Using UDIM maps in houdini

You need to check "UDIM Filename Expansion".

Than if you have UDIM textures like "pic.1001.tif" in filename need to enter "pic.%(UDIM)d.tif".

Sierpinski_triangle

Crie um Cubo e Rode o Script com o Cubo selecionado :

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global proc int sierp(int $counter , int $max) { int $currentCounter = $counter ; if($currentCounter == $max) { return 0 ; } string $objs[]; clear($objs); $objs = `ls -sl -tr`; string $newObjsList[]; clear($newObjsList); for( $item in $objs) { string $tempArray[]; // pega Bouding Box float $bbox[]= `polyEvaluate -b $item`; // separa em elemtos float $xmin = $bbox[0]; float $xmax = $bbox[1]; float $ymin = $bbox[2]; float $ymax = $bbox[3]; float $zmin = $bbox[4]; float $zmax = $bbox[5]; //print $xmin ; //print "\n" ; //print $xmax ; //print "\n" ; // acha divisoes float $quarter = ($xmax - $xmin)/4; float $half = ($xmax - $xmin) /2; float $leftQuarter = ($xmin + $quarter); float $rightQuarter = ($xmax - $quarter); float $mid = $xmin + $half ; float $bottomQuarter = ($ymin + $quarter); float $topQuarter = ($ymax - $quarter); float $topMid = ($ymax - $half); float $frontQuarter = ($zmax - $quarter); float $backQuarter = ($zmin + $quarter); float $frontMid = ($zmax - $half); //********** CRIA CUBOS ************ //LEFT BOTTOM FRONT $tempArray = `polyCube -w $half -h $half -d $half -sx 1 -sy 1 -sz 1 -ax 0 1 0 -cuv 4 -ch 1`; move -absolute $leftQuarter $bottomQuarter $frontQuarter ; $newObjsList[size($newObjsList)] = $tempArray[0]; clear($tempArray); //RIGHT BOTTOM FRONT $tempArray = `polyCube -w $half -h $half -d $half -sx 1 -sy 1 -sz 1 -ax 0 1 0 -cuv 4 -ch 1`; move -absolute $rightQuarter $bottomQuarter $frontQuarter ; $newObjsList[size($newObjsList)] = $tempArray[0]; clear($tempArray); //LEFT BOTTOM BACK $tempArray = `polyCube -w $half -h $half -d $half -sx 1 -sy 1 -sz 1 -ax 0 1 0 -cuv 4 -ch 1`; move -absolute $leftQuarter $bottomQuarter $backQuarter ; $newObjsList[size($newObjsList)] = $tempArray[0]; clear($tempArray); //RIGHT BOTTOM BACK $tempArray = `polyCube -w $half -h $half -d $half -sx 1 -sy 1 -sz 1 -ax 0 1 0 -cuv 4 -ch 1`; move -absolute $rightQuarter $bottomQuarter $backQuarter ; $newObjsList[size($newObjsList)] = $tempArray[0]; clear($tempArray); // MID TOP FRONTMID $tempArray = `polyCube -w $half -h $half -d $half -sx 1 -sy 1 -sz 1 -ax 0 1 0 -cuv 4 -ch 1`; move -absolute $mid $topQuarter $frontMid ; $newObjsList[size($newObjsList)] = $tempArray[0]; clear($tempArray); // DELETA OBJ ORIGINAL delete $item; } $currentCounter += 1; select $newObjsList; sierp($currentCounter , $max); return 0; } sierp(0, 5);

size of vector data

// vector of pointer to T class 
std::vector<T*> animais;

// add new T instance object , into the animais vector pointer 
animais.pushBack( new T() );
animais.pushBack( new T() );

//  show size in bytes , kbytes , megaBytes 
std::cout << (animais.size() * sizeof(std::vector<T>))<<"bytes" << std::endl;
std::cout << (animais.size() * sizeof(std::vector<pessoa>))/ 1024 <<"kb" << std::endl;
std::cout << (animais.size() * sizeof(std::vector<pessoa>))/ 1048576 <<"mb" << std::endl;

Convert Bytes to KiloBytes, MegaBytes, Gigabytes

1 KB = 1024 B 
1 MB = 1048576 B = 1024 KB 
1 GB = 1073741824 B = 1048576 KB = 1024 MB


So... the formula is 

X KB = NumberOfBytes/1024
X MB = NumberOfBytes/1048576 'or X MB = NumberOfBytes/1024/1024

etc, etc.

multidimensional array and pseudo-multidimensional array

#2D array access 

#define WIDTH 5
#define HEIGHT 3

int jimmy [HEIGHT][WIDTH];
int n,m;

int main ()
{
  for (n=0; n<HEIGHT; n++)
    for (m=0; m<WIDTH; m++)
    {
      jimmy[n][m]=(n+1)*(m+1);
    }
}

#1D array access

#define WIDTH 5
#define HEIGHT 3

int jimmy [HEIGHT * WIDTH];
int n,m;

int main ()
{
  for (n=0; n<HEIGHT; n++)
    for (m=0; m<WIDTH; m++)
    {
      jimmy[n*WIDTH+m]=(n+1)*(m+1);
    }
}

REMAP function and LERP function

remap range:

double fit(double index, double old_min, double old_max, double new_min,double new_max)
{
    return new_min + (new_max - new_min) * (index - old_min) / (old_max- old_min);
}

usage :
fit(0.5, 0, 1, 10, 20);
>> 15.0
>>

LERP: 
Precise method which guarantees v = v1 when t = 1.

float lerp(float v0, float v1, float t)
{
  return (1-t)*v0 + t*v1;
}

PadZero in string Parameters Houdini

create string parameters keyframe
then edit expression

Python:
hou.node("..").name() + '_%03d' % hou.intFrame()

hou.node("..").name() : parent name 

*/ works for Integers  Floats and Strings*/ 
 '_%03d' % hou.intFrame() : pad3 decimals places  using Frame as base number    

****another method only for strings*****:

n = '4'
print n.zfill(3)
>>> '004'

HScript:

opname("..")+"_" + padzero(3,"$F") 

opname(".."): parent name 
padzero(3,"$F")  :pad3 decimals places  using Frame as base number