explorers’ club


Neato: Two Story Camping Vehicle
Thursday, January 22, 2009, 6:32 pm
Filed under: Uncategorized

I want to build one now.  Forget rent!  Check this out – link



Old School Trigonometry Tricks & Tips
Sunday, January 18, 2009, 5:01 am
Filed under: geometry, math

Note to self:

I was cleaning out some old notebooks and file and found my old TI-83 Graphing Calculator from high school (circa 1994-ish).  Inside its slip cover I found some old sticky notes with my trig tricks and tips.

The trig triangle of choice:

This triangle will be referenced by most of the tips below.

Radians to Degrees and back again:

  • radians = degrees * π / 180
  • degress = radians * 180 / π

SOH CAH TOA

  • sin ϴ = opposite / hypotenuse
  • cos ϴ = adjacent / hypotenuse
  • tan ϴ = opposite / adjacent

Subdivision of cirle in 30º increments:

  • 30º = π / 6
  • 60º = 2π / 6
  • 90º = 3π / 6
  • 120º = 4π / 6
  • 150º = 5π / 6
  • 180º = π
  • 210º = 7π / 6
  • 240º = 8π / 6
  • 270º = 9π / 6
  • 300º = 10π / 6
  • 330º = 11π / 6
  • 360º = 2π

Subdivision of cirle in 45º increments:

  • 45º = π / 4
  • 90º = 2π / 4
  • 135º = 3π / 4
  • 180º = π
  • 225º = 5π / 4
  • 270º = 6π / 4
  • 315º = 7π / 4
  • 360º = 2π

Cosine constants for common values:

  • cos 0º = 1
  • cos 30º = √3 / 2
  • cos 45º = √2 / 2
  • cos 60º = 1 / 2
  • cos 90º = 0
  • cos 180º = -1
  • cos 270º = 0

Sine constants for common values:

  • sin 0º = 0
  • sin 30º = 1 / 2
  • sin 45º = √2 / 2
  • sin 60º = √3 / 2
  • sin 90º = 1
  • sin 180º = 0
  • sin 270º = -1

Tangent constants for common values:

  • tan 0º = 0
  • tan 30º = √3 / 3
  • tan 45º = 1
  • tan 60º = √3
  • tan 90º = ∞
  • tan 180º = 0
  • tan 270º = ∞

Secant constants for common values:

  • sec 0º = 1
  • sec 30º = 2√3 / 3
  • sec 45º = √2
  • sec 60º = 2
  • sec 90º = ∞
  • sec 180º = -1
  • sec 270º = ∞

Cosecant constants for common values:

  • sec 0º = ∞
  • sec 30º = 2
  • sec 45º = √2
  • sec 60º = 2√3 / 3
  • sec 90º = 1
  • sec 180º = ∞
  • sec 270º = -1

Cotangent constants for common values:

  • sec 0º = ∞
  • sec 30º = √3
  • sec 45º = 1
  • sec 60º = √3 / 3
  • sec 90º = 0
  • sec 180º = ∞
  • sec 270º = 0

Law of Cosines:

  • a² = b² + c² – 2bc * cos α
  • b² = a² + c² – 2ac * cos β
  • c² = a² + b² – 2ab * cos γ

….formulated to solve for the cosines:

  • cos α = (b² + c² – a²) / 2bc
  • cos β = (a² + c² – b²) / 2ac
  • cos γ = (a² + b² – c²) / 2ab

Law of Sines:

Given a circle with a radius = r circumscribed around a triangle,

  • sin α / a = 2r
  • sin β / b = 2r
  • sin γ / c = 2r

and the rest that I couldn’t make sense of:

Some inversions of the advanced stuff I never use:

  • arcsec ϴ = arccos (1 / ϴ)
  • arccsc ϴ = arcsin (1 / ϴ)

Some domain, range and quadrant stuff regarding f(x) = y:

  • y = tan^-1 x:
    • Domain: all real numbers
    • Range: -π / 2 – π / 2
    • Quadrants: I, IV
  • y = cot^-1 x:
    • Domain: all real numbers
    • Range: 0 – π
    • Quadrants: I, II
  • y = sec^-1 x:
    • Domain: x ≥ 1, x ≤ -1
    • Range: 0 – π
    • Quadrants: I, II
  • y = csc^-1 x:
    • Domain: x ≥ 1, x ≤ -1
    • Range: -π / 2 – π / 2
    • Quadrants: I, IV


Quick Review: Left 4 Dead (XBox 360)
Wednesday, January 14, 2009, 4:26 pm
Filed under: Uncategorized

After my original XBox kicked the bucket, I went out and got its younger brother, the 360.  I have to say I am really impressed with it.  Seeing as I use it primarily as a DVD player, it works well.  If you add the online Netflix feature, then its the best media device I have purchased in a LONG time.  A brilliant combination.  Oh yeah, and the copy of Gear of War (#1) is pretty cool.

So being the zombie fan I am, I went out and got Left 4 Dead.  After reading the reviews and such, I thought to myself, how could I go wrong?   Everyone is raving about:

  • the graphics
  • the replay value
  • the online experience
  • the simple but scary game play which is blindingly fast
  • the atmosphere
  • the AI

What the hell are these people thinking?!?!?!  This game sucks!  Let me address the following points above now:

  • the graphics - they are just OK.  Nothing to rave about.  The fire particle effects look like they came from a Playstation One.  How the graphics handle coupled with how fast everything moves is pretty impressive.  Some nice blur effects and such.  But looking at the characters, weapons and enemies, its just swiss cheese.  I have seen better graphics on the Wii or XBox One.  I am all for a game developer focusing on fun game play rather than impressive graphics, but this lacks both for the most part.
  • the replay value – Considering the very strict linear play of each level, I would say there is a very small replay value.  Given that the 360 has the power to render HUGE maps of beautiful quality (e.g. Assassin’s Creed) why was so little thought put into these maps?  This  was one of the main reasons I bought this game was that everyone raved about the replay value.  The only thing that changes is the enemy spawn points and even that quickly becomes predictable.
  • the online experience – this is actually one of the redeeming qualities of the game, but not like it sets itself above any other game.  One good thing I saw was that if a game host leaves, someone else becomes the host so that the xbox live party can continue on without interruption.
  • the simple but scary game play which is blindingly fast – very simple and not very scary.  The endless batteries on your weapons’ flashlights provide little realism to what is supposed to be a scary situation.  Also the fact that scattered between your starting point and goal, there are just random weapons lying about.  Endless flash lights + endless ammo = a not very realistic situation = not a very scary situation.  Even when you encounter a horde of enemies, you can get hit a bazillion times and still survive.
  • the atmosphere – again not scary.  Its too well lit in most areas with an ambient fog that provides enough cues as to where enemies are coming from.  Part of the scary thing in a zombie movie to me is the sound and they put little thought into that as well.
  • the AI – this is just so so.  Your AI teammates are good about the friendly fire and they save your ass plenty of times but there is still something lacking.  Of course when you are talking zombies, you can’t really talk about AI aside from a swarm mentality which this game exhibits.

So that’s it.  If you just can’t wait to throw down $60 on the next big zombie hit, then by all means go get Left 4 Dead.  I played this smartly tho.  I went to Game Stop and got a used version of the game, so I can return it within 7 days of purchase.  Maybe I will swap it for Fallout 3 or that new Star Wars game.



as3isolib blog up and running
Saturday, January 10, 2009, 4:29 pm
Filed under: actionScript, development, flash, flex, fun stuff, gaming, geometry, isolib, math, projects

I have used this blog to post most of the updates regarding the as3isolib.  I recently got another blog just for it now.  So any future updates will be posted there, not here.

http://as3isolib.wordpress.com/