Runtime Error (2)

[user_deleted]

Hi All

I am experimenting with MEL driven particles. Nothing complex, its more to learn how to apply what I am learning in my mechanics lessons to Maya.

I have an expression that follows a simple path defined by a sin(time) function and then at certain values of the function creates some cubes which should be moved to the position at which that value was produced.

When I run it though I get this runtime error on the move line.
The cubes are created but not moved.

// Error: line 21: Error while parsing arguments. // 

// Error: An execution error occurred in the runtime before dynamics expression for basePartShape. // 

Here is the expression

$tsin = sin(time);

$t = $tsin*20;

vector $pPos = <>;

basePartShape.position = <>;

$pPos = basePartShape.position;

print( "Position" + $pPos + "\n");

print( "$t _ " + $t + "\n");

print("Sin(time)" + $tsin + "\n");

print ("\n pPos x" + $pPos.x + " \n");

if (($tsin <= 0.9) && ($tsin >= 0.8)) {

print("\n TRUE \n");

} else {

print("\n FALSE \n");

}

if (($tsin <= 0.9) && ($tsin >= 0.8)) {

//particle -p $pPos;

polyCube;

move -a $pPos;

}

 Does anyone have any ideas about this?

Thanks
Dave 

[joojaa]

Yeah you don't want to do this. Anyway your not using mel to drive the particles your expression is doing it its just executing mel in the process. But the bulk of the work is actually done by the node. So saying you use mel to drive the particles is a bit like saying. That once you spray paint a boat with a text the text is moving the boat (but certainly it may affect the boats behavior but its not the motive force).

expression != mel

This is actually the 3rd most usefull thing you can learn about maya one you get WHY theres a big difference youll understand maya much better. 

if (($tsin <= 0.9) && ($tsin >= 0.8)) {
  //particle -p $pPos;
  polyCube;
  move -a $pPos; <- Error!
}

the synax of move is move [flags] float float float [objects] So you need to type:

move ($pPos.x) ($pPos.y) ($pPos.z)