Root Nodes

Poser includes the following nodes, which, combined and linked to root nodes, can create virtually any shader you can imagine. Nodes are divided into several groups: Math, Lighting, Variables, 3D Textures, and 2D Textures. Each group and its shaders are discussed in this chapter.

All shaders include a root node, which can be modified using added nodes that modify the root node. Thus, the root node is itself a complete shader. The Material room has four root nodes:

Material, Background, Light, and Atmosphere. Let’s examine these nodes further.

Poser provides three different types of material root nodes that work with the FireFly and SuperFly renderers. By default, each material initially uses a PoserSurface node for a new material, in order to maintain backward compatibility to legacy content. The PoserSurface node is initially designated to be sent to both the FireFly and SuperFly renderers.

The PoserSurface node is initially sent to both the FireFly and SuperFly renderers.

When you use the New Node > Root > PhysicalSurface or CyclesSurface command to add a second material root node, you will be able to designate which of the two material root nodes is sent to which renderer. Though each of the three material root nodes can work with either renderer, the most common choice will be to have the PoserSurface node sent to the FireFly renderer, and the PhysicalSurface or CyclesSurface sent to the SuperFly renderer.

When you add a second material root node you can direct each material root node to either the FireFly or SuperFly renderer.

Root Material (PoserSurface) Node

The PoserSurface node contains all of the attributes required to create a complete shader for almost every material group in your scene (figures, props, hair).

Poser Surface Node.

•Firefly Root: Choose this option if you want the output of this root node to be sent to the FireFly Renderer.

•Superfly Root: Choose this option if you want the output of this root node to be sent to the SuperFly Renderer.

•Diffuse Color: The Diffuse_Color attribute is the surface color that is multiplied through any light striking the object.

•Diffuse Value: The Diffuse_Value attribute defines the strength of the diffuse color, where 1=100%.

•Specular Color: The Specular_Color attribute defines the color of the object’s highlight.

•Specular Value: The Specular_Value attribute defines the strength of the specular color, where 1=100%.

 

Highlight Size: The Highlight_Size attribute defines the quantity of micro-facets on the object surface. Micro-facets are tiny imperfections that are invisible to the human eye, yet effect the way light is reflected off the surface. Very smooth surfaces (such as glass) have very few imperfections and produce a very sharp specular highlight. Surfaces such as paper have extremely high numbers of imperfections in their surface and thus produce subtler specular highlights.

•Ambient Color: The Ambient_Color attribute defines the color that a surface has when it receives no light. This can be used to simulate overall ambient light or to create self- illuminating surfaces. Note that the ambient color of a surface will also bounce off other surfaces when rendering with indirect light enabled.

•Ambient Value: The Ambient_Value attribute defines the strength of the ambient color, where 1=100%.

•Transparency: The Transparency attribute defines the object’s opacity, where 1=fully transparent.

•Transparency Edge: The Transparency_Edge attribute defines the object’s transparency at its edges. For example, a glass appears opaque at its edges.

•Transparency Falloff: The Transparency_Falloff attribute defines how the transparency changes as it moves towards the object edge. Smaller values create a sharper edge and vice versa.

•Translucence Color: The Translucence_Color attribute is the color of light passing through the object.

•Translucence Value: The Translucence_Value attribute defines the strength of the translucent color, where 1=100%.

•Reflection Color: The Reflection_Color attribute allows you to specify a reflective color. This is a good input for connecting other nodes to control reflections.

•Reflection Value: The Reflection_Value attribute defines the strength of the reflective color, where 1=100%.

•Refraction Color: The Refraction_Color attribute defines the color of light refracted by the current object.

•Refraction Value: The Refraction_Value attribute defines the strength of the refraction color, where 1=100%.

•Bump: The Bump attribute defines the amount of bump in the material.

•Displacement: The Displacement attribute defines the amount of displacement in the material.

•Alternate Diffuse: The AlternateDiffuse attribute provides an alternate input for diffuse lighting. Use this channel for strand-based hair and anytime you wish to use custom diffuse lighting.

•Alternate Specular: The AlternateSpecular attribute provides an alternate input for specular lighting. Use this channel for strand-based hair and anytime you wish to use custom specular lighting.

•Reflection Lite Mult: Checking the ReflectionLiteMult checkbox multiplies the total color through the amount of diffuse lighting hitting each point on the surface. This automatically darkens reflections in areas not seen by lights. On by default.

Reflection Kd Mult: Checking the ReflectionKdMult checkbox automatically tints the reflection color by the surface’s diffuse color value. Off by default.

In SuperFly, Reflection Lite Mult or Reflection Kd Mult will disable any lighting nodes plugged into the Reflection channel.

•Gradient Bump: Previous versions of Poser used a proprietary file format for bump maps (*.BUM). If you want to use these older file types in Poser, connect an image map node to the Gradient_Bump attribute and load your desired *.BUM file into that node (see Image Map (Image_Map) for information on loading images). You cannot use *.BUM files with the FireFly renderer. The Gradient Mode option also allows you to select one of two types of normal maps.

•Gradient Mode:

•Gradient Bump: Choose this option to use with a grayscale bump map image.

•Tangent Space Normal Map: Tangent space normal maps have a mostly blue appearance. The normals in a tangent space map are always considered “up” even if it is not true in world space.

•Object Space Normal Map: Object space normal maps are rainbow-colored in appearance. The normals are pointing in their actual directions.

•ShadowCatchOnly : Checking the ShadowCatchOnly checkbox allows transparent surfaces to catch shadows, as opposed to letting the shadows appear on the opaque surface behind them. In other words, this option will treat transparent surfaces as opaque, only in terms of their interaction with shadows. A prime use of this feature would be if you wish to render only a figure and its shadow; you could set up the floor as a transparent surface by using the ShadowCatchOnly feature to show your figure’s shadow on the transparent floor, and render (without the background). The floor will be invisible except for the shadow laying on it, so the only things in your rendered scene will be the figure and its shadow.

•ToonID: By default, selecting the Toon Outline option causes an outline to appear around each separate material on the figure or object. Depending on how the figure is setup, this may lead to too many outlines. In such a case, you can adjust the Toon ID assignment on the root node of the material, to reduce the number of outlines drawn. Assigning the same ID to multiple materials means that the render engine will not draw separating outlines between those materials.

•Normals_Forward: Checking the Normals_Forward checkbox will flip the surface normal to point towards the camera (or towards the ray in case of raytracing). Light for indirect lighting (IDL) is also cast in the direction of the normals. Use this option to avoid shading artifacts on double-sided polygons.

Custom Outputs: Use the Custom_Output_1, Custom_Output_2 and Custom_Output_3 connectors to define material properties that you want to output to Photoshop layers. If there is no connection to these inputs in the Poser Surface node, the output to a layered PSD file will be Diffuse only, Specular only, and Shadow only, respectively for Custom Output 1, 2, and 3. For more information, see Rendering Layered PSD Files.

•Volume: Input from the Volume node, discussed in Volume.

•Geometric Edge: Allows you to set the width of a geometric edge line for the current material.

•Geometric Edge Color: Allows you to set the color of a geometric edge line for the current material.

Physical Surface Node (PhysicalSurface)

The Physical Surface node provides standardized connections that are typical of those used by physical based renderers (such as Cycles) and texture generating utilities (such as Quixel Suite or Substance Designer/Painter).

Physical Surface Node.

Render Engine Selection:

•Firefly Root: If the material also contains a PoserSurface Node or Cycles Surface Node, choose this option if you want the output of this root node to be sent to the FireFly Renderer.

•Superfly Root: If the material also contains a PoserSurface Node or Cycles Surface Node, choose this option if you want the output of this root node to be sent to the SuperFly Renderer.

Color

 

The Diffuse color is the primary surface color of the current figure or prop. When creating PBR textures in programs such as Quixel or Substance, color textures may also be referred to as Albedo maps, and are typically flat colors with no baked in shadows or highlights.

To change the Diffuse color, click on the Color chip. This will bring up the Poser Color Picker, where you can select your desired color. If you wish to access the system Color Picker, simply click on the RGB bar at the top right corner of the Poser Color Picker.

•If not using a diffuse or albedo texture, set the Color chip to the color that you want to assign.

•Since the Physical Surface node is designed for use with PBR textures,you will get the best results if your color map does not contain baked in highlights and shadows. Those effects will come from other maps described below.

•When using a Diffuse/Albedo map, set the Color chip in the Physical Surface node to white, unless you want to tint the texture map with a different color.

•The Gamma value in the Texture Manager for the Color map should be set to Use Gamma Value from Render Settings (which is set to 2.2 by default).

Use Color input to define the color of the object.

Transparency

Transparency allows light to pass through a figure or object, so you can see through it. The higher a transparency value, the more of the surrounding environment is visible through the object’s surface. If no light is reflected on an object, 100% Transparency and Edge settings make it invisible.

When a Transparency map is applied to an object, its texture interferes with the transparency of the object. For example, a checkerboard map results in an object that is alternately transparent and solid. You can thus use textures as Transparency maps.

•Enter a value between 0 (fully opaque) to 1 (fully transparent), or attach a black and white or grayscale transparency map to the input. Set mode to Transparency.

•If using a transparency map that uses black for transparent areas and white for opaque areas (typical for transparency maps in Poser), set Transparency value to 1, and set Transparency mode to Opacity.

•Gamma value in the Texture Manager for the Transparency Map should be set to Custom Gamma Value of 1.

•If transparency is not used, set Transparency setting to 0.

 

 

Transparency 0% - 25% - 50% - 75% - 100%.

•Choose one of the following Transparency Mode options:

•Opacity: Choose Opacity if your map uses black for transparent areas and white for opaque areas. (Typical for maps used in Poser)

•Transparency: Choose Transparency if your map uses white for transparent areas and black for opaque areas.

•Colored Transparency: If you have a color map attached to the Color input of the material, checking this option will enhance the transparency with color. This is good for items such as stained glass windows.

Roughness

•Roughness: Input that defines the glossiness or roughness of a material. Can be used to add scratches to a surface.

•Enter a value between 0 (very glossy) or 1 (more flat)

•If using a grayscale map for roughness, darker areas in the map will appear more glossy, and lighter areas in the map will appear rough or flat.

•Gamma value in the Texture Manager for the Roughness texture should be set to Custom Gamma Value of 1.

 

Roughness  0% - 25% - 50% - 75% - 100%.

 

Specular

•Specular: The Specular setting controls the highlights in your object. They appear as sharp bright spots in an object. The value you enter controls the amount of specularity. You can also attach a map to the input to control color or brightness.

Specular 0% - 25% - 50% - 75% - 100%.

Metallic

•Metallic: The Metallic property controls whether or not a material is made of metal. A value of zero is fully non-metallic, and a value of 1 is fully metallic.

•Metallic maps

Metallic 0% - 25% - 50% - 75% - 100%.

Metallic maps are usually used in conjunction with Roughness maps in PBR textures, in lieu of Specular and Gloss maps.

Emission

•Emission: Defines the color of light that is emitted from the object. This color is independent of the object color.

•Emission Strength: Controls the strength of the emission effect. A value of 0 (or black in a map) indicates no emission. A value of 1 (or white in a map) indicates full emission strength.

Emission. White emission color with 0% - 25% - 50% - 75% - 100% strength.

Bump

A Bump map is a special image, wrapped around the object, that works with the scene lighting to give the appearance of 3D texture on an otherwise smooth object. Bump maps can be used on individual objects or parts of a figure to emulate any manner of textures, from wrinkles and pores in skin, to raised patterns in clothing or props, to cracks and bumps in stone.

Bump maps are typically grayscale maps, with darker areas being more recessed and lighter values appearing to be raised. They do not alter the geometry. As a result, the effect is more pronounced in areas that directly face the camera, and show little effect when the geometry is perpendicular to the camera. In other words, if you apply a Bump map to a sphere, the surface will seem rough while the edges remain smooth.

•This connection uses grayscale bump maps. For normal maps, see the following topic. Old style Poser BUM maps should not be connected to the bump input.

•Gamma value in the Texture Manager for the BumpMap should be set to Custom Gamma Value of 1.

•If Bump map is not used, set Bump setting to 0.

•The strength of bump and displacement maps is expressed in real world units (whichever unit is set under Edit > General Preferences). Please note that with the default unit of Feet very small values already yield a strong bump or displacement effect.

Bump 0% - 25% - 50% - 75% - 100%.

Normal Map

A normal map is an image, wrapped around the object that works with the scene lighting to give the appearance of 3D texture on an otherwise smooth object. Normal maps can be used on individual objects or parts of a figure to emulate any manner of textures, from wrinkles and pores in skin, to raised patterns in clothing or props, to cracks and bumps in stone.

•The Normal map input of the Physical Surface node expects a tangent space normal map (which is mostly shades of blue). World or Object Space normal maps should not be used.

•To load a Normal Map, from the Material Room > Material Palette, Advanced tab, connect the Image Node containing a normal map to the Normal channel on the Physical Surface Node.

•Leave the Strength value set to 1.

•Gamma value in the Texture Manager for the Normal Map should be set to Custom Gamma Value of 1.

No normal map - Tangent Space normal map.

Displacement

•Displacement: As the displacement value increases, geometry is displaced farther from the actual shape of a model. In a displacement map, dark values generate lower displacement, and lighter values generate more displacement.

Displacement 0% - 5% - 10% - 15% - 20%, level 0 subdivision.

 

Displacement 5%, at level 0, 1, 2, 3, and 4 subdivision.

Volume

•Volume: Input from the Volume node, discussed in .

Examples of Volume Absorption, Scatter, and Emission colors.

Scatter

•ScatterDistR, ScatterDistG, and ScatterDistB: Scatter distance is the average distance into the object that a ray will travel before it scatters. Skin is typically 3 to 5 mm. Chicken soup would be something like 15 to 20 mm.

•Scatter IOR: Enter an Index of Refraction value for the selected material.

•Scatter Scale: Enter a scale factor for the SSS. The default is set to .01.

•Scatter Anisotropy: Controls the directionality of subsurface scattering.

•Scatter_Group: Scatter groups are used to prevent objects from bleeding through each other. For example, brightly colored lipstick might bleed into surrounding lips, so you should set the lips to a different scatter group than the rest of the head.

•Subsurface Method: Choices are Burley, Walk, and Walk Fixed. Walk is recommended for most cases.

Cycles Surface Node (CyclesSurface)

The Cycles Surface Node replicates the surface node that is used in Blender’s Cycles renderer. This can be used in conjunction with the Cycles nodes (discussed in Cycles Nodes) to create materials similar to those created in Blender. Consult the Blender documentation for further information on usage of Cycles surface and material nodes.

Cycles Surface Node.

Other Root Node Types

In addition to the three types of Material root nodes, Poser also offers root nodes that are specific to the background, lights, or atmosphere in your scene. These root nodes are described in the following sections.

Root Background Node

To display the root background node, choose the Background object from the Object selection menu in the material room Edit view.

The root Background node contains all of the attributes required to create a complete shader for your scene’s background and has the following attributes:

Root Background Node.

•Color: The Color attribute allows you to choose the background’s base color.

•Diffuse Color: The Diffuse_Color attribute is the surface color that is multiplied through any light striking the object.

•Specular Color: The Specular_Color attribute defines the color of the object’s highlight.

•Highlight Size: The Highlight_Size attribute defines the size of the highlight.

•Bump: The Bump attribute defines the amount of bump in the material.

•Cast Light: Check this option to allow the background to cast light (SuperFly renderer only)

Background Diffuse_Color, Specular_Color and Bump are not supported in SuperFly.

The final render will always display whatever is attached to the Color channel of the Root Background node. However, if you wish the same image or color to appear in the preview render, you must also attach it to the BG Picture or BG Movie node.

The Root Background node initially has five additional node types that are specifically designed to work with the Background root node.

BG Color

BG Color Node.

•Color: The Color attribute allows you to choose the background’s base color.

BG Environment

The BG Environment node is used to light your scene using an environment map image file as a texture. This node is the same as the Cycles > Texture > Environment Texture node discussed in Environment Map Nodes.

 

BG Environment Node.

•Color: RGB Color output, connect to the Color input of the Background root node.

•Alpha: Alpha output from the image. If the image has no alpha channel, output is white.

•Vector: Texture coordinate for texture look-up. If this socket is left unconnected, the image is mapped as environment with the Z axis as up.

•Projection: Choose Equirectangular  (projects from an equi-rectangular photo) or Mirror Ball (projects from an orthographic photo or mirror ball).

•Image: Click to select your image source.

To see an example of this node in use, open either the Mondello Beach or Wide Street scene from the startup launcher. These scenes use the BG Environment node to project an image on to an environment sphere.

When the environment sphere is included in the scene, open the material editor and choose the Background object in the Material Editor. The preview window will display the HDRI image mapped onto the inside of the environment sphere. The following nodes are connected to the Background root:

•Add a Cycles > Input > TextureCoordinate node.

•Add a Cycles > Vector > Mapping node.

•Connect the Generated output from the TextureCoordinate node to the Vector input of the Mapping node.

•Set the Rotation value in the Mapping node to 0.000000, -1.570000, 0.000000

•Set the Scale value in the Mapping node to -1.000000, 1.000000, 1.000000

•Connect the Vector output from the Mapping node to the Vector input of the BG Environment node.

•Connect the Color output from the BG Environment node to the Color input of the Background root node.

Environment sphere background shader.

Next, select the Environment Preview from the object menu in the Material room. The same image used in the Background is added to its default material to cast light into the scene. For this, you use an image map node with the same HDRI image assigned. The Color output of the image map is connected to the Emission connection in the Physical Surface root node.

Environment prop emission shader.

Finally, select the Preview Light object from the Object menu in the material room. This is the third place where the HDRI image is referenced. The HDRI image map node is connected to the Color input of a root light node. Color is set to white, and Diffuse and Specular are set to black on the root light node.

Environment  preview light

Because the HDRI image is referenced in three places for the envirosphere, the easiest way to change the image used in this HDRI environment is as follows:

1.Switch to the material room and select the Background from the list of objects at the top of the Material Editor.

2.On the BG Environment node click the texture to open the Texture editor.

3.Click the Browse button and select any HDR Image you want to use as an environment.

4.Click the "Replace all identical maps" button at the bottom of the Texture manager.

5.Choose to replace all identical maps in the Scene.

BG Movie

BG Movie Node.

•Video Source:  Select the video source you want to use in the background.

•Auto Fit: Check this option if your video source is rectangular (non-square). The video will be stretched to match the aspect ratio of the movie you selected. The image will be scaled from its center.

•U Scale: Enter a scale factor for the width of the video. For example, if the width of the video is 20% wider than it is high (landscape style), enter 1.2 for the U scale value. The left side of the image remains in its original position, and the image will be scaled toward the right. If Auto Fit (above) is checked, you can leave this at its default value of 1.

•V Scale: Enter a scale factor for the height of the video. For example, if the height of the video is 20% higher than it is wide (portrait style), enter 1.2 for the V scale value. The bottom of the image remains in its original position, and the image will be scaled toward the top. If Auto Fit (above) is checked, you can leave this at its default value of 1

•U Offset: Enter an offset, in percentage, to position the movie lower (negative value) or higher (positive value). 

•V Offset: Enter an offset, in percentage, to position the movie leftward (negative value) or rightward (positive value). 

Importing movies with the File > Import > Background Movie command will automatically connect the BG Movie node to the Color output of the Background root node, and adjust the UV Scake and UV Offset settings as needed. to display the background movie at the correct aspect ratio.

•Texture Coords: Available texture coordinates are UV, VU, XY, XZ, ZY, and Mapper.

•Image Mapped: Available options are None, Alpha, Clamped, and Tile.

•Background: Click to choose a background color that will show through invisible (alpha) areas.

•Global Coordinates:

•Mirror U:

•Mirror V:

•Texture Strength: Click to specify the strength of the movie source. The default value is 1 which will be fully opaque. Values lower than 1 will be partially transparent, and rendered over the Color as set in the Background root node.

•Frame Number:

•Loop Movie: Check this option to restart playback of the movie from the beginning after it reaches the end. Uncheck the option to stop playback once it reaches the end. BG Picture

BG Picture Node.

•Image Source: Select the image source that you want to use for the background.

•Auto Fit: Check this option if your image source is rectangular (non-square). The image will be stretched to match the aspect ratio of the image you selected.

•U Scale: Enter a scale factor for the width of the image. For example, if the width of the image is 20% wider than it is high (landscape style), enter 1.2 for the U scale value. If Auto Fit (above) is checked, you can leave this at its default value of 1.

•V Scale: Enter a scale factor for the height of the image. For example, if the height of the image is 20% higher than it is wide (portrait style), enter 1.2 for the V scale value. If Auto Fit (above) is checked, you can leave this at its default value of 1.

•U Offset: Enter an offset, in percentage, to position the image lower (negative value) or higher (positive value). 

•V Offset: Enter an offset, in percentage, to position the image leftward (negative value) or rightward (positive value). 

Importing images with the File > Import > Background Picture command will automatically connect the BG Picture node to the Color output of the Background root node, and adjust the UV Scake and UV Offset settings as needed. to display the image at the correct aspect ratio.

•Texture Coords: Available texture coordinates are UV, VU, XY, XZ, ZY, and Mapper.

•Image Mapped: Available options are None, Alpha, Clamped, and Tile.

•Background: Click to choose a background color that will show through invisible (alpha) areas.

•Global Coordinates:

•Mirror U:

•Mirror V:

•Texture Strength: Click to specify the strength of the image source. The default value is 1 which will be fully opaque. Values lower than 1 will be partially transparent, and rendered over the Color as set in the Background root node.

•Filtering: The Filtering attribute allows you to select one of three options for texture filtering on the selected image map. These options are: None--no texture filtering; Fast-- high-speed texture filtering; Quality--high-quality texture filtering; Crisp--provides more aliasing for increased crispness.

Black

Black Node.

•Color: The Color attribute allows you to choose the background’s base color.

Root Light Node

A root Light node appears whenever you have a light selected. Each light in your scene has its own root Light node, which has the following attributes:

Root Light Node.

•Color: The Color attribute allows you to choose the light’s base color.

•Intensity: The Intensity attribute defines the light’s brightness.

•Angle Start: The AngleStart attribute defines the start of the light cone (in degrees) for spotlights.

•Angle End: The AngleEnd attribute defines the end of the light cone (in degrees) for spotlights.

•Angle Expo: The AngleExpo attribute controls how the light fades towards the edge of the light cone (falloff).

•Diffuse: The Diffuse attribute allows you to create lights that use only a diffuse component to light the scene.

•Specular: The Specular attribute allows you to create lights that use only a specular component to light the scene. You can create specular only lights by setting the color in the specular channel to black. You can also create a negative light source (a light source that darkens or negates certain colors in the areas of the scene lit by this light) by setting the Specular value to zero (i.e., black) and setting the light’s Intensity to -1. Then the Color and Diffuse channels can be adjusted to reduce certain aspects of light.

•Image Resolution: The Image Resolution attribute specifies the width and height of the light probe to be sampled. You can attach a light probe of any size, and then adjust the resolution to suit your needs. Note that higher resolutions require more processing time, whereas with extremely low resolutions you will lose image quality. 256 is a reasonable default resolution for most light probe images.

•IBL Contrast: The IBL Contrast attribute allows you to modify the level of contrast in the incoming light probe image. The default value of 3 for this attribute is intended for use with Low Dynamic Range (LDR) images. For High Dynamic Range (HDR) images, the best IBL Contrast setting would be 1.

Root Atmosphere Node

The Root Atmosphere node contains all of the attributes required to create realistic atmospheric effects such as fog, haze, etc. in your scenes.

Root Atmosphere Node.

•DepthCue_On: Checking the DepthCue_On checkbox enables depth cueing, which varies all surface material colors from their original lit colors to the specified depth cue color

(see below). This gives an effect similar to enabling the Depth Cueing option in the Document as described in Using Depth Cueing.

•Volume_On: Checking the Volume_On checkbox enables volumetric effects. You can enable depth cueing and/or volumetric effects individually.

•DepthCue_Color: The DepthCue_Color attribute specifies the color to use when applying the depth cueing.

•DepthCue_StartDist: The DepthCue_StartDist attribute specifies the distance from the current camera at which the depth cueing effect begins. This distance is not necessarily displayed in Poser distance units.

•DepthCue_EndDist: The DepthCue_EndDist attribute specifies the distance from the current camera at which the depth cueing effect ends. This distance is not necessarily displayed in Poser distance units.

•Volume_Color: The Volume_Color attribute specifies the color of the volumetric effect. This color is multiplied with the color of the lights in your scene. To use the lights’ colors for the volume, set this color to white.

•Volume_Density: The Volume_Density attribute controls the strength of the volumetric effect. This effect is multiplied by each light’s Atmosphere Strength attribute. If this attribute is set to 1.0, the selected light will cast atmospheric effects equal to this attribute and so forth. Please refer to Light Properties.

•Volume_StepSize: The Volume_StepSize attribute specifies the distance between rendering samples taken through the volume. Lowering this value increases the quality and requires increased render time.

•Volume_Noise: The Volume_Noise attribute adds a random factor added to the sample that can help balance out the effect of larger step sizes (see previous attribute).

You can connect nodes to the color and density attributes for more complex effects.

Without volumetric rendering (no fog) on left; With volumetric rendering (with fog) on right.
 

Bright infinite lights can wash out volumetric effects unless you use a very low density. Volumetric effects are most successfully used with both spotlights and carefully controlled density numbers. Also, Volumetric lighting effects only appear over a rendered object. They do not appear over an empty background, even when a background shader is in place. You need at

Root Node Help

Some node attributes have a question mark (?) icon next to them. Clicking this icon opens help for that channel. This help is also available by navigating the Material room help window (available by clicking on the (?) icon at the top right of the Shader window.

For example, if you click the question mark that appears in the Alternate Diffuse channel in the PoserSurface node, it opens a Room Help file that explains more about the Alternate Diffuse nodes.