I think I understand how to get reasonable reflections in general. Use a reflection ray-trace node, set the background to black, plug it into the reflection input in Poser surface. Usually keep the reflection color white, but can play around with textures for special purposes. (For example, if you have a tinted mirror.) The sum of the reflection strength and the diffuse strength should be one or less.

I have a couple of questions:

1. How can I make the reflection less "clear" or mirror-like? Not necessarily weaker, but more wavy and distorted, as if the mirrored surface had imperfections or was not smoothly curved. I can get some of that with the quality input in the reflection node, but is there another way.

2. It appears that if you plug any other sort of node into the reflection input, you end up with a self-illuminating material. (This is particularly noticable when you use gamma correction.) Is there any way to get around this other than using a reflection node? I kind of like the look (in an artistic, as opposed to photoreal, render) you get with the old technique of using a reflection map as input to a sphere map plugged into the reflection input, but it just doesn't look right when using gamma correction (or even reasonably low lights), and it isn't "shiny" enough if you dial down the reflection strength.

For number 1, disturb the surface with bump and you'll get disturbed reflections as you seem to want.  I'm sure there are other ways to do it but imo that's the most straightforward.

For number 2, I think Bagginsbill showed a long while back that most of those inputs in the PoserSurface root nodes do essentially the same thing, bypass the lighting model and just output diffuse color, so whatever goes in will come right back out with no regard to lighting except for specific nodes like Reflect that are designed to handle lighting themselves.

With a few exceptions that take considerable time to understand, the inputs Reflection_Color, Refraction_Color, Alternate_Specular, Alternate_Diffuse, and Ambient_Color all do the same thing. They add to the color of the rendered pixel. Exceptions to this simple rule involve transparency and specular effects, as well as the implications of Reflect_Lite_Mult and Reflect_Kd_Mult.

The Poser Surface is like a receiver/amplifier/mixer. The tuner part of the receiver is analogous to the built-in diffuse and specular effects - controlled by the first five parameters of the surface.

The other XYZ_Color inputs are like auxiliiary inputs on a amplifier/mixer. Whatever is plugged in goes into a little pre-amp (the color chip and the XYZ_Value if there is one) and then that simply gets added (arithmatically "plus") to the internally generated color produced by the built-in diffuse and specular.

So - when you plug something into any of these channels, whatever that is gets added to the output. (Suitably pre-amped by the color chip value and the XYZ_Value - both of these are simply multipliers of the plugged in value.) And with some exceptions as noted above.

The pre-amps do nothing when the color chips are set to white and the values are set to 1. White is 1.

Assuming your pre-amps are 1 or white in all cases, and no transparency is involved, and Reflect_Lite_Mult and Reflect_Kd_Mult are disabled, then all of the aux inputs are identical.

Jamming a fixed set of colors in, such as plugging an Image_Map into one of these aux inputs, always does the same thing. It simply adds the colors of that node into the mix. Same as ambient. Self-lit. Doesn't matter which aux input you use - their job is to take the input color at face value and just send it on.

Now the job of some nodes, such as Glossy or Clay, is to calculate the effect of lighting. You include these effects by plugging such nodes into Alternate_Specular or Alternate_Diffuse. Those channels do nothing to modify the colors they are given (other than the pre-amp part) and so what those nodes produce goes into the mix.

A Reflect node looks around (casting additional rays) at other objects in the scene in various directions and adds those colors into the mix. So does a Gather node. So does a Refract node. Which aux input you use these in doesn't change anything.

So it's not a good idea to simply shove a reflection map into the Reflection_Color channel. The channel doesn't do the actual reflecting. It simply takes the input colors and adds them to the mix. It glows.

So now you know why you get a self-illuminating material when you shove colors into an aux channel with no calculation of light involved.

As to a softer reflection, more blurry - increase the Reflect node Softness parameter. WARNING: Long render times result, because now it must send multiple (perhaps hundreds) of additional rays out for every pixel. When doing blurry reflections, you must increase the Quality, which will put you into hundreds of extra rays for sure. If you have lots of bounces, two such surfaces near each other will explode the number of rays needed into the billions. (A point on object A throws out 100 rays. 60 of these hit another soft reflector, B, which also sends out 100 rays for each of the original rays. That's 10,000. A third bounce from B hits A and A sends out another 100 for each of those 10,000. Now you're at 1 million rays with only 3 bounces. Death to you.)

Perhaps you mean just more irregular. This is accomplished by putting some sort of bump into the surface. Various noise nodes, such as Noise, Granite, Clouds, etc. can be used for this, or you can use an image.

Also, perhaps you're becoming aware of the need for the Fresnel effect. This effect is that light reflects more strongly when it hits a surface at a shallow angle. Edges of things look shinier than the parts that face you.

A cheap way to do a Fresnel effect is to modulate the reflection via an Edge_Blend node. However, the math is not correct and this is only slightly more real than not doing it at all. Better is to use Schlick's approximation. Best is to use the real Fresnel equations.

Search this forum and the Node Cult at RDNA for posts by me using any or all of the following words.

Fresnel

Glass

Water

Plastic

Metal

Shlick

PS - Cross posted with PJ. Hi PJ.

Hi :)

I actually am just kicking the tires with GC and it seems to me that reflections come out too bright with GC on, I need to fool around with that some more.

I was looking for both softer and more irregular. I'll try some of these ideas out when I get a chance.

thanks

Quote - Hi :)

I actually am just kicking the tires with GC and it seems to me that reflections come out too bright with GC on, I need to fool around with that some more.

Typical reflection values in real life are .01 to .03, or in percentages, 1% to 3%. With GC those are the kinds of numbers you need.

It's not that GC makes them too bright. It's that monitor gamma makes them too dark and everybody is used to boosting the reflection factor to unrealistic values. This is one of the many typical gamma "compensations" people use without realizing that's why they're doing it.

Some examples from the real world:

Realistic reflection value when viewing a surface pointing right at you:

Polished Wood: 0.66% (.0066)

Water: 2% (.02)

Thick Glass: 4.5% (.045)

Thin Glass: 7% (.07) (With thin glass you get thousands of inter-reflections between the front and back surface. They add up to 7%.)

Diamond: 17% (.17)

Chrome: 65% (.65)

Telescope mirror (silvered): 90% (.9)

Yeah I haven't used more than 90% reflection in a long time, I need to fool around with it a bit before I really decide whether it's just my perception or what.

Nah I guess it was just that particular combination of light and angle, I can't reproduce it.

Good explanation BB, just a little question, in your last glossy shader ( for example) we have many input :

Gamma ( auto )

Color

Diffuse

IOR

Reflectivity

Blurr

If i want a wood shader, where to put the 0.66 % values ?

That shader uses the full Fresnel equation and computes the .0066 on its own.

Set IOR=1.33 (I'm truly just guessing that the IOR of the finish on the wood is similar to water - not really sure about that)

Set Reflectivity = .33 (i.e. about 1/3rd as reflective as water)

This will result in a minimum reflectivity of about .66%. The maximum will be 33% (at the edges).

I can't find any specification of the IOR of varnish or furniture polish. I've seen claims on the web that say IOR for shiny wood is 3 to 6 but that's impossible. Among non-metals, also known as dialectrics, an IOR higher than 3 would only come from exotic materials and coatings. Within the realm of dialectrics one might encounter in everyday life, diamond is the highest at 2.419. The somewhat exotic material titanium dioxide (used in sunblock and painter's pigments) is very white and bright, with an IOR of 2.496, but it is usually a powder and does not produce a "shine". It's just really white as all the microscopic surface variations make it pretty much all diffuse reflection.

Ok thx ;)