<div dir="ltr">Hmm, partially answering my own question, but it's obvious the output is
 not 2D, but I can't say I quite understand the product it is 
creating... .<br><br>Best,<br>Steve</div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sat, Dec 7, 2013 at 5:55 PM, Stephen Mather <span dir="ltr"><<a href="mailto:stephen@smathermather.com" target="_blank">stephen@smathermather.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>Hit send too soon...<br></div><div><div class="h5"><div><br>Hi All,<br><br></div>Digging SFCGAL... .  Quick question-- is 
ST_MinkowskiSum a 2D calculation of the Minkowski Sum when 
non-polyhedral surfaces are fed in?  For example, I tried this:<br><br>

<p style="margin:0px;text-indent:0px">WITH pointt AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_MakePoint(0,0,0) AS the_geom</p>
<p style="margin:0px;text-indent:0px">),</p>
<p style="margin:0px;text-indent:0px">buffered AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_Buffer(the_geom, 30, 20) AS the_geom FROM pointt</p>
<p style="margin:0px;text-indent:0px">),</p>
<p style="margin:0px;text-indent:0px">rotatedOnItsSideX AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_RotateX(the_geom, 0.25 * pi()) AS the_geom from buffered</p>
<p style="margin:0px;text-indent:0px">),</p>
<p style="margin:0px;text-indent:0px">minkowski_sum AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_MinkowskiSum(x.the_geom, b.the_geom) AS the_geom FROM</p>
<p style="margin:0px;text-indent:0px">          rotatedOnItsSideX x, buffered b</p>
<p style="margin:0px;text-indent:0px">)</p>
</div></div><p style="margin:0px;text-indent:0px">SELECT ST_AsText(the_geom) from minkowski_sum;</p><p style="margin:0px;text-indent:0px"><br></p><p style="margin:0px;text-indent:0px">I get:</p><p style="margin:0px;text-indent:0px">

<br></p><p style="margin:0px;text-indent:0px">MULTIPOLYGON(((-60 -7.45012945754965e-14,-59.9075200119938 -2.35377287183542,-59.8150400239877 -4.01814163088313,-59.538170229848 -6.35740271025471,-59.2613004357083 -8.01151008244411,-58.8017478297844 -10.3218370469144,-58.3421952238606 -11.9554849102494, (...)<br>

</p><p style="margin:0px;text-indent:0px"><br></p><p style="margin:0px;text-indent:0px">Thanks,</p><p style="margin:0px;text-indent:0px">Best,</p><p style="margin:0px;text-indent:0px">Steve<br></p><p style="margin:0px;text-indent:0px">

<br></p></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><br><div class="gmail_quote">On Sat, Dec 7, 2013 at 5:51 PM, Stephen Mather <span dir="ltr"><<a href="mailto:stephen@smathermather.com" target="_blank">stephen@smathermather.com</a>></span> wrote:<br>

<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>Hi All,<br><br></div>Digging SFCGAL... .  Quick question-- is ST_MinkowskiSum a 2D calculation of the Minkowski Sum when non-polyhedral surfaces are fed in?  For example, I tried this:<br>

<br>

<p style="margin:0px;text-indent:0px">WITH pointt AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_MakePoint(0,0,0) AS the_geom</p>
<p style="margin:0px;text-indent:0px">),</p>
<p style="margin:0px;text-indent:0px">buffered AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_Buffer(the_geom, 30, 20) AS the_geom FROM pointt</p>
<p style="margin:0px;text-indent:0px">),</p>
<p style="margin:0px;text-indent:0px">rotatedOnItsSideX AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_RotateX(the_geom, 0.25 * pi()) AS the_geom from buffered</p>
<p style="margin:0px;text-indent:0px">),</p>
<p style="margin:0px;text-indent:0px">minkowski_sum AS (</p>
<p style="margin:0px;text-indent:0px">  SELECT ST_MinkowskiSum(x.the_geom, b.the_geom) AS the_geom FROM</p>
<p style="margin:0px;text-indent:0px">          rotatedOnItsSideX x, buffered b</p>
<p style="margin:0px;text-indent:0px">)</p>
<p style="margin:0px;text-indent:0px">SELECT 1 as gid, ST_AsText(the_geom) from minkowski_sum;</p><p style="margin:0px;text-indent:0px"><br></p></div>
</blockquote></div><br></div>
</div></div></blockquote></div><br></div>