ForTheScience.org

A raytracer in python – part 4: profiling

Stefano Borini — Thu, 03 May 2012 22:19:51 +0000

After having finally obtained a raytracer which produces antialiasing, it is now time to take a look at performance. We already saw some numbers in the last post. Rendering a 200×200 image with 16 samples per pixels (a grand total of 640.000 rays) takes definitely too much. I want to perform some profiling with python, [...]

NASA image shows tree density in United States

Stefano Borini — Thu, 05 Apr 2012 10:43:48 +0000

This impressive image, released a few months ago, shows the tree density in the United States (click to enlarge) According to the NASA Earth Observatory website, the map has been obtained from a variety of sources, from ground data collection to space-based radar, requiring 6 years of work. At the highest resolution, ten pixels correspond [...]

Academia StackExchange started

Stefano Borini — Mon, 05 Mar 2012 21:55:06 +0000

More than a year ago, I decided to propose a Question/Answer site for Academia on the StackExchange platform. The idea was to gather academics to share their expertise in academic career strategies, grant proposals, publication process, visa and immigration for academics, and generally all the troubles of an academic lifestyle. A few days ago, the [...]

Mountain Lion: freedom is no longer cool.

Stefano Borini — Fri, 17 Feb 2012 13:05:41 +0000

This is a rant. Here is a 10 years long Apple customer, generally satisfied with the quality of the product, but my stance started to change recently, and radically. Apple is pushing it too far. As I smelled long ago with the introduction of the App marketplace, their plan apparently is to make OSX like [...]

More jaw-dropping advances in prosthetics

Stefano Borini — Tue, 14 Feb 2012 00:11:20 +0000

I already posted about advances in prosthetics some time ago, but this is beyond words. You may want to apply the wadsworth constant to the movie.

A raytracer in python – part 3: samplers

Stefano Borini — Sun, 05 Feb 2012 01:02:47 +0000

In the previous post, we explored a very basic way of plotting images: shooting a ray from the center of every pixel, and plot the color of the object we hit. The result is a rather flat, very jagged image Border jagging arises from the fact that we are sampling with a discrete grid (our [...]

Linear algebra courses at MIT from Prof. Gilbert Strang

Stefano Borini — Thu, 05 Jan 2012 18:28:37 +0000

Linear algebra is fundamental mathematical knowledge for those who need to perform computational natural sciences. It is a neat formalism to express things in a compact way, and describe precious algorithms to solve computational problems from chemistry, physics, astronomy, and so on. I found these precious and very clear lectures from MIT professor Gilbert Strang. [...]

The third eye of the iguana

Stefano Borini — Mon, 05 Dec 2011 19:33:06 +0000

Did you know that iguanas (and not only them) have three eyes ? the feature is called Parietal eye, it is highly advantageous to spot the shadow of a predator coming from above, and it’s not unique to iguanas, but it can be found in frogs, lizards, sharks and other reptiles and fishes. In the [...]

Offsetting carbon emissions with trees: a little math

Stefano Borini — Thu, 10 Nov 2011 01:16:15 +0000

I want to do a thought experiment, hoping not to make any mistake. The world produces 29,888,121,000 metric tons of CO2 per year. According to Wikipedia, one ton of dry wood sequestrates 1.8 tons of CO2. If you put these two together, you quickly realize that you need to produce 16,604,511,666 tons of wood per [...]

A raytracer in python – part 2: rendering multiple objects

Stefano Borini — Sat, 05 Nov 2011 20:18:49 +0000

A quick addition needed to the raytracer is providing freedom to add more objects to the rendering scene. In Part 1, the design was such that only one object, a sphere, could be drawn. The new code allows much more flexibility. I added a Plane object, introduced assignment of colors to the objects, divided the [...]