hi BB

back from sailing I see. I like the reflection example, must have missed it in 2006 :)

My main point is the following (and we agree, as far as I'm aware):

especially when it comes to reflection, refraction and shadowing, the methods, options, settings and results from FireFly cannot be fully understood in terms of rays and tracing alone. One cannot do with simple schemes and base logic only, one has to show and tell using FF renders - as you're doing above. FF might be different.

FF results may differ from expectations, differ from those produced by recent resource intensive routines using "classical/pure" raytracing. Plus some FF methods / material+light settings are harder to comprehend because they're around for compensating the shortcomings of FF - and then one needs to accept and understand their existence first.

According to this thread and many others, a lot of Poser users don't find it easy to do so.

Whether or not FireFly is using "pure" raytracing for handling some situations is something I cannot determine from the outside, but

• It hardly did when it was the NPR:Reyes 3DSMax plugin and brought into Poser 5 (2000/2002), and I've not seen major changes since then (with respect to this area)
• I can dream up an algorithm - efficient or not - that produces the same pro's and con's in this area as FF does, without using any pure raytracing technique
• I've never seen any explicit proof that FF does raytrace indeed instead of doing it differently

but nevertheless, I keep on stating that FF "is not raytracing" to make people aware that its workings and result do deviate from expectations and pure raytracing routines. It does come pretty close though, and one could question the relevance of the deviations, but I happen to know some Poser users that make a sport out of making those as small as possible.

FF issues in overview:

• handling thin glass / dual reflections
• handling varying thickness of colored glass
• handling colored shadows/projections from wineglasses and stained glass windows
• handling direct light and objects + indirect lighting completely separate
• handling fresnel for thin glass/metals and for thick glass w/direct light - we've got a fresnel node now for glass reflections only, and why do we need a separate node in the first place? It's to compensate a fundamental shortcoming IMO.
• handling reflection / refraction / shadow from distorted surfaces (displacement, smoothing, ...) 
• shiploads of hard to comprehend / to explain material nodes and parameters that I've never seen in pure raytracers (because they don't need them)
• and so on

So let's face it. This is our Poser, this is our Firefly, it's pretty good, and unless someone starts adding something very fundamental, these issues won't go away. For by far most people, those "issues" won't bother at all. Some might seek improvements elsewhere, and interface with Vue, Max, LuxRender or anything. Which - according to the Law of Conservation of Misery - will bring new issues by itself.

Let's render. And learn.

- - - - - 

Usually I'm wrong. But to be effective and efficient, I don't need to be correct or accurate.

visit www.aRtBeeWeb.nl (works) or Missing Manuals (tutorials & reviews) - both need an update though