Archive for category: Computer Graphics

Probabalistic Models of Cognition

June 13, 2014 | Computer Graphics, Computer Science | By: Mark VandeWettering

This week began with a visit from Pat Hanrahan, currently a professor at Stanford and formerly at Princeton, where I was lucky enough to meet him. He came by to talk about probabilistic programming languages, which are an interesting topic that he and his students have made some interesting progress in solving difficult problems. I […]

Deconstructing the Classic Atari Game: Star Raiders

November 17, 2013 | Computer Graphics, My Projects, Retrocomputing | By: Mark VandeWettering

Gasp, I know. It’s been some time since I posted here. A combination of life and work events have conspired to sap me of my usual exuberant energy for the nerdy, geeky pointless topics that I usually like to post about here. But nerdy, geeky, pointless endeavors do continue (even if at a reduced pace) […]

Simple code implementing the SmoothLifeL cellular automata…

October 18, 2012 | Amateur Radio, Computer Graphics, Computer Science, My Projects | By: Mark VandeWettering

Without further ado… if you want code to implement this: You can download this this zip file. Do with it what you will.

Fourier Volume Rendering

August 12, 2012 | Computer Graphics | By: Mark VandeWettering

Three years ago, I wrote a short post about volume rendering. I always meant to follow up, because I finally sorted out the problems with generating multiple, overlapping images. Here’s a new video generated with the improved code: Fourier volume rendering is less flexible than raytracing, but it does have certain computational advantages, most notably […]

More Wisdom on LEDs…

December 7, 2011 | Computer Graphics, electronics | By: Mark VandeWettering

More important help for the budding young electronics designer: Little known fact: If you wire up an LED backwards, it actually works as a dark-emitting diode. 12/7/2011 3:38 pm via webReplyRetweetFavorite @EMSL Evil Mad Scientist Note: this also works in computer graphics quite well. Just specify a negative intensity for the light value.

Making some wallpaper with the sum of cosines…

November 2, 2011 | Computer Graphics | By: Mark VandeWettering

I was inspired by some Haskell code written by keegan, so I had to write a version of it in C. I didn’t do any animation, but I did have a lot of fun playing around with the parameters. For instance, check out the code, and how changing the value of N from 5, 7, […]

Watermarking and titling with ffmpeg and other open source tools…

April 19, 2011 | Amateur Radio, Computer Graphics, Games and Diversions, My Projects, Video | By: Mark VandeWettering

I’ve received two requests for information about my “video production pipeline”, such as it is. As you can tell by my videos, I am shooting with pretty ugly hardware, in a pretty ugly way, with minimal (read “no”) editing. But I did figure out a pretty nice way to add some watermarks and overlays to […]

Code from the Past: a tiny real time raytracer from 2000

April 12, 2011 | Computer Graphics, My Projects | By: Mark VandeWettering

Back in 2000, I was intrigued by the various demos that I saw which attempted to implement real time raytracing. I wondered just what could be done with the computers I had on hand, without using any real tricks, but just a straightforward implementation of ray/sphere and ray/patch intersection. As I recall, I got two […]

Cool Hack O’ Day: real pixel coding

April 11, 2011 | Computer Graphics, Link of the Day | By: Mark VandeWettering

The problem with working some place with lots of intelligent people is that it is increasingly hard to maintain one’s sense of superiority. Today, I tip my hat to Inigo. He has a very cool demo here, where he creates a program by creating and editing a small image in photoshop, saving it as a […]

Hershey Vector Fonts

February 28, 2011 | Computer Graphics, My Projects | By: Mark VandeWettering

Nearly thirty years ago, I remember hacking together some simple code to display graphics on a WYSE 35 terminal. The terminals supported the TEK 4014 graphics commands to draw vectors, and I found the original “Hershey Fonts”, created by A.V. Hershey at the U.S. National Bureau of Standards, and placed in the public domain. I’ve […]

Somewhere… over the (simulated) rainbow revisited…

November 1, 2010 | Amateur Science, Computer Graphics, Math, My Projects | By: Mark VandeWettering

A couple of months ago, I did some simple simulations of light refracting through raindrops in a hope to understand the details of precisely how rainbows form. The graphs I produced were kind of boring, but they did illustrate a few interesting features of rainbows: namely, the double rainbow, and the formation of Alexander’s band, […]

On random numbers…

October 6, 2010 | Computer Graphics, Programming Languages, Stupidity | By: Mark VandeWettering

While hacking a small program today, I encountered something that I hadn’t seen in a while, so I thought I’d blog it: My random number generator failed me! I was implementing a little test program to generate some random terrain. The idea was pretty simple: initialize a square array to be all zero height. Set […]

Somewhere… over the (simulated) rainbow…

August 31, 2010 | Amateur Science, Computer Graphics | By: Mark VandeWettering

A few days back, I simulated how light propagated in a single drop of water, but with a number of problems. First of all, it didn’t simulate the Fresnel equations, which describe how light is reflected and refracted at the interface between two media. This meant that in my simple model, no light is actually […]

Drawing “circles” ala Marvin Minsky…

August 9, 2010 | Computer Graphics, Computer Science, Math | By: Mark VandeWettering

In my re-reading of Levy’s book Hackers, I was reminded of an interesting bit of programming lore regarding an early display hack that Marvin Minsky did for circle drawing. It’s an interesting hack because the lore was that it was originally coded by mistake, and yet the result proved to be both interesting and even […]

Simple, reliable 2.5D photography

April 25, 2010 | Computer Graphics | By: Mark VandeWettering

I’ve been interested in techniques where amateurs can digitize images and models for quite a bit. This website percolated to the top during today’s relaxing web browsing: it’s pretty spiffy, and is interesting on a couple of fronts, not the least of which is that the author designed the gearbox for tracking a laser using […]