
Velocity Raptor – an adventure in 2+1 dimensions - stared
http://www.testtubegames.com/velocityraptor.html
======
TestTube_Andy
Hey there - game's creator here. I came across this post and figured I'd pop
in to say: thanks to everyone for playing! (And thanks to stared for sharing
it.)

I'm happy to answer any questions/take feedback/suggestions.

Oh, and __m: I can't reveal VR's secret identity... what if Professor Rex
found out? Could spell certain disaster.

~~~
stevenh
Since you're using Flash, have you considered using either AGAL shaders or
DisplacementMapFilter to implement relativistic aberration?

Here is a crude example I just threw together (click for focus, then use the
arrow keys to move):
[http://circlepush.com/raptor.html](http://circlepush.com/raptor.html)

~~~
TestTube_Andy
Oh, that's really cool. No, I'd not heard of those shaders or
DisplacementMapFilter - but it sure looks like they could do what I need. My
current method (as you can perhaps tell) is to split the (non-relativistic)
image into a bunch of thin triangle fanning out radially from your character,
then redraw those images onto triangles with modified angle/vertices.

It works pretty well, but I imagine using one of the methods you listed would
be a lot faster. Thanks for sharing them, I'll keep them in mind for a
possible upgrade to the game.

~~~
stevenh
I'm a bit embarrassed to admit I didn't realize you'd already solved this,
because I hadn't played all the way until level 25 the first time around. Your
method looks fantastic.

~~~
TestTube_Andy
Oh - haha - no problem. One of my favorite parts of watching people who know
about relativity play this game is seeing them a) think of an effect that
isn't shown in the game, and state that out loud, then b) reach the level that
the effect is introduced. (Doppler shift, aberration, etc.) Makes me smile
every time.

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stared
For another game on special relativity, there is A Slower Speed of Light
([http://gamelab.mit.edu/games/a-slower-speed-of-
light/](http://gamelab.mit.edu/games/a-slower-speed-of-light/)), which is
(also) very realistic: [http://physics.stackexchange.com/questions/43695/how-
realist...](http://physics.stackexchange.com/questions/43695/how-realistic-is-
the-game-a-slower-speed-of-light).

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stared
And a list of such science-based games, which I am constantly expanding:
[https://hackpad.com/Science-based-
games-J0X4MSberlM](https://hackpad.com/Science-based-games-J0X4MSberlM)

~~~
justifier
whether considered a game could be debatable..

this cern based incremental game is wondrously full of great research that the
player discovers through perseverance :

[http://particle-clicker.web.cern.ch/particle-clicker/](http://particle-
clicker.web.cern.ch/particle-clicker/)

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arikrak
Nice game. I think lots of concepts can be taught with these types of games. A
physics quibble - should the raptor be able to stop instantaneously, even when
moving right near the speed of light? Shouldn't slowing down happen over time
just like speeding up? I'm asking both from a newtonian physics perspective
and as a way of showing how time changes during the deceleration.

~~~
TestTube_Andy
Thanks for playing. It's an interesting question about the huge-and-
instantaneous acceleration when the raptor stops. The way I treated it when
making the game was that the spacebar is equivalent to applying an
acceleration exactly equal to (minus) your speed divided by the timestep of
the game. Which means from one frame to the next you'll go from moving to
stopped.

So from a technical perspective, the acceleration isn't infinite, since it
happens over the course of a single frame. Of course, that reveals one of the
odd parts about having discrete time-steps (frame, frame, frame) instead of
continuous time.

Practically, the acceleration it would take to stop you _that_ suddenly would
indeed be immense, and certainly the forces would be enough to tear a normal
velociraptor's claws right off her feet. (Luckily, VR is no _normal_ raptor)

If you do want to be able to see the acceleration, you can always use the
arrow keys to slow down... or hold down an arrow key as you hit the spacebar
(that decreases the 'braking' acceleration)

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tux3
I-is that one of KSP's space music I'm hearing on the first level ?

~~~
TestTube_Andy
Yes it is. It's 'Bathed in the Light' by Kevin McLeod. He's got a nice site
(incompetech.com) filled with royalty free music. Great for low-budget game
devs like myself. Sounds like KSP picked one of the same songs I did.

~~~
tux3
Thanks for the link! That's going in my bookmarks.

Great game, by the way.

~~~
TestTube_Andy
Thanks! And no problem about the link. I'll warn you, though, once you listen
to his music, you'll start to hear it _everywhere_ in games. So listen at your
own peril :)

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spiritplumber
The Kerbal Space Program music is a little distracting, but it's a pretty
clever game!

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Tideflat
I love the game but I don't understand the exact mechanics for when I unlock a
gate. Do I just need to be near the key when it is the right colour? Because
that doesn't seem to work all the time.

~~~
bo1024
I believe you need all the keys to turn the same color as the gate,
simultaneously.

~~~
Tideflat
Thank you! Your method works.

With it I beat the game. The game really helped my understand special
relativity in a "intuitive" way.

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nsajko
I've measured the bullet speed by syncing the raptor with the bullets and it
seems that Newtonian bullets go 2 mph and relativistic ones (level 35) only
1.4 mph?

~~~
TestTube_Andy
Different cannons shoot bullets at different speeds. Check out the (bonus)
level 40 to just play around with a few different cannons at once, and see
that their speeds stay constant whichever view you select.

I wanted to let the bullets have different speeds to change the 'strength' of
the relativistic effects. For example, making the ones in level 9 move really,
really fast so you couldn't pass through them without using a little
relativistic trick.

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zem
anyone else have to stop playing due to motion sickness? it's odd; i usually
don't get that from games but this one made me feel distinctly queasy.

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__m
Is the name of the Velocity Raptor Mr. Tompkins?

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mjcohen
As in "Mr. Tompkins in Wonderland"?

~~~
__m
indeed, the game reminded me of it. Thinking again about it, the player could
also be called Mr.Tompkins.

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Geee
I can't get past level 12, because I can't pick up the key although it's
correct color.

~~~
nsajko
You don't need to pick up the key, you just need to observe it as the correct
color.

~~~
Geee
I'm pretty sure I picked it up in the previous level. How do I 'observe' it?

Edit: Seems I need to match the colors. Didn't read instructions.

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trellos
I'm curious, why a raptor?

~~~
TestTube_Andy
Either:

a) Raptors are the cleverest of animals, with an uncanny ability to understand
relativity. b) I am obsessed with Jurassic Park and couldn't pass up a good
pun.

So, you know. One of those two.

~~~
NeutronBoy
[https://xkcd.com/135/](https://xkcd.com/135/)

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neaanopri
This is quite great!

