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September 28, 2010at9:42 pm AS3.0, English, Experimentals, flash, pixelbender, source, 4 Comments
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Laboratory output n°74 RaySlime
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377

RaySlime
RayTracing

I wanted to post these ‘oldies’ to get them into my gallery. They are raytraced balls and some slimy turds in 1×1 pixels with decent framerate. I used Pixel Bender to create them. I haven’t done much experimenting because of two reasons.

1. I’ve been coding a lot of Objective-C lately. It felt easier to return coding with whole different language. It’s still sometimes a bit frustrating to code AS3. I do typos for example with ‘<>‘-marks and with some sort-cuts but when it comes to iPhone SDK I learned new way of typing. I also want to point out that the development tools of Apple are excellent. I should get my first App out very soon.

2. I joined the Away3D group to help them with new extremely secret project. I have nothing more to say about that yet :)

Lastly here are few Pixel Bender tricks for you:

How to create a loop in Pixel Bender?
– With help of clever brains of @MrKishi = http://www.simppa.fi/source/LoopMacros2.pbk

How to make your #define’s readable?
– with “\”-mark

#define method(param) foo += param; \
                      foo *= bar; \
                      foo -= foo*0.1;

And apparently you can do like this:

#define col(b) float4(1.0, 1.0, b, 1.0);

void
evaluatePixel()
{
    dst = col(0.5);
}

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What do you think of this? (4)

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May 13, 2010at12:02 pm AS3.0, Experimentals, flash, pixelbender, 6 Comments
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Laboratory output n°73 2k Something
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377

JumpOne
RoundItGoes
click on them to view in full screen.

I’m experimenting what can be done in 2kb with flash. The Scion was also one of those tryouts. I use Pixel Bender here and it seems to be the best tool for low bytes works. Here are couple of things I figured out while playing.

You don’t need to setup the default values. Following works just fine.

parameter float z;

Also the metadata can be written like this:

<languageVersion:1.0;>
kernel a <namespace:"";vendor:"";version:1;description:"";>

The fastes way to calculate distance between two points in PB:

float2 point0 = float2(0.0,0.0);
float2 point1 = float2(1.0,1.0);
float d = length(point0-point1); //not accurate but useful enough

I’m not quite sure about this but it seems to me that it’s much faster to calculate sin(), cos(), atan() values in Flash then in PB. :) So avoid calculating same math for each pixel.

If someone knows more tricks please share.

*** [update 2010-05-14] ***

Here’s how to create a class function (sort of..)

#define calculate_something(pixel,x) pixel.r = 1.0/(x*.01);

void evaluatePixel()
{
float2 p = outCoord();
calculate_something(outpixel,p.x);
}

Here’s the way to do a loop in Pixel Bender

#define loop(res, i) res *= i;

void evaluatePixel()
{
float myColor = 1.0;
loop(myColor, 0.5); //myColor = 0.5
loop(myColor, 0.5); //myColor = 0.25
loop(myColor, 0.5); //myColor = …so on.
loop(myColor, 0.5);
loop(myColor, 0.5);
outpixel = float3(myColor,0.0,0.0);
}

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What do you think of this? (6)