??????? So let me get this straight. You actually quoted Richardson's question from post 5 and part of my answer to it, so you know he was specifically asking about an unspecified substance with a high degree of both reflection and refraction but you feel that a "pragmatic", "pratical image production" answer to his question would have been something along the lines of "Just use a mirror - I know you asked about something with a 0.4 refraction value, but in the the vast majority of cases that's not relevant except in close up images - after all this thread is about mirrors."? I'll stand by my original answer to his question, thanks. I think that's about as pragmatic an answer to the question he asked as you could have. It was a much more timely answer too, given that it was posted nine months ago. "In the vast majority of cases, refraction doesn't come into it (in image production terms). After all, how often do you create an image that sees both sides of a piece of glass?" Apparently I should have left out the glass window example since it seems to be confusing the issue. Now it's there, I'll try to explain it a bit better. While you may not be seeing yourself through the glass, you can bet you are seeing some things that are on the other side of it. Some of the light from those things gets reflected back toward them. This reduces the amount of light that you see from them, dimming their image. If you fail to take account of this, you'll wind up with a window that has more light coming off it than the amount that was in the scene in the first place. In "practical image making" terms that means your object (whether it's a bathtub full of water, a block of glass or an aquarium) will look wrong, appearing to be washed out and/or glowing. So how do you take account of it? In strict physics terms, the proportion of light that gets reflected/refracted depends on the angle at which the light strikes the surface of the object. It's pretty hard to do that accurately in Poser. The pragmatic approach is to make sure that the sum of the reflective and refractive values of your material add to 1 (assuming you want a completely transparent material with no diffuse component). The underlying assumption (i.e. fudge factor) behind this approach is that the proportion of light coming off objects on the other side of the window that manages to get through the window and come toward you is the same as the proportion of light coming from you that manages not to be reflected and to go out through the window. So it's not a question of how often you see both sides of a piece of glass, it's a question of how you get a believable amount of light coming from a transparent object in your scene. Given how many e-mails I get asking about this, I wouldn't say it was a particularly esoteric topic. It seems there are a lot of people out there interested in rendering nekkid vickies in a pool or a bathtub or looking into an aquarium and who want both the reflection and the refraction.

View Ajax's Gallery - View Ajax's Freestuff - View Ajax's Store - Send Ajax a message