06-16-2006, 04:49 PM
Hi --
I'm trying to use the following expression in the AFC of my z-rotation:
(radToDeg(atan(comp(PposW,1)*pow(comp(PposW,0),-1))))*pow(360,-1)*100
(Is there some easier way to do division than multiplying by an inverse?)
What I'm trying to do is to find the angle that a given particle makes with the axes of the xy plane, and use that theta angle in my AFC (hence the normalization to 100), with my high and low values 360 and 0 degrees respectively. The ultimate effect is that I want my stretched particles to orient themselves roughly circularly, to make it look kinda vortexy. I'm using a swirl operator already, and that helps, but I really need the extra stretch for my system to look right. The problem is that it doesn't do what I want it to. the puffs seem to be rotating only in 90 degree increments, instead of continuously. Here's a quick test:
![[Image: rotation.jpg]](http://www.trentschindler.com/rotation.jpg)
Does anyone have an idea what might be going on? Could it have something to do with how max handles standard angles in arctangents?
Thanks!
Trent
I'm trying to use the following expression in the AFC of my z-rotation:
(radToDeg(atan(comp(PposW,1)*pow(comp(PposW,0),-1))))*pow(360,-1)*100
(Is there some easier way to do division than multiplying by an inverse?)
What I'm trying to do is to find the angle that a given particle makes with the axes of the xy plane, and use that theta angle in my AFC (hence the normalization to 100), with my high and low values 360 and 0 degrees respectively. The ultimate effect is that I want my stretched particles to orient themselves roughly circularly, to make it look kinda vortexy. I'm using a swirl operator already, and that helps, but I really need the extra stretch for my system to look right. The problem is that it doesn't do what I want it to. the puffs seem to be rotating only in 90 degree increments, instead of continuously. Here's a quick test:
Does anyone have an idea what might be going on? Could it have something to do with how max handles standard angles in arctangents?
Thanks!
Trent