I've gotten this to work, but the calculation time is really bothering me, since I need to add fields and other things to bring a little more motion to the particles. Playback is ridiculous in Maya and playblasts for 30 or 40 frames take around 20 minutes. Does anybody know a different / faster way to base the emission rate using ratePP on the alpha of a texture?
Here's where I'm at :
$vtxCount = polyEvaluate -v pPlane1;
for ($i = 0; $i < $vtxCount[0]; $i++) {
$vtxName = ("pPlaneShape1.vtx[" + $i + "]");
$uvSel = polyListComponentConversion -fv -tuv $vtxName;
$uvPosition = polyEditUV -r false -q $uvSel[0];
$alpha = colorAtPoint -o A -u $uvPosition[0] -v $uvPosition[1] ramp1;
if ($alpha[0] > .9) {
setAttr pPlaneShape1.emitter1RatePP[$i] 10;
}
else {
setAttr pPlaneShape1.emitter1RatePP[$i] 0;
}
}