geometry grid randomisation

# 1 25-04-2008 , 06:07 AM

Subscriber
Join Date: Jul 2006

Location: London

Posts: 567

I was going through the 'artists guide to mel' training from dt the otherday and found the really handy little loop that can make grids of geometry.

Heres the script...

int $i;
int $j;

for ($i=0;$i<5;$i++){
for ($j=0;$J<5;$j++){

polyCube;
move -r (2*$j)0(2*$i);
}
}

I was wondering how I would go about randomising their size on creation so that I could have random size cubes etc be produced.

Chris

Quote

# 2 26-04-2008 , 05:57 AM

Registered User
Join Date: May 2004

Location: UK

Posts: 1,991

Here you go Chris, slightly modified code adding in a random number generator and applying it to the polyCube command to set the scale. Commented so people can follow it user added image

Code:

int $i;
int $j;
// holds random value assigned each time a cube is created
float $randSize;

for ($i=0; $i<5; $i++) {
    for ($j=0; $j<5; $j++) {

        // generate a random float number between 0.0 and 2.0
        $randSize = rand(2);
        // use the random number to set the cube dimensions
        polyCube -w $randSize -h $randSize -d $randSize;
        move -r (2*$j)0(2*$i);
    }
}

The only thing to remember though is that $i, $j and $randSize will be global variables which can be bad. The next step would be to change it into a function so that the variables are local.

Code:

// function that creates a 5x5 grid of randomly sized cubes
proc generateVariedCubes() {
    int $i;
    int $j;
    // holds random value assigned each time a cube is created
    float $randSize;

    for ($i=0;$i<5;$i++){
        for ($j=0;$j<5;$j++){

            // generate a random float number between 0.0 and 2.0
            $randSize = rand(2);
            // use the random number to set the cube dimensions
            polyCube -w $randSize -h $randSize -d $randSize;
            move -r (2*$j)0(2*$i);
        }
    }
}

// call the function
generateVariedCubes();

Once you've run the function code then you wont need to rerun it for the current maya session. You can therefore run the generateVariedCubes() call whenever you want or multiple times and it will create the cubes.
As an exercise it'd be good to modify the function so that it generates another set of cubes to the right or left of the previous one. Up to you though user added image

Simon

Examples of bTraffic - a traffic animation tool for Maya
bFlocking - a tool for Maya 8.5+ to generate flocking and swarming behaviours
Jan/Feb Challenge 2007 Entry and W.I.P
May/Jun Challenge 2006 Entry and W.I.P
Mar/Apr Challenge 2006 Entry and W.I.P
Jan/Feb Challenge 2006 Entry and W.I.P
Nov/Dec Challenge 2005 Entry and W.I.P
Sep/Oct Challenge 2005 Entry and W.I.P
Jul/Aug Challenge 2005 Entry
www.flash-fx.net

Quote

# 3 04-05-2008 , 10:48 AM

Moderator
Join Date: May 2005

Location: Manchester Uk

Posts: 6,300

Hey Si

Ive not used ramdom in MEL, is it actually random so to speak (say in delphi you set a random number and unless you set the clock its always the same as its always produced in the same clock cycle)??

Like I say I've never used it so cant comment.

"No pressure, no diamonds" Thomas Carlyle

Quote

# 4 05-05-2008 , 03:58 PM

Registered User
Join Date: May 2004

Location: UK

Posts: 1,991

Hi Steve,

It gives a different result each time so can be called random. If you look into how it is seeded then with some hardcore maths it might be possible to predict the variance but thats way over the head of us mere mortals user added image

Simon

Quote

geometry grid randomisation

Posting Rules Forum Rules

Similar Threads

Topics

Free Courses

Full Courses

VFX News