clicking on IRREGULAR 3D shape

Programming Questions

nsci_1t0

clicking on IRREGULAR 3D shape

in Programming Questions • 2 years ago

Hi,

Is there a way to click on 3D shapes drawn using beginShape() and endShape()?

I am drawing some shapes using beginShape(QUADS) and vertex(x, y, z) and want to be able to select the shape afterwards. Is this possible?

Thanks

EDIT: I realize you there are libraries for helping click shapes such as boxes and spheres, i.e. http://code.google.com/p/processing-picking-library/ but as far as i know it doesn't work for irregular shapes drawn with beginShape() and endShape() -- or does it??

Replies(3)

tfguy44

Re: clicking on IRREGULAR 3D shape

2 years ago

Yes, that library does exactly what you want.

When I wrote the code that initially inspired it, I wrote it not as a library but as a separate "tab" of code that works based on the color seen on a second, unseen screen. Objects on the second screen are colored based on their ID (instead of based on the fill/stroke color). The original code is still online ( http://www.openprocessing.org/visuals/?visualID=7707) if you'd like to see it.

Antiplastik just adapted the same method, but in a library form.

EDIT: Just pulled up the original code and tested it with beginShape(), vertex(), and endShape()... it works like a charm. :-)

EDIT2: Also pulled up the code for the original example of how to use the library ( http://www.openprocessing.org/visuals/?visualID=7881). It also works fine with calls to beginShape(), vertex(), and endShape(). You're in luck!

nsci_1t0

Re: clicking on IRREGULAR 3D shape

2 years ago

sweet! thanks for the response!

I had realized the picker worked for simple beginShape(), vertex(), and endShape() but for some reason it didn't work in my sketch.

It turned out it was because i had it in something like this:

beginShape()

for (int i = 0; i < x; i++){

picker.start(i);

//draw verticies...

}

endShape(CLOSE);

The picker wasn't working properly, and it turned out it was because the variable i doesn't exist outside of the for loop. I fixed it simply by creating a separate variable:

int curr = 0;

beginShape()

for (int i = 0; i < x; i++){

picker.start(curr);

//draw verticies...

curr++;

}

endShape(CLOSE);

so the next person doesn't waste hours on this

cedrickie..

Re: clicking on IRREGULAR 3D shape

2 years ago

there is also a post in the wiki about this topic
http://wiki.processing.org/w/Picking_with_a_color_buffer

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