Sunday, December 30, 2007

Obstacle-avoiding algorithm in povray

Here's an animation showing an obstacle avoiding algorithm in povray. The camera follows the path of a boid trying to negotiate its way through a maze of balls suspended in place, and follow a set path. The path goes through the red balls. The boid is supposed, of course, to avoid hitting the red ones. There is some jerkiness as it tries to decide what to do when one part of the algorithm is telling it go through the ball and another is telling it not to hit anything. Maybe there's more work to be done there.

Jittery bunch of superheroes

I found this also from years back.

It's a short animation of a team of superheroes I was putting together. The characters were uprooted from other scene files, some where they were dancing, some where they were marching, some where I took a "walk cycle" file and put only the first frame in a dramatic pose. When I just started generating images, I got this wacky concoction.

Done in povray.

Friday, December 21, 2007


I was dusting off an old CD and found this rendering. One of the few things I did in Bryce with Poser. From around 2004.

Wednesday, December 19, 2007

Lamest Winter Festival ever: Virginia Beach Festival of Lights.

Originally uploaded by pterandon.

While driving to this festival in the town square of Virginia Beach, Virginia, my host explained that there would be lights. I sarcastically said, "Oh, what are they going to do: light up the rectangular outline of some buildings?" Then I immediately apologized for being such a bitter cynic, for expecting something so lame.

Then we got to the town square of Virginia Beach. There were a few large teddy bears covered in lights, a face painting booth, and a beauty pageant winner walking around asking folks to sign Christmas cards for wounded service personnel. That's about it.

There was a musical act, a trio of local teenage girls singing. The quality of their performance would have been fine for three songs, but they went on for eight. That's the problem. In planning such an event, one ought to take into consideration an economy of crowd's patience vs. entertainment talent level. We in the crowd were happy to entertain anybody for a short time, but for it to have lasted so long, with not much else to do, tested our endurance.

Then came the finale: after the mayor's speech, Santa drove up in a car. He flipped a switch and on came the lights!

The lights traced out the rectangular outline of several buildings.

Monday, December 17, 2007

How to make a giant UFO-like tubular balloon

This was so cool when I saw what he had at the end!

Thursday, December 13, 2007

Friday, December 07, 2007

Animated GIF for Rotating Earth

An animated GIF made with povray.
It is a stack of 15 spheres, each slightly larger than the other, and slightly different pigment:
[n/max color transmit 1.0]
[n/max color mapcols(n/nmax)]
scale 0.125*1.5}

Where a is a number that goes from 0 to 1, and mapcols is a linear spline that I used to set up my colors.

Wednesday, December 05, 2007

Ellipsoidal Star Discovered

Why, it's our own sun!

Original sunset image:

Contrast adjusted:

Zoom in on sun, draw the nearest ellipse which matches its shape: an ellipsoidal star!

Tuesday, December 04, 2007

Christianity as Global Threat.

Before I talk about Brian McLaren's article, Christianity as a Global Threat, let me make an analogy. Consider the speed limit.

Consider a town where speed limit signs have been posted along the side of the road for longer than anyone in the town has lived. Folks have debated exactly who put up the signs. The signs say, "Do not drive faster than 30MPH in front of daycare centers". The drivers on the road have a variety of responses to the sign. Some hate being told what to do and so drive 50 MPH. Some drive 30 MPH, ever careful to slow down whenever they see a kid by the side of the road, because the sign reminds them about the risk of hitting children. Some drivers, however, drive 30.0 MPH, rain or shine, regardless of whether there are dogs, cats, deer, little old ladies, or children in the road in front of them.

Now in my analogy, the townsfolk start complaining about the mean drivers in the third camp. The third camp drivers say, "I believe these signs are a divine ordinance. Because of these signs, I have a divine mandate to drive 30 MPH whenever I want." Some of the townsfolk, rightly alarmed at the philosophy of this third camp of drivers, point to the speed limit signs as a source of evil, and say that whoever posted them must be a very bad person. The second set of drivers, meanwhile, get offended that a philosophy of running over kids is somehow associated with a literal reading of the stop signs, noting that there are also laws against hurting people. The second set of drivers say that the townsfolk mad about the sign are as silly as the third set of drivers who drive crazy.

McLaren points to three dysfunctions in American Christianity, which are "prosperity, equity, and security." I don't think that blame for the Prosperity Gospel, nationalism, and Bush/Falwell's view of the War on Terror can in any way be laid on a literal reading of the bible. I say folks like Martin Luther King Jr., Dietrich Bonhoeffer, and Oscar Romero are the literalists. They neither skimped on the spirituality nor remained silent when their fellow men and women were being trampled upon.

McLaren continues:
"The final conclusion of the book surprised me as much as I hope it will surprise readers: the most radical thing we can do to bring change into our lives and world, it turns out, is an act of faith – an act of withdrawing trust from the dysfunctional stories we’ve been told – stories both secular and religious, and transferring our trust to another story, a story captured by Jesus in the metaphor of “the kingdom of God.”
(Hat tip to Willzhead blog for a link to that discussion.

Here's the problem with McLaren's view. I say that belief in the old story, even a literal belief, an ardently-held belief in the old story of sin, cross, and redemption, has nothing to do with the misanthropic content of the Falwells of the world. McLaren's argument shows incredibly sloppy scholarship and it gives the bigots and torturers far too much credit. It seems to say, "Oh poor Falwell and Robertson. They are such inherently good people, they've just been duped into following some misanthropic stories, which they follow oh so faithfully in all extents. If only we could find some different stories for them to follow." Another apparent mistake with McLaren's approach is the implication that one were ardently to hold to a story, one must therefore start bopping the heads of those who disagree. Does the same apply to McLaren's story? Ouch!

KISS Becomes Old Farts

As a kid, I was something of a loser, a nerd, and a religious prude from a socially conservative midwestern family. So I was especially unpopular with the kids who talked about alcohol or drugs and whose parents let them go to rock concerts. I even half-believed in backmasking.

The rock group KISS was one of those groups that the popular kids listened to.
KISS seemed to be the epitome of rebellion against everything I believed in, starting with moderate physical appearance.

Then as I grew older, I became more socially progressive. My "social justice" views also influenced my opinion of the struggle of the RIAA against those who download music. I strongly support private property rights and so oppose illegal file sharing, but know that musicians are horribly exploited. The RIAA is on the wrong side of justice but the most effective way to fight them involves diverting our entertainment dollars to companies that pay fair royalties: magnatune, beatpick, etc.

Anyway, now it looks like KISS has become old farts, now looking to "The Man" to protect their nickel at any social costs. Or maybe there's no change. Naked self interest back then and now. I have quoted below interesting excerpts from Billboard magazines' Billboard Q&A: Gene Simmons
It has been nine years since we've seen a new KISS album. Any plans to get back into the studio?
The record industry is in such a mess. I called for what it was when college kids first started download music for free -- that they were crooks. I told every record label I spoke with that they just lit the fuse to their own bomb that was going to explode from under them and put them on the street.

There is nothing in me that wants to go in there and do new music. How are you going to deliver it? How are you going to get paid for it if people can just get it for free? I will be putting out a Gene Simmons box set called "Monster" -- a collection of 150 unreleased songs. KISS will have another box set of unreleased music in the next year.

The record industry doesn't have a f*cking clue how to make money. It's only their fault for letting foxes get into the henhouse and then wondering why there's no eggs or chickens. Every little college kid, every freshly-scrubbed little kid's face should have been sued off the face of the earth. They should have taken their houses and cars and nipped it right there in the beginning. Those kids are putting 100,000 to a million people out of work. How can you pick on them? They've got freckles. That's a crook. He may as well be wearing a bandit's mask.

Doesn't affect me. But imagine being a new band with dreams of getting on stage and putting out your own record. Forget it.

But some artists like Radiohead and Trent Reznor are trying to find a new business model.
That doesn't count. You can't pick on one person as an exception. And that's not a business model that works. I open a store and say "Come on in and pay whatever you want." Are you on f*cking crack? Do you really believe that's a business model that works?

Gene, does the RIAA model work for new bands? for Billy Joel?

Monday, December 03, 2007

Randomized Povray guys

Not sure what I was expecting from this ...

Sunday, December 02, 2007

St. Augustine on Waterboarding

"Even when a city is enjoying the profoundest peace, some men must be sitting in judgment on their fellow men. Even at their best, what misery and grief they cause! No human judge can read the conscience of the man before him. That is why so many innocent witnesses are tortured to find what truth there is in the alleged guilt of other men. It is even worse when the accused man himself is tortured to find out if he be guilty. Here a man still unconvicted must undergo certain suffering for an uncertain crime-- not because his guilt is known, but because his innocence is unproved. Thus it often happens that the ignorance of the judge turns to tragedy for the innocent party. There is something still more insufferable-- deplorable beyond all cleansing with our tears. Often enough, when a judge tries to avoid putting a man to death whose innocence is not manifest, he has him put to torture, and so it happens, because of woeful lack of evidence, that he both tortures and kills the blameless man whom he tortured lest he kill him without cause. And if, on Stoic principles, the innocent man chooses to escape from life rather than endure such torture any longer, he will confess to a crime he never committed. And when it is over, the judge will still be in the dark whether the man he put to death was guilty or not guilty, even though he tortured him to save his innocent life, and then condemned him to death. Thus, to gather evidence, he tortures an innocent man, and lacking evidence, kills him."

St. Augustine, The City of God, Book XIX, Chapter 6, pp. 444-445.