Processing 1.0 - Processing Discourse - makingThingsMove (animation via code)

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makingThingsMove (animation via code) (Read 2066 times)

zach

makingThingsMove (animation via code)
Oct 15^th, 2005, 1:52am

hi all,

as part of a workshop I did in madrid (at the medialab madrid), in june, I created a series of processing sketches to explain the basic principles of programmatic animation.

I've posted the processing sketches here:

http://thesystemis.com/makingThingsMove/

You can download code examples from day 1, 2 and 3.

I'm hoping to find some more time soon to write about how these examples work and how they fit together.

In the meantime, I hope you enjoy this collection of processing sketches from that workshop.

- zach

Arkitus YaBB Newbies Offline Posts: 32	Re: makingThingsMove (animation via code) Reply #1 - Oct 19^th, 2005, 12:01am Very nice work. I like the way you have grouped almost all of the animation techniques into similar sketches. I'm sure it will be useful for a lot of people. One thing I would suggest is adding a framerate cap to the sketches. Ali
	Personal Website: http://www.arkitus.com

zach

Re: makingThingsMove (animation via code)
Reply #2 - Oct 21^st, 2005, 9:38pm

interesting, would that be using the framerate(fps) function or rolling something myself using a timer (ie sleep or don't sleep)...

Another option, which I didn't get to in the code examples, is using framerate independent motion, ie timesteps "idle(dt)" are based on the actual time not the frame. good game programmers know this well, and it might be the best approach - ie, render as fast or as slow is you want, but move the objects based on actual time, not frame rate.

Arkitus YaBB Newbies Offline Posts: 32	Re: makingThingsMove (animation via code) Reply #3 - Oct 22^nd, 2005, 11:25pm Yeah, I know what you mean about time vs framerate. What I had in mind was a simple framerate(30); statement in setup().
	Personal Website: http://www.arkitus.com

AxiomShell YaBB Newbies Offline Posts: 4	Re: makingThingsMove (animation via code) Reply #4 - Nov 18^th, 2005, 7:53pm cool. simple and nice.

watsoncj

Re: makingThingsMove (animation via code)
Reply #5 - Dec 17^th, 2005, 7:36am

Zach,

Very nice code examples. I played with the vector fields for hours! They appear to be a very powerful data structure.

I've been looking at example_06_02. I've seen this variable "float pct" in a few other examples. What does this name stand for? What is it doing?

Hoora for polymorphism!

Casey

Quote:

void calculateForces(){

vec2d dist = new vec2d(0,0);
float radius = 30.0f;

for (int i = 0; i < numParticles; i ++){
if (PRTS[i].bAlive == false) continue;
for (int j = 0; j < i; j ++){
if (PRTS[j].bAlive == false) continue;

dist.set(PRTS[i].pos);
dist.sub(PRTS[j].pos);
float len = dist.length();
if (len < radius){
float pct = 1.0f - (len/radius);
dist.normalise();
dist.mult(pct * 0.05f); // scale the force!

PRTS[j].vel.add(dist);
PRTS[i].vel.sub(dist);
}
}
}
}

zach

Re: makingThingsMove (animation via code)
Reply #6 - Dec 25^th, 2005, 5:06am

watsoncj wrote on Dec 17^th, 2005, 7:36am:

I've been looking at example_06_02. I've seen this variable "float pct" in a few other examples. What does this name stand for What is it doing

thanks!

sorry for the delay, I don't get an email when there is a response...

pct is a number which goes from 0 to 1, this could be anything, but as a rule for myself, it represent a value of 0 to 1. for example, you could convert mouse position in x to a pct,

float pct = mousex / width;

in this case pct is a number which represent how close the objects are. this is based on their actual distance (dist) devided by the whole (in this case 30.0f). As the distance gets closer (the object get closer to touching each other) this number gets closer to 0. I inverted it, by subtracting it from 1...

float pct = 1 - (dist/radius);

when dist is close to radius, ie 28, the number is small

1 - ( 28 / 30 )

when dist is close to zero, the number is larger

1 - ( 3 / 30 )

I use this number (pct) to scale the forces on these two objects, when they are closer, apply more force, when they are further away, apply less force.

hope that helps - feel free to ask some more if it's not clear....

- zach

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