I saw this on the Daz site and wondered if there was a way to get the same Effects in Poser 8 with nodes or something?  

[http://www.daz3d.com/i/shop/itemdetails/?item=10354

](http://www.daz3d.com/i/shop/itemdetails/?item=10354)

I guess you could get something similar by playing with nodes in the atmosphere material and Poser's depth of field.  DOF in Poser is extremely slow however.   I´m sure bagginsbill and other material experts will be able to help you more. 

that looks mainly like volumetric lighting which you can do for real , or fake using some props and materials.

 Check out Adam Thwaites' "Room of Light" ... It'll probably get you there. And if you're not sure, ask Adam. He's a great guy and very good at creating what is useful.

http://market.renderosity.com/mod/bcs/index.php?ViewProduct=56531&Start=31&vendor=421351

 Thanks for the answers.  :)

The Room of Light looks interesting, but I notice it's Poser 6 & 7 and I'm running 8.  I know there were some changes done to the way lighting works in 8.  Maybe I'll contact the merchant to see if this will work in 8 too.  It seems to do nearly the same thing.

From what I've seen, I know some work in layers and postwork some of the Effects in, too.  One of my new favorites has a great green swirly atmosphere that's postwork. 

DA

You can get fast z-depth "fog" effects in Poser using the Depth Cue feature in the Atmosphere node. It's much quicker than Volume.

Edit: there is also a Python script that will output a z-depth mask. I can't recall who wrote it.

Doing this fog effect is easy, as IsaoShi showed.

The only thing you have to do besides turn it on is pick a fog color, and a start and end distance for the fog. These are DepthCue_StartDist and DepthCue_EndDist. From the camera to the DepthCue_StartDist, no fogging will happen. From there it will increase until it reaches 100% at the DepthCue_EndDist.

Here is a simple village scene I'm starting with, before applying the Atmosphere.

My Poser display units are in inches, so I'm starting the fog at 100 inches and ending it at 1000 inches.

The sky is completely fogged because it is 9000 inches away.

By the way, while this is usable, it isn't physically correct for fog. SM should update the Atmosphere fogginess relationship to distance, just as they updated the light falloff.

The equation being used to calculate the "fogginess" factor is Clamp((x - start) / (end - start)), which is a linear increase, where x is the distance from the camera.

The correct equation is x / (k + x), where k is a user-controlled parameter that defines the distance at which the fogginess is exactly 50%.

 That's Awesome.. I'll play with it.  Can you make it thicker at the top or bottom?  

DA

I'm fairly sure this can be done (to an extent) by using the Y component of a P-node to control the DepthCue distance settings. Unfortunately I don't have time to set up a test scene tonight.

By the way, for information.... when using DepthCue with reflections (e.g. water) there is a problem: the z-depth used to calculate the fog density is measured to the reflecting surface, not to the reflected objects. In the above image, for example, the reflection of the tree has less fog the closer the reflecting surface gets to the camera. This is clearly wrong, and I have not (yet) found a way around this, other than using volume.

That's still kinda cool, IsaoShi.  Gives it a surreal effect, however I can see how it would not work  well and would require some postwork for realism.  Maybe a future version will allow the effects to present to reflection too.

DA

It's actually more noticeable on the far cylinder and sphere test props than on the tree.

But going back to the idea of making the fog thicker at top or bottom...

I suggested using the Y-component of a P node to control the DepthCue Distance parameters, but I think it would be much easier to control the DepthCue Colour. Fading the colour to black would reduce the fogging effect. I'll try this out when I get home this evening, if I'm allowed -- it's not my turn to be she who must be obeyed....

Well, yes... with some node knitting, using the P-Node to control DepthCue colour.

This shader applies DepthCue from a given minimum height upwards - the opposite of a ground fog, I suppose. It's okay for proof of concept, but not very convincing.

For some reason I'm getting darkening of the original (non-DepthCued) render at low heights and greater distances from the camera. I'm clamping the DepthCue colour to prevent it going negative below the minimum height, so i don't really understand why it's doing this.

More work needed... but not now.

Quote - > Quote - Can you make it thicker at the top or bottom?

Well, yes... with some node knitting, using the P-Node to control DepthCue colour.

This shader applies DepthCue from a given minimum height upwards - the opposite of a ground fog, I suppose. It's okay for proof of concept, but not very convincing.

For some reason I'm getting darkening of the original (non-DepthCued) render at low heights and greater distances from the camera. I'm clamping the DepthCue colour to prevent it going negative below the minimum height, so i don't really understand why it's doing this.

More work needed... but not now.

The fog is a blender. The fog color is value 2. The unfogged render color is value 1. The blending value is the linear distance from the camera, scaled according to the start and end settings.

So - at maximum the color is 0% actual render, and 100% black.

You were thinking that the fog color is added. It isn't. It's blended.

The blending equation is:

(1-f) * Value_1 + f * Value_2

where f in this case is Clamp((d - start) / (end - start)).

Thanks, BB, for pointing out what I couldn't see staring me in the face. Goodness knows where I got that idea from... it doesn't look anything like colour addition.
Back to the drawing board... using the distance settings this time.

I would find this much easier to do using Volume instead of DepthCue, because Volume has a convenient Density parameter.

The math is tricky here. I'd use matmatic.

Are you trying to set up a fog layer with increasing density above a certain altitude?

Quote - Are you trying to set up a fog layer with increasing density above a certain altitude?

That's what I was attempting to do, BB. The OP's question was not specific in this respect, he just asked whether it could be made thicker at the top or the bottom.

The way I tackled this problem was to bodge the Start and End distance based on the P-node Y-component. But I'm too lazy to work out a formula that also takes into account the camera height (is it within or outside the fog 'layer'?), so I would be inclined to forget DepthCue for this and use Volume instead.

However, there are 7 key numeric parameters that must be adjusted for the scale of the props you're dealing with and the position of the camera. I despair of ever being able to explain the effect of these 7 values to normal people. Even though the math is pretty straightforward add, subtract, multiply, and divide, there is a lot of it.

I would have to make a parameterized version that has many more nodes, which could reduce the number of control parameters a user would have to deal with to 4 instead of 7.

I'm not sure anybody would find it useful.

I suppose a script could be written that would measure all the props and camera location and set the shader up automatically.

I tested with the Dystopia city props. These are miniatures - not full size. The camera here is only 10 inches above the ground, so it's clear that the numbers I'm using would have to be completely different for a full sized scenario.

Note: I know - there should not be distinct shadows. I didn't bother setting up a legit lighting regime for this scenario.

Excellent result. My meagre effort had four key parameter nodes. I'd like to see how you approached this... any chance we can just see the script (assuming you did it in Matmatic)? No explanations needed.

Funny enough, I decided to wing it in the material room. Sometimes I like to do math in my head, just because it is hard.

I'll post a screen shot.

Later I'll make a script.

How would a person get ground fog? The creepy crawly snaking along the ground ground fog? course it doesn't really have to snake...

I explain this here:

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3412622&ebot_calc_page#message_3412622

Render by AdamaKnight using my ground fog shader.

I really should of paid attention in Algebra and math in school..... LOL

I second that Lzy.

Quote - I second that Lzy.

Im not that much of a genius, which is funny, I work in the mortgage industry. haha. I am lucky I can keep FHA and Conventional guidelines straight.

 Remember it's also possible to apply a "mask/gel" to the fog. I usually plug a turbulence into it, gives a sort of swirly fog :)

An example is on this promo pic where I also used a brownish fog colour http://www.renderosity.com/mod/bcs/index.php?ViewProduct=75257&vendor=83499

Attached Link: Cave tests

So there's a way to make it flat, low to the ground, what about getting it up into the air... say like... a smokey room in the DH Retreat without dropping the retreat to ground level.

That's part of what was causing me confusion on how to make the atmosphere work, because the scene I was experimenting with was using the retreat and I hadn't dropped the retreat's floor to ground level, because I wanted the impression of height through the windows. I'd create the smokey room atmosphere, then render and not see any smoke haze.

In the shader screen shot I showed, with all the annotations in yellow, at the bottom left, it says:

Bottom of fog layer at 3 inches.

Change that to whatever you want to be the bottom of the fog layer.

Okay one more little question for now... lets say I make all these little adjustments and like them, and want to save them for furture use... how would I do that?

Quote - Okay one more little question for now... lets say I make all these little adjustments and like them, and want to save them for furture use... how would I do that?

Since it's made in the MAT room it should be possible to save it as a Material *(or Material Collection, I'd do both just to be sure)

The thing is the atmosphere isn't added to a new object in the scene as normal materials are.. but saving it as an MC6 ought to work still :)

It's a material. Save it like any other material - in the material room, under the materials category. You probably want to make a folder for your fogs.

I don't think it's knowing math, it's knowing how to apply it... which they don't always teach.