$HIP : path of where current houdini file is located at.
centroid explanation:
centroid usage:
| centroid(<SOP path>, <dimension type>) | Returns the X, Y, or Z position of the center of the bounding box. “dimension type” can be one of these:
D_X, D_Y, D_Z
|
great references for beginner houdini users (#me): https://www.andynicholas.com/?p=1344&cpage=1
19/4/18
$OS (need to be in CAPS): operator string. contains current operator's name
