Processing 1.0 - Processing Discourse - jumping between frames in an animated sequence

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Index › Programming Questions & Help › Syntax Questions › jumping between frames in an animated sequence

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jumping between frames in an animated sequence (Read 1024 times)

jimgiles

jumping between frames in an animated sequence
Feb 18^th, 2010, 7:30pm

This is my first Processing project, so forgive me if this is a dumb question.

I'm creating an animation where each frame consists of a series of lines and text. Each frame is pretty simple. The position of lines etc can be calculated from the frame's position in the animation sequence.

As the animation runs, a circle will move along a timeline at the base of the screen so the user can see how far the animation has progressed. I want users to be able to click on the circle and move the animation backwards or forwards.

I'm wondering how to draw each frame so that Processing can draw each as quickly as possible. I can see two options:

1. Check the position on the timeline and use that position to generate a new frame each time.
2. Draw all frames before running the animation, save each as an image and use image() to display the appropriate frame based on the timeline position.

Which method would be more likely to make the animation look smooth as the user dragged the timelines\ backwards and forwards?

Thanks!

Jim

TfGuy44

Re: jumping between frames in an animated sequence
Reply #1 - Feb 19^th, 2010, 1:08am

I'd go with option 1, considering that the frame is redrawn every time draw() is called anyway. Consider the code below. Variable xx and yy are each, essentially, frame counters for lines. Depending on where you click determines where the lines are, and when you release the mouse button they "play" through the "frames" in order.

int xx = 0;
int yy = 0;
void setup(){
size(200,200);
stroke(255);
}
void draw(){
background(0);
xx=(++xx)%width;
yy=(++yy)%height;
line(0,yy,width,yy);
line(xx,0,xx,height);
if(mousePressed){
xx = mouseX;
yy = (mouseY+height/2)%height;
}
}

jimgiles YaBB Newbies Offline Posts: 9	Re: jumping between frames in an animated sequence Reply #2 - Feb 25^th, 2010, 9:23am Thanks, TfGuy44. If the code that defines each frame were more complex, presumably there comes a point at which it is quicker to load all the frames in advance and use image() to display the appropriate one? jim

TfGuy44 Full Member Offline Posts: 209	Re: jumping between frames in an animated sequence Reply #3 - Feb 25^th, 2010, 3:56pm Presumably, yes. But that extra speed comes at the rather extreme cost of using up a lot of memory.

ekenei

Re: jumping between frames in an animated sequence
Reply #4 - Mar 6^th, 2010, 6:34pm

if your animations have somewhat of a defined end position then you could use my animation library which i post at http://processing.org/discourse/yabb2/num_1261940382.html. you can see an example of creating tweens and seeking through them using timeline class http://ekeneijeoma.com/processing/motionlib/examples/Timeline_Seek/applet/index.... or the tweensequence class http://ekeneijeoma.com/processing/motionlib/examples/TweenSequence_Seek/applet/i...

http://ekeneijeoma.com/processing/tween/

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