<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Again, I am trying to create a macro to draw three level sets of the function (x^2+y^2)/A^2+z^2/B^2,<div>one for a positive value (say, =1), one for zero, and one for a negative value (say, -1).</div><div><br></div><div>I have successfully created macros to draw each of the three levels separately, with an optional argument for "action",</div><div>the default being "action=draw**". (Code for these is copied at the bottom of this message).</div><div><br></div><div>Now I am trying to combine the three macros to create a single picture.</div><div>The following code draws all three, but of course since they are unrelated graphic objects the appropriate hiding does not occur:</div><div><br></div><div><blockquote type="cite"><div><font class="Apple-style-span" color="#000000">\begin{pspicture}(-5,-6.5)(3,6.5) </font></div><div><font class="Apple-style-span" color="#000000"><br></font></div><div><font class="Apple-style-span" color="#000000">\psset{unit=0.75}</font></div><div><font class="Apple-style-span" color="#000000">\psset{lightsrc=50 -20 50, viewpoint=20 -0.1 30 rtp2xyz,</font></div><div><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000"> </font></span><font class="Apple-style-span" color="#000000">Decran=50}</font></div><div><font class="Apple-style-span" color="#000000">%\psset{solidmemory}</font></div><div><font class="Apple-style-span" color="#000000">%</font></div><div><font class="Apple-style-span" color="#000000">\cuthyperboloid{0.5}{1.0}{4}{20}{20}{gray!85}{gray!45}{4}</font><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000"> </font></span></div><div><font class="Apple-style-span" color="#000000">\cutcone{0.5}{1.0}{3.6}{20}{20}{red!65}{red!15}{2}</font><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000"> </font></span></div><div><font class="Apple-style-span" color="#000000">\hyperboloidtwosheet {0.5}{1.0}{1.8}{20}{20}{blue!55}{blue!15}</font><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000"> </font></span></div><div><font class="Apple-style-span" color="#000000">%%</font></div><div><font class="Apple-style-span" color="#000000">%\psSolid[</font></div><div><font class="Apple-style-span" color="#000000">%</font><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000"> </font></span><font class="Apple-style-span" color="#000000">object=fusion,</font></div><div><font class="Apple-style-span" color="#000000">%</font><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000"> </font></span><font class="Apple-style-span" color="#000000">action=draw**,</font></div><div><font class="Apple-style-span" color="#000000">%</font><span class="Apple-tab-span" style="white-space:pre"><font class="Apple-style-span" color="#000000"> </font></span><font class="Apple-style-span" color="#000000">base=cuthyperboloid cutcone hyperboloidtwosheet, </font></div><div><font class="Apple-style-span" color="#000000">%]</font></div><div><font class="Apple-style-span" color="#000000">%%</font></div><div><font class="Apple-style-span" color="#000000">%\composeSolid</font></div><div><font class="Apple-style-span" color="#000000">\end{pspicture}</font></div></blockquote></div><div><div><br></div></div><div>Here is the resulting picture:</div><div></div></body></html>