[pstricks] 3d "arrows"

[Jon Joseph]

All: I have included a program which draws a "circular" arrow indicating a direction of rotation.  This is meant to demonstrate the right hand rule with the vector pointing in the z direction (as shown).  The picture looks great and was exactly what I was trying to do. However, my method is not very generalizable and if I wanted to do it again I would need to recalculate some absolute coordinates (e.g. the position of the arrow). Does any one have a suggestion as to how this type of object can be compartmentalized within pst-solides3d?  Thanks and happy new year.  Jon



\documentclass{article}
\usepackage[dvipsnames]{pstricks}
\usepackage{pst-solides3d}
\usepackage{pstricks-add}
\usepackage{amssymb, amsmath}


\begin{document}


\psset{unit=5mm}
\begin{pspicture}[showgrid=false](-5,-5)(5,5)
	\psset{viewpoint=10 30 30 rtp2xyz, Decran=30}
	\defFunction{mycylinder}(u,v){2 u Cos mul}{2 u Sin mul}{v}
	\psSolid[object=surfaceparametree,
		base=pi 2 div 9 pi mul 4 div  0 .25,
		ngrid=30,
		function=mycylinder,
		grid,
		incolor=red!20,
		fillcolor=red,
		%RotY=-10,
		action=draw**]
	\psSolid[
		object=face,
		fillcolor=red,
		incolor=blue,
		biface,
		base=0 0 .5 0 .25 .75,
		linecolor=red,
		RotY=90,
		RotZ = 60,
		action=draw**](2 sqrt, 2 sqrt, .375)
	\psSolid[
		object=vecteur,
		args=0 0 2,
		linewidth=2pt,
		linecolor=blue]
	\psPoint(0,0,2.2){A} \uput[0](A){\large $\vec{\omega}$}
	\axesIIID(0,0,0)(3,3,3)
\end{pspicture}

\end{document}