Monthly Archives: November 2013

mathimage #43: fish

Fishy fishy fishy. This time I had a small argument with the web browser. Because I wanted more from it, but it wouldn’t give it to me. Very frustrating, I wanted more instructions, to implement more maths, more sculpting, or in other words, more detail. Detail in the fish, in its movement, in its texture and colors. But the browser would crash on me every single time. So I had to give up, and simplify my code, my formulas, my shapes, or in other words, my painting. Yet, here it is, a basic swimming mathematical fish.

The body is a chain of 7 line segments thickened with a quadratic shape for the body and a rational for the tail. Colors are simple orientation and position based color patterns, and movement is a cosine for the tail and a linear + noise (cubic polynomials) for the positioning. The seabed simple combination of noise textures, and the water surface, a plane. It sort of works if you blur your eyes, I think!

The raltime version, with code/maths open for you to explore, here:


it’s that time of the year when americans start thinking of their “new year’s resolutions”. in my case, for my 2014’s resolutions, i can simply recycle those of 2013, because this last year i failed at all of them…!

another what if

When in the first security gate at the airport when they take your ID and ask you to say your first and last name, what if, just for fun, you pretend you doubt…? Has anybody tried it?

can’t avoid it

I know it’s dangerous, and irresponsible, and all… But if I’m skiing and I see a beautiful corridor between the cliffs down the mountains with some minimum amount of snow, when the warning sign says “Closed” at its top all I can read is “Go!”

a good match

it’s still a month for the christmas festivities. but the city, packed with winter motives and lots glowing lights, is already ready for them. and so is my bike as well of course.

well, she’s ready the whole year, but these days she matches the setting better than usual

ballet studios

the wooden floor, the white windows to the street, the barre, the full size mirrors, the unique smell of perspiration, and of course, the music system playing a CD by Lisa Harris…

no matter were in the world you are, such a ballet studio feels always like a magical, timeless, and a familiar space


i remember when i moved here, a mere 4 years ago, and i went to a Japanese restaurant for the first time in my life. it was such a big thing to me, so new, so strange, so different

mathimage #41: lanterns

Sometimes I like doing variations of the same (technical) idea.

In this case, I reused the technique from last mathimage, the procedural 2D regular grid acceleration structure, in order to create an infinte field of randomly sized spheres and cylinders that move and glow. There are quite a few tricks in this one. For example, the ambient occlusion is a combination of procedurally painted occlusion, and read analytical sphere occlusion (as in this article. Because of that, and because I don’t use shadow rays, I can render shadowing very, very quickly. Also, the effect of the ligthting is local to the grid cell the pixel belongs to and its immediate neighbors. So, in the end, the rendering is fast enough that I can afford some brute force depth-of-field and motion-blur.

Artistically, there’s not much to say. I improvised this in a one hour session (plus one extra for fine tuning details) in a live coding session that started with no target and steered randomly as I progressed. I called these things “lanterns” because of their vague resemblance.

As usual, feel free to click “play” to see it moving realtime in your browser, and then in the title in order to see the code/maths.

it must be awkward…

… when you are an airplane crew member and before taking off you have to go row by row checking for unfasten seatbelts, meaning, looking at the vicinity if not the exactly the center of the passenger’s packages. no wonder they overlook so many unfasten seatbelts. just saying.

not planing to get in there tonight

americans have something called “the zombie apocalypse”, that i never heard about before landing here. it’s one more of those things they have, like “the big foot”, the UFOs, God, Elvis and the nuclear holocaust.

so yes, i recently learnt what it is. and also recently, i think i found where they should start preventively looking and keeping an eye for it – in one of these laundry shops at the Tenderloin, between Geary and O’Farrel (a few blocks away from where I live):

it’s not her, it’s you

there’s this nanny in the train car taking care of a 7 years old girl, who’s joyfully jumping, dancing, and galloping all over place. she’s energetic, she’s playing, she’s happy. she’s being a 7 years old girl. which is adorable!

the nanny, in the other hand, looks disgusted and angry. she’s talking in the phone, loud, vociferously, and every 15 seconds leaves her conversation in order to shout hysterically to the girl, infuriated, asking her to stop moving around and annoying the other passengers.

what she doesn’t realize is that the only one annoying the passengers of this car is her.

sweet moments and kinematics

you are almost asleep in the car, with your head desperately fighting gravity in complete lack of stable equilibrium because your consciousness is abandoning you because it assumed that the arms of Morpheus would take over you, without realizing that even Morpheus struggles to completely embrace you with all this seat verticality and road undulations and head unbalanceness and all.

and then, that sweet moment when the red traffic light becomes green, the car accelerates and suddenly you head feels that pull backwards for a few seconds, your neck can relax, and it feels like gravity was back and not down, like if you were already horizontal. and for two seconds, it’s like all conditions and requisites are fulfilled, and you are finally ready for sleep.

but then, acceleration leads to constant velocity, and so to the regular vertical sense of gravity, as if Newton’s first law of motion kicked in to remind me that, sorry, but i won’t let you sleep yet.

i can’t wait to the next red traffic light

mathimage #40: lanscape of cylinders

Another regular-grid based rendering experiment. In this case, it’s a 2D grid though, which I use as a (procedural) acceleration structure for (procedural) cylinders. It’s pretty fast, so ast I can afford brute force supersampling for antialiasing and motion blur. Surprising.

unintended reaction?

when a restaurant hangs “2012 certificate of excellence” in their walls… i am guessing they feel very, very proud of their achievement, and hence they want to show off and gain their customer’s confidence. or something. but being 2013, what crosses my mind instead is, “what did you guys do this year worth being downgraded to a regular a restaurant in 2013?”…

i’m sorry…

what if

what if i watered my plants with orange juice?

the internet says that it might kill the plant, or it might it help grow stronger, depending on the type of plant (and type of orange juice i assume)

but no worries everybody, i’m not trying it.

thing is i was walking by the living room with my orange juice in my hand, and i realized i hadn’t watered the plants in a few days, and the connection of ideas just happened