🚀 go-pugleaf

While there's a little attention focused on prman and qrman I'll insert
my favorite question into the discussion:

How on earth do you create shadows with prman???  The basic idea is
simple, create a Z-buffer image, use RiMakeShadow() to convert it to a
shadow map, and use the shadow map in a light source shader with a
shadow input (shadowspot, etc...).  Everything breaks down at the
first step though, since it looks like NeXT left out the ability to
write Z-buffer images!  Thus - no shadows, no photorealism, no
nothing.  I'm very frustrated about this...

So has anybody worked out the technique?  I'm completely stumped after
wasting hours and days trying to get it going.  NeXT's
vapor-documentation doesn't help of course...

Shane