As you can see, in losing the artifacts, you also lose the wonderful refraction and the biggest difference in the matroom to me, seems to be Transparency 70% versus 93%. Of course, a transparent material isn't going to do any damage to anything, right? 93% is almost there.....

Just a few days ago, it was more or less discovered that the artifacts were caused by backfacing polys in the glass-material. Try deleting the backfacing part of the glass with the Grouping tool. However it seems it is also related to the proximity of other things to the glass, as in how close they are to the cheeks. The lexan-material looks cool btw, eventhough the refraction is missing.

I read that thread and did not get that it was solved. I'll read again... Thanks, ernvoka

A few things: * Always set the background color of the reflection and refraction nodes to the background color of your scene, or if you're using an background image/movie, use that one in conjunction with a sphere-map node. * When using refraction, set the transparency of the Poser Surface to 0 (as described in the manual and the room help - the manual is better than its reputation). Yes, that may sound odd at first, but that's the way it is in all things RenderMan. * As soon as you did that, you can reduce the reflaction_value and reflection_value to values < 1.0. No real material is 100% reflective or refractive, and this will cause problems with multiple bounces. * Multiple bounces - that's one problem you will have as soon as your glasses are thicker than one polygon. A refraction ray will bounce back and forth in the glass, until it hits the max number of ray trace bounces and is being rendered black. The higher your reflection_value is, the more this black pixel will be visible in your final render. Try to have low reflection_values, or make it single-sided (you can fake reflections with an environment map, which is more predictable and renders much faster). hope this helps.

Attached Link: http://www.renderosity.com/messages.ez?ForumID=12356&Form.ShowMessage=1863284

What are the material room settings for this last one? As Stewer says, the refraction value should always be less than one. Ideally, the reflection and refraction values should add to less than one. That's the first thing that strikes me about the material settings in your first post. That crystal mat has a refraction value of 1.9

Hey Ajax... Hoping you might see this. Refract settings are identical to the 1st. 1.9/1.87 and is there only to force an effect. Once I change a thing that effect will dissappear. I'm out the door just now but will reset the nodes as advised. I'll render any settings you leave here. Back in 4hours, R

I've tested your last setup with a single sided square and a very thin box prop. Changing the render settings had no effect. Playing with the material settings had no effect (even when "reflection + refraction = 1"). Changing any of the colors in the materials had no effect. There was nodifference as long as the single sided square was in the SAME distance to the face as the front side of the box prop. This distance between the front of the glass and the surface is the only crucial parameter. So far - the only way to prevent those ugly artefacts is to increase the distance between the glasses and the face. Make the lenses smaller so you can have a greater distance to the side of the nose. This seems to be a real flaw in the firefly renderer. Willy

Thanks Willy. You saved me a lot of time and another thread listed above came to the same conclusion. But you don't know Ajax! I can taste a real cure. Wish I had more time. Triangulation of light, camera and refracted object is my next hunch. Hopefully some more realistic settings will work too.

Hiya Richardson, I hate to dissappoint but I'm as stumped by this as anybody. I've seen a few threads about this and the reason I haven't posted before is that I haven't been able think of anything useful to say. This time when I saw that refraction value of 1.9 I thought that had to be it, but I guess not. I think Stewer is the most likely person to come up with an answer for this one. He knows the render engine and the way the material nodes work better than anyone else I know. It might help if I could duplicate the effect on my own machine, but I haven't encountered it at all yet. Do you think you'd be able to set up a simple pzz file (say a sphere and a plane) that has this effect and then send it to me so I can try it out?

Did you try and adjust the Shadow Min Bias on the Ray Traced light? It might not eliminate the problem but it may make it less visible. Also, the quality settings on reflect/refract have a lot to do with the "grainyness" of the result, and so does pixel samples and Minimum shading rate in the Render Options. It could be some combination of all of these working together to produce the final result.

taking a breather on this one -- I've been working on it pretty heavily for three days now. If it's a bug, it's only partially duplicated through variations. I'm leaning towards a computational limitation (call it a bug if ya want, though, my being a stickler don't mean yu gotta be). Meaning: it's out of the range of the rendering engine. Might not be, but that's what I'm leaning towards. It's ray based, proximity involved, shadow independent, and object independent. Facing of polys does affect it, but only slightly. It occurs mostly, though not always, when you have a situation of multiple shadowed areas in a rayed scene involving transparency, reflection, and refraction. To effectively track it down exactly, your entire set up: lights, materials, and render settings. I had my blinders on as well - Ajax is right. Based on the method by which this stuff works, the sum of refraction and reflection needs to equal 1 in the Poser_Surface.

Now that you posted that pic, ynsaen... Do you (or anyone else) know why those raytraced shadows tend to dissolve into ugly little spots/speckles? As in the nostrils and teeth/eyes of this one? It's driving me nuts. I know I could overcome it with shadowmaps instead of raytraced shadows, but I LIKE raytraced shadows!

The little dissolving thing is due to the shadow bias of the lights. On the properties tab of each light is a dial that says shadow min Bias. adjust it. The lightset above is the poser default lights all changed to raytrace. Let me call that up again and adjust then re render to show...

Yeah I've tried that 2 light idea too, with good results, and I have tried to fiddle with the shadow bias before, but apparently not enough. Thanks for telling me WHERE to fiddle L

Vnsaen, You have to drop your transparency to get refraction. You have an almost invisible lens. (2nd post). Dropping bias on a Ray T clears up the shadows and dropping the Ray T shadow to .100 will render a Ray T shadow (normally harsh), invisible so you can use a depthmapped (controled) shadow in its place. All True But where are the myopic lens? Gotta go to work. Ajax, I will try. Not with a Stefy skin, though! LOL

.

broke the rule in the second one -- went to a 1.15 total Your refraction number for the lens is wrong. You are using a number for the base material without shape distortion. You need to adjust the actual refraction number of the material to reflect the warping produced by the lens shape (perhaps the cosine of the prescription?) instead of altering the the Poser_surface setting for the reflection.

I know my refract settings are wrong. Doing anything to the settings just kills the effect. The refract settings have nothing to do with the artifacts. (on mine, i'm almost sure) And reflect settings are a separate issue. Mine are off. I just need a few more tweaks and I'll have it. Nice transitional lens, vnsaen

YES!

Attached Link: The Solution is here

Wow... So maybe the new owners of Poser (or CL, or whoever, I'm out of touch lately) should get together with the people who originally MADE Firefly and get a patch out to us, eh?

Well, I started this thread so I'll say that I think this baby is solved. I never would have gotten it either. Just too far out of the box for this soul. Setting up my scene all scaled up would be a waste of time to me, too because the logic given in the solution thread explains why so many have stumbled on this. ronstuff, I read back through this thread and others and can say with certainty that you've got style....(but, soccer?):) Thanks to all and to all...decent renders!

Actually its pretty easy to scale a whole scene. Just open the heirarchy editor and anything that is not already parented or conformed to Figure 1 (or any of the main scele elements), just parent to the same object. Then scale that one object with everything parented to it and the whole scene is done at one time.

Great discovery. Now who's gonna write a pythonscript that scales everything up to a 1000%? Like the Z-flatten script I guess... Only I know nothing about python.

... great looking glasses! ... anxiously awaiting shadows - though I know they will still be sharp edged, but at least they won't be serrated :-)

Nice to see this one laid to rest. Great work, Ronstuff!