Here's my simple test. This is a ball prop with a displacement map (white dot on gray) and a texture map (slightly bigger red dot on white). Displacement value: 2.0. The ball is in front of a single sided square prop. The square prop has a Reflect node, Quality: 0.2 and Softness 0.0. Firefly render, production quality, displacement ON, raytracing ON, casts shadows OFF, smooth polygons ON.

In the reflection, Firefly appears to ignore smooth polygons. Firefly also appears to try to do something in the displaced region, but not the right thing. The speckling near where the ball meets the square goes away by scaling everything up, but not these other symptoms.

Ideas?

It certainly doesn't reflect displacement. Never experienced a problem with smooth polys, though that may be more to do with the fact that the reflections I've had were of fairly high poly objects.

I've seen the "won't reflect displacement" error b4. Have you tried scaling the scene by 10 or 100? May help.

"Have you tried scaling the scene by 10 or 100? May help." "The speckling near where the ball meets the square goes away by scaling everything up, but not these other symptoms." I'll take a guess at yes, he has.

The answer on both counts is no. Firefly uses the Reyes renderer subpixel polygon subdivision method which has a lot of advantages over mesh subdivision techniques (such as detail) but doesn't (and isn't intended to) work in raytracing. There was a long investigation thread in the now defunct beta forum last year. Prior to SR3 Poser attempted to emulate displacement by moving mesh vertices, but often gave wildly unpredictable results and CL replaced it with bump mapped reflections in that SR. It would be possible to use volumentric calculations to give displacement in raytracing, but the raytracer would need to treat every polygon in the scene as a volume and that would have a major impact on the render times of Poser scenes. Bill

On second thoughts, and looking at the picture its possible that CL haven't replaced the vertex displacement scheme with bump mapping and what you are seeing is in fact the "wildly unpredictable results" that I mentioned. Which version of Poser are you using, BTW? Bill

face_off, yes I tried scaling up. Bill, I'm using windows P5 SR 4.1 (5.0.4.325). Thanks for your explanation. This sounds, sadly, like a limitation. Jeff

Hi Jeff

My bad for assuming that they had actually changed the functionality.

The picture above (SR4.1 again) is a reproduction of some of the ones that I put in the beta forum thread.

The ball on the left is a standard Poser ball with a noise node attached to the displacement channel and Displaceemnt value 5. Rendered using the scanline Reyes algorithms.

On the left is that same prop reflected in a mirror using Firefly's raytracer. The effect is due to the fact the mesh vertices are being displaced in an attampt to emulate the scanline displacement.

Unfortunately as the mesh density is much lower than the detail in the noise pattern, the effect is the random clumpiness.

Bear in mind that the displacement algorithms were really developed by Pixar to enhance surface texturing, not to create modelling detail. It is a bonus that in scanline rendering displacement can be used to enhance geometry, but (not to look a gift horse in the mouth) this unexpected bonus only goes so far.

Bill

Message edited on: 02/01/2005 16:54

Attached Link: http://user.txcyber.com/~sgalls/index.htm

You could use PoseRay to subdivide and displace the model there and reimport it into Poser. http://user.txcyber.com/~sgalls/index.htm check out PoseRay's manual for more info.

• takes a few notes *

More things to watch out for with raytraced reflections, I suppose.

For Poser 6, I do hope CL has fixed the reflection culling bug that occurs when shadow maps are enabled.