On 04/05/2010 4:19 PM, David Winsemius wrote:
On May 4, 2010, at 4:09 PM, Michael Friendly wrote:
For use with rgl, I'm looking for a function to draw a plane in an
rgl scene that would function
sort of like abline(a, b) does in base graphics, where abline(0, 1)
draws a line of unit slope through
the origin. Analogously, I'd like to have a plane3d function, so
that plane3d(0, 1, 1) draws a
plane through the origin with unit slopes in x & y and plane3d(3, 0,
0) draws a horizontal plane
at z=3.
I see that scatterplot3d in the scatterplot3d package returns a
plane3d() *function* for a given
plot. I could probably try to adapt this, but before I do, I wonder
if something like this for
rgl exists that I haven't found.
?quads3d
It's harder than that, because a plane intersecting with the bounding
box of the data doesn't necessarily produce a quadrilateral: some are
other polygons (e.g. an
intersection near a corner can be a triangle). Plus, you want to still
see a plane if you add new data and change the bounding box. So this is
something that really needs to be done at the C++ level, and though I've
wanted one every now and then, I've never got around to adding it.
Maybe soon.
Duncan Murdoch
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