This will work with TRIANGLE_STRIP or QUAD_STRIP:
stroke(0, 0, 222);
//noStroke();
//beginShape(QUAD_STRIP);
////beginShape(TRIANGLE_STRIP);
//
for (int i=0; i<listTracks.size()-1; i++) {
//beginShape(QUAD_STRIP);
beginShape(TRIANGLE_STRIP);
Track tr1 = listTracks.get(i);
Track tr2 = listTracks.get(i+1);
for (int i2=0; i2<tr1.listPVectors.size()-1; i2++) {
toolsPVector.vertexPV(GREEN, tr1.listPVectors.get( i2 ));
toolsPVector.vertexPV(GREEN, tr2.listPVectors.get( i2 ));
//toolsPVector.vertexPV(GREEN, tr2.listPVectors.get( i2+1 ));
//toolsPVector.vertexPV(GREEN, tr1.listPVectors.get( i2 ));
endShape();
}//for
}//for
Reference (nice image):
:)