Okay, this thread is all yours, I'm signing off now. Bye.

 Kawecki. With all due respect.. are you claiming that the Poser 4 renderer is as good as Firefly in BagginsBill's hands? 

If so, then I'm off with Izi. That's just plain ridiculous.

Granted, NICE renders can be made with the basic Poser 4 renderer - but it can never ever be as good as a proper raytracing engind. Don't believe me? Then do ANYTHING with reflections. (not talking about faked stuff and postwork, but make me a real working mirror in Poser 4 and I'll be convinced.

Also.. please take a deep breath before hammering away. The typiong errors and such doesn't make it easier to understand.

(and yes I know you're not a native english speaker. Neither am I. And I recognize the errors I make when I'm agitated)

Quote - Granted, NICE renders can be made with the basic Poser 4 renderer - but it can never ever be as good as a proper raytracing engind.

Why not?, raythracing is not superior to other rendering methods. Raytracing is one redering method that thal allows you easily do some things, (at the expense of rendering time)  that are very difficult to do with other methods.

Quote - Don't believe me? Then do ANYTHING with reflections. (not talking about faked stuff and postwork, but make me a real working mirror in Poser 4 and I'll be convinced.

Real mirrors is one of the things, probably the only one, that can be done easily with raytracing and very difficult to do with other methods.
But...., on the other side it's impossible to render real clouds with raytracing!!!!....
It doesn't exist a superior rendering method, it are only methods each one with its advantages and disadvantages, where can be used and where can't be used and with personal preferrences.
Are oil paintings superior to acuarela, acrylic or DaVinci's uncoventional methods?????

My AO is raytraced. My shadows are raytraced and have realistic penumbra. My specular is the Blinn node. I took two minutes to render on a crap laptop.

I just looked at myself with the P4 renderer. My skin still looks good, but I don't have AO and now my eyes don't look as real as the rest of me. I have nostril glow. The depth-mapped shadow under my arm looks fake and my ear doesn't cast a proper shadow, nor does my nose. I took about the same time to render, unless I was to give up anti-aliasing, which would totally suck.

since when has poser 4 got all the bells and whistles of poser 7, ok poser7 may not be a great renderer but its better than Poser4,so i cant see why anyone would be moaning about posers rendering when they are not even on a current version, and why the hell are you moaning at us?
oh and BagginsBill also pointed out (in the last post) why anyone using P4 has crap renders....

It's amazing how small details are important when you notice them.

For example, if viewed alone, this P4 render seems very good (at least to a n00b like me) and it's already above my rendering skills.

Then you compare it with the Firefly render.... and you realize that actually is quite bad. The eyes are the first important difference, and the shadows are just another league.

Giorgio

I dont see how anyone can seriously think that the P4 renderer is anywhere near firefly in terms of rendering. Firefly may not be the best in its class, but it has a node based shader system, supports multiple threads (and rendering in a separate process), AO and IBL, support for HDRIs, as well as 64 bits if you have PPro. All of these are big improvements over P4.

P4 is better then firefly in what ? Less wear and tear on your CPU ??

Also this:

Quote - But...., on the other side it's impossible to render real clouds with raytracing!!!!....

Is totally wrong. Most apps that do volumetrics, use what is called raymarching (or volumetric ray casting), a modified version of raytracing. It's modified in that it not only calculates the start and end points of each 'ray' but also over the path the ray travels. This let's you take 3D procedurals and render them as solids of varying density, giving you a basic 'cloud.' That's how everything from vue to mentalray to lightwave does it.

Small clarification ... my P4 render above was using Firefly node-based materials. Otherwise, the skin would NOT have a proper Blinn specular or SSS or gamma correction, all of which were key to getting the skin to look right.

The point I was hoping to make is that even when you let the P4 renderer use Firefly's nodes, which takes away one advantage of Firefly, the handling of shadows is enough inferior that I would never dream of using the P4 renderer for anything other than a demonstration of why it is inferior.

These sorts of details are precisely why Poser is so much maligned in larger CG circles. Users who produce naive, even bad renders, featuring pointless nudity, proudly displaying them in their gallery - that's perceived as the essence of the Poser community. I hate that.

I'm fine with big boob pictures - just try to make them look real. It's not as though I'm keeping secrets. What you see above (lights, shaders) are available as freebies from me that you can use in a couple clicks. But you have to use Firefly and you have to use ray-tracing.

For a single object here is no difference between raytracing and any other rendering method if you use the same lights and the same mathematical model. It must be the same and can't be different, light behaves always in the same way.
The difference is when exist more than one objects and project its image over other objects or illuminate it, or the light path is bend.
In this case raytracing can provide more correct results where exist interaction between objects.
I am not speaking about shadows that can be handled in a correct way by various means, I am talking about one object illuminating or proyecting its image on other object.
When the number of objects is increased raytracing also fails to produce correct results because the number of bounces of a ray is limited to a small number due rendering time, in this case radiosity produce the correct result, but radiosity only handles illumination and not image proyection.
I am speaking in general and not of the particular implementations of firefly, Poser7 emulating Poser4 and Poser4, where each implementation has its own deficiencies (firefly is inferior to Vue)

Left to right:

Phong, Specular, Blinn, Glossy

Behind the props is a mirror. The direct view of the props shows front-lit specular and the reflections show the back-lit specular. The main light is out front, so the reflection simulaneously gives us the point of view from behind, i.e. back-lit, in a single render.

I excluded anisotropic because it is not a general-purpose effect. And no, it's not for very bright and tight speculars like on the eye. That is possible with any of the specular nodes, but not at their default values. The anisotropic node is for microscopically grooved surfaces like brushed aluminum. We'll talk about that some other time.

Notice three of the four agree on the position of the hot spot. The Phong node does not. The Phong node does not use the viewer position (camera) as part of its calculation. This places the hot spot pointing straight at the light, which is wrong.

The Specular (#2) node is the same as the Poser Surface built-in Specular. It is what most people use. It is pretty good, but not great. I use it when I'm lazy, because it's there. Notice that the back-lit specular does not spread out. It should, for a material like this that is not microscopically flat and glossy.

The Blinn (#3) is the right node to use for this type of surface. Notice that the front-lit specular is darker than the others, and the back-lit specular is brighter than the others. This is the Fresnel effect. None of the others do this on their own, although if you add enough nodes you can get them to do so. Notice also that the back-lit specular spreads out around the rim of the sphere. That's how human skin behaves, as do many other micro-bumpy surfaces.

The chief difference between the Glossy and the others is that the hot spot does not exhibit much of a gradient. The Glossy node is helpful when trying to compensate for the fact that most of our basic CG light sources behave like tiny points. The specular reflection of a tiny point is a tiny point. But a glossy surface, such as patent leather, shows in real life rather large specular reflections of light sources that are not points at all. Even a light bulb, which is pretty small, is not a point, and most real-world lighting involves fairly large circular or rectangular areas for light sources. Yet if we use a point source, we will not get a big hot spot. The Glossy node is a cheat that helps with that. It makes a large hot spot even though the physics of our model says it should be a tiny spot.

I sometimes use the Glossy node for this reason. However, as it does not exhibit the Fresnel effect, I would combine it with other nodes to make it brighter when producing a rim lighting effect.

This render is with gamma correction. Without GC, the specular effects are difficult to get right, and the reflections would be nearly invisible on most monitors.

Further, I have simply plugged in the nodes without a more sophisticated treatment that respects the conservation of energy. In most shaders, I do a bit more than simply plug in the specular node into Alternate_Specular. Let's talk about that for a bit.

There are many CG articles on the net that talk about the specular reflection and diffuse reflection. Most get the description of the effect correctly, but almost all are absolutely 100% wrong when explaining how they happen, and why they appear to be different.

Here is one that does not get it wrong, and even points out that the others do get it wrong.

The Dimensions of Color by David Briggs

I suggest that you read that article about 11 times, or perhaps more, until you can repeat everything it says with confidence and understanding.

So a specular reflection is this: Light interacts with the air-surface boundary, and bounces off immediately in a new direction which is based on the the angle of incidence. The new direction can be smeared out a bit if the surface is microscopically bumpy. This is what mirrors do almost 100%.

Diffuse reflection is this: If the light ray/photon/wave does not bounce immediately, then it enters the surface and gets aborbed by the material. It can then do several things - it can become heat (jiggle the atom more) or it can elevate an electron to a higher energy level, or it can travel around inside and do more complex things. When an elevated electron comes back to normal (and it eventually does) it will emit a new photon, with a new color, and in a new random direction. Any direction has equal probability as any other.

Notice my description of the Diffuse reflection began with a qualification; "if the light ... does not bounce immediately". Effectively what that means is that you should model the specular effect as something that can happen first, with a certain probability distribution. When specular reflection is highly likely, diffuse reflection is highly unlikely. When specular reflection is less likely, diffuse reflection is more likely.

So a super accurate handling of the specular/diffuse effect would involve combining them into one calculation where one depends on the other. Poser nodes don't quite let us do this with that kind of precision. As a cheat, I generally subtract the output of a Blinn node from the Diffuse_Value of my diffuse node in some way. This is not physically accurate, but it is more correct than doing no coupling at all.

Observe the locations of the hot spots. The Phong node is completely inappropriate. Just don't use it.

Notice that because the front side and back side (reflection) form similar angles with the light and viewer, the front-lit and back-lit distinction is nearly gone. This is side-lit.

Quote - These four are all Blinn at various settings. The Blinn node can accurately portray a very wide range of micro-bumpiness, from nearly smooth to craggy. (Microscopically craggy, of course. You could not see the little mountains with the naked eye.)

what if we wants a wide backlight specular and small specular infront.
then we combine one blinn and a normal specualr. right?

Leaving aside that there is no basis in reality for such a case ...

If you combine a rough Blinn and a sharp Specular, the Blinn will still produce the rough round highlight in front and a rough crescent highligh in back, and the Specular will produce a sharp round highlight in front and back. So that would be a no. Just look at my first set and imagine adding the #2 and #3 together.

What you're talking about is modulating the sharpness based on viewing angle. So you'd use an Edge_Blend (and maybe more nodes) to create a modulated setting for the eccentricity, which would be low when facing the viewer and high when facing away.

#1 is a rough Blinn
#2 is a sharp Specular
#3 is those two added together (not a bad start for a shader for metallic car paint - this really happens!)
#4 is a modulated Blinn so its sharp in front and rough in back

wooow.

Quote - Leaving aside that there is no basis in reality for such a case ...
.

i was thinking for wet skin.
so if we have wet skin and have a backlight it will not be wide? 

No it won't. The specular effect occurs at the air-surface boundary. If the skin is completely 100% covered by water, then the skin does not meet the air at all.

Of course, that never really happens. There are droplets, and dry areas. So what you really want to do is have a droplet mask. You drive the Blinn parameters with that mask. Where there is water, use the sharp settings. Where there is no water, use the rough settings.

Observe how there are dry areas and wet areas. The dry areas have a rough weak specular. The wet areas have a strong sharp specular. These are from the same Blinn node. The variation is produced by having a droplet bump map. Instead of an actual map, I used a Fractal_Sum node. Doesn't matter how you make the map, image or procedure, the point is the Blinn handles both materials simulatenously.

Observe how the wet areas appear to be darker and more saturated. This is entirely due to the absence of a soft specular from the "skin", because the "skin" is covered by water.

Oh the other thing this is missing is real reflection. The water would show reflections of the environment. If we added that, it would look even more real when there is a brightly lit environment.

Quote - No it won't. The specular effect occurs at the air-surface boundary. If the skin is completely 100% covered by water, then the skin does not meet the air at all.

Of course, that never really happens. There are droplets, and dry areas. So what you really want to do is have a droplet mask. You drive the Blinn parameters with that mask. Where there is water, use the sharp settings. Where there is no water, use the rough settings.

dumb me. for wet skin you are right.
but if it is more like oil. ''oily'' ? 

:) 

Quote - I did a simple scene and both Poser4 and firefly failed giving almost the same render.
The scene is a simple plane (big box) illuminated from behind with a directional light at 45 degrees.
The green lines are cylinders indicating the incident and reflected ray from the plane.
The reflected ray should have illuminated the small box making it visible, but it didn't!
I agrre with the result of Poser4, Poser4 cannot do this, but raytracing (firefly) should have done!!
The bounce number was set to 4, enough for the only two bounces that exist in the scene.

you mean that the light should bounce from the reflected sourface?

of course poser doesnt support this. he he :)

exactly. thats often called Radiosity and is NOT a feature of the Firefly render engine.

-10 points to Kawecki for not reading the manual.

Is not radiosity, radiosity works in another way and radiosity doesn't deal with specular light.
It is a simple raytracing, but if you put the light in front instead of comming from behind it works in Poser.
Is raytracing sensitive to the light position???
It looks as Poser doesn't like back lights.

I have 3 cars.

The BMW can go 200 miles per hour and is pretty safe, but is unable to climb rocks, won't move in snow at all, and uses a crapload of gas. Plus it cost much more than most people make in a year.

The Volvo can do 130 MPH and eat snow like crackers and is extremely safe but it still sucks quite a bit of gas  and won't really climb big rocks and cost a year's pay for most people.

The Jeep is good on gas and can climb rocks, but only goes about 95 MPH before it starts to wheeze and if a truck hit me in it, I'd be dead, but it only cost $20K.

(Please do not point out to me that the speed limit where I live is 65 MPH. I like to accelerate from 0 to 30 in 1.5 seconds - merging traffic and all that.)

So I'm a bit dissatisfied with the Jeep.  I'm thinking of complaining to Jeep (as well as other Jeep owners on the Jeep forum) that it isn't the rock-climbing-snow-leaping-Porsche-eating family sedan I wanted it to be. I mean, come on, they all have an engine, four wheels, a body, seats, and so on. Why don't I get all the best features in one car at the cheapest price? I don't get it.

Oh, is that off-topic? Sorry. I thought that's what we do here.

I have a mountain bike myself....

I wish I had a mountain bike. I bought a "hybrid" bike about ten years ago. Unlike a mountain bike, it always gets stuck in sand and rocks. And unlike a road bike, it doesn't roll real super smooth on pavement, so i always have to pedal a bit harder than friends on road bikes. Really, it doesn't do anything well at all, except it was cheap.

I'm going to return it.

I recently got a really slick digital SLR camera - Nikon D90. Prior to that I was using this Canon Powershot - nice little pocket camera - if you're a noob. I've had the pocket camera for 4 years and it always made great pictures. But now that I know the power of the Digital SLR and lenses that cost more than my annual life insurance premium, I'm kind of unhappy with the Canon.

I'm going to return it.

Still trying to figure out how to fit the 70-300 VR lens in my pocket. It's so freaking heavy, too. Why is that? Are they idiots at Nikon, making a fricking lens weigh 3 pounds?

A goat can climb rocks, is cheap, consume no oil at all and is ecologically correct, something very good for the global warming paranoia.
Speaking about raytracers, PovRay is for free.......

A goat can climb rocks, is cheap, consume no oil at all and is ecologically correct, something very good for the global warming paranoia.

If ya got a goat there's no need for a lawnmower either.

Interesting points you've brought up,  Kawecki.  After all math never lies as long as we follow the order of operations.

If you want Porsche performance

             wait for it ...

get Carrara!

Quote - Still trying to figure out how to fit the 70-300 VR lens in my pocket. It's so freaking heavy, too. Why is that? Are they idiots at Nikon, making a fricking lens weigh 3 pounds?

Think that's bad? Try this beast !
www.warehouseexpress.com/product/default.aspx

Quote - Think that's bad? Try this beast !
www.warehouseexpress.com/product/default.aspx

I want to go to there.

One thing you can say about Nikon, their glass is very well put together and is a bit cheaper than the Canon L series

I am really enjoying this thread, and Thankyou Bill for explaining the nodes it has made it very clear to me,you are a Poser GOD...