,
[IMG]http://img.photobucket.com/albums/v502/wasam/blender/untitled.png[/IMG]
http://img.photobucket.com/albums/v502/wasam/blender/untitled.png
I would have been VERY surprised if it would simulate the quantum properties of photons ;-)
I can confirm Your surprise. For computergraphics it is very unusual to model diffraction effects in rendering algorithms. However in room acoustics similar algorithms like raytracing are used. As the wavelength of sound is usually much longer, it seems necessary to modify acoustical raytracing algorithms so that they can handle diffraction. Thats a topic of actual research.
Doh, I was trolled!
This is simply fascinating!
Young’s double slit experiment in cycles, how cool a thought!