Sort Sop - Sort By Expression

[Vormav]

I have come across a case where it would be useful to sort my vertices based on the angle between either the x, y or z axis, and the edge formed by the vertice and some center point (usually (0,0,0)). In other words, vertices would be sorted in a circular pattern, so that I could safely pass a range of these vertices off to an Add SOP to get a new, clean poly.

Shouldn't be too big of a deal. I created a function that, given an axis to work off of, a center point, and the other point (the point being evaluated for the sort sop), returns that angle as a floating point number.

The part where I think I'm getting mixed up is with how I'm passing along each point in the sort expression to my function. Right now, I'm trying to pass the data into the expression using point(".", $PT, "P", 0), but is $PT the right variable to be using within the context of the sort expression?

[stevenong]

Yep, $PT is the right variable to use in the point() function.

However, your expression needs to be modified as you can't call a point() onto the SOP itself. You have to reference an input SOP or other. For example, point("../input_SOP",$PT,"P",0)

Cheers!

steven

[sibarrick]

The way you have it that expression, with steven's modification will just return the x position of the point, if you want it to use the attribute you have created you'd need to change "P" for your attribute name.

[Vormav]

The world space position was actually I really needed. The problem Steve mentioned definitely was why I wasn't seeing any results though. Works perfectly now. Thanks.