I know this is not the easiest way yo draw a sierpinsky triangle, but I want to get used to transformations and I think that this is a good way to make diferent fractals with about the same code.

 

I don´t know why this code doesn´t work and it says that there are too much  recursion. I see that is very limited. I think this is the standard way to draw fractals

 

void setup(){
 size(800, 800, P3D); 
}

float side = 400;
int maxlevel=2;

void draw(){
  float r=0.5;
  float a=0;
  float b=0;
  float h=0;
  float k=0;
 
translate (side,side);
rotate (PI);
triang(side);
subtriangles(1);

noLoop();
}

void transform(float r, float a, float b, float h, float k){
  translate(h, k);
  shearX(a);
  shearY(b);
  scale(r);
}
void back(float r, float a, float b, float h, float k){
 
  shearX(-a);
  shearY(-b);
  scale(1/r);
  translate(-h, -k);
}

void triang(float side){
  line (0,0,side*cos(60*2*PI/360),side*sin(60*2*PI/360));
  //println (400-400*cos(60/(2*PI)));
  line (side*cos(60*2*PI/360), side*sin(60*2*PI/360), side , 0);
  line (side , 0, 0, 0);
 
}
void subtriangles(int level){
  println(level);
  transform( 0.5, 0, 0,0,0);
  triang(side);
    if (level < maxlevel){
      subtriangles(level+1);
    }
  back( 0.5, 0, 0,0,0);
  transform(0.5,0,0,200,0);
  triang(side);
    if (level < maxlevel){
      subtriangles(level+1);
    }
  back( 0.5,0,0,200,0);
  transform(0.5,0,0,100,200*sin(60*2*PI/360));
  subtriangles(level);
    if (level < maxlevel){
     
      subtriangles(level+1);
    }
  back(0.5,0,0,200,0);
}