>Christopher James Huff wrote:
>>No, the second glass refraction is ignored. POV maintains a list with
>>the objects it is currently "inside", which lets it figure out when
>>refraction should be done.
>>
>I know that's probably what's intended, but I'm just looking at the code.

I ran a test to confirm my suspicion.  Rays were refracted twice at an ior
of 1.57:1.33, once on entering the water, and once on leaving the glass
(into the water).  I did the test with POV-Ray 3.5 for Windows (Version
3.5.icl.win32)

If it really is supposed to work the way you described, where it only
refracts when leaving a surface if it's the last surface entered, then we
should make the following code change:

      /* The ray is leaving the current object. */
      Ray_Exit(&NRay, nr);
            if (NRay.Index == -1)
      {
        /* The ray is leaving into the atmosphere. */
           .......
      }
      else if (NRay.Index+1 == nr)   <------ this line was changed.
      {

I could be off by one.  But as I read it, NRay.Index should equal nr if the
ray is leaving the last object entered.  After the call to Ray_Exit,
NRay.Index will be reduced by one: hence the "+1" in the if statement.

I apologize if this post appears twice.  I posted a similar response last
night, and it hasn't shown up yet nearly a day later.

By the way, do the developer's read messages in here?  Who would I talk to
about making this code change, if it is the way it should be handled (the
documentation doesn't really describe the way it's supposed to work in
tricky scenarios like this)?

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