Materials, Shaders, and Textures

The Materials UI contains a comprehensive set of options and controls for setting the shader type, blending mode, shading parameters, color factors, and texture mapping and blending.

A material defines how the layer and its associated surface object appears. It defines how it interacts with lights, how it reflects light back to the view, and how it blends in with the rest of the scene. You can choose one of four shader types to set the basic material properties for a given layer and choose from a wide selection of blending modes to define how the current layer is blended with the scene element lying behind it (with respect to the view).

In addition, each material node has five input tabs, or channels, that you can use to assign one or more sources to apply textures to an object. The main material channel defines a layer's base material and texture mapping, and is always used. You can optionally connect sources to the other inputs on the material node to define a bump map, as well as radiosity, reflection, or refraction environment maps, depending on the shader type selected. To set material color vakues. see Setting Material Colors

Textures are 2D images that can be wrapped around an object's surface, much like a piece of paper wrapped around an object. The information displayed on the object's surface depends on the type of texture map used. In bump maps or normals maps, RGB or luminance values are used to give the surface the illusion of peaks and valleys. In radiosity maps, the object appears to blend in the source image's radiosity. This is useful for creating realistic lighting effects without the high rendering cost associated with raytracing or radiosity.

Blending Modes

Blending modes are available with all shader types. A blending mode defines how the color of one layer is blended with the color of the layer or part of the scene lying behind it (relative to the Player). You can animate and apply expressions to blending modes—see Animation and Expressions.

There are two categories of blending modes:

Software: Lets you select the blending mode used by the software renderer. If you selected Interactivity in the Player Options to enable the hardware renderer for fast results while you work, you can set the Software blending mode to Follow HW. This ensures that the software and hardware renderer produce almost exactly the same results. The Follow HW option is selected by default. Because the hardware and software renderer use different methods to calculate results, it is recommended that you perform all transformations using the hardware renderer, but verify your results using the software renderer.
Hardware: Lets you select the blending modes used by the hardware renderer, which can only reproduce a subset of the blending mode effects available to the software renderer.

For how to set basic shading parameters, see Basic Shading Parameters.

Blending Mode	Description	SW	HW
Follow HW	Set results to follow the hardware renderer.	X
Normal	Maintains the normal colors for the layer.	X	X
Premultiplied	Multiplies the colors of the current layer with the alpha of the layer behind it.	X	X
Dissolve	Randomly dissolves pixels of the current layer over the layers behind it.	X
Add	Adds the Red, Green, and Blue values of the current layer's pixels to the layers behind it. The resulting composite can make the layer's pixels appear very bright, especially over a bright background.	X	X
Subtract	Subtracts the Red, Green, and Blue values of the current layer's pixels from the layers behind it. The resulting composite can make the layer's pixels appear very dark.	X	X
Multiply	Multiplies the pixel values of the current layer with the pixels in the background, and clips all RGB values at 255. The overall effect is similar to drawing with a colored marker over an image: it darkens and colorizes at the same time using the current layer imagery.	X	X
Spotlight	Shines a spotlight uniformly on the current layer.	X	X
Spotlight Blend	Shines a spotlight on the layer and blends with the layer behind it.	X	X
Screen	Combines the pixels in the current layer with the pixels in the background so that the current layer is composited over the layers in the background with lighter pixels than before. The effect is similar to the photographic technique of combining two slides in a slide “sandwich” and then reshooting them. Screen mode is the inverse of Multiply mode.	X	X
Overlay	Displays the image through a gel of the current layer. It combines the colors of the current layer with those of the layers behind it to create new tints based on these results. It boosts contrast and color saturation at the same time.	X
Soft Light	Shines a soft, diffuse light associated with the current layer onto the layers behind it. It reduces the contrast levels in the image.	X
Hard Light	Shines a harsh light associated with the current layer onto the layers behind it. It primarily affects areas of detail, and greatly reduces the contrast levels in the image.	X
Darken	Composites only the pixels of the current layer that are darker than the pixels of the layers behind it.	X	X
Lighten	Composites only the pixels of the current layer that are lighter than the pixels of the layers behind it.	X	X
Difference	Displays the difference between the pixels in the current layer and the pixels of the layers behind it. When a brighter pixel is subtracted from a darker pixel, the positive value of the color is used and results in bright color shifts. The layer order is not significant, as both layers contribute nearly equally to the result.	X
Exclusion	Creates an effect similar to Difference, but lower in contrast and resulting in a grayer image. The layer order is not significant, as both layers contribute nearly equally to the result.	X	X
Hue	Changes the hue of the current layer to the hue of the layers behind it. This effectively makes the current layer take on the “tint” of the elements in the background of the composite.	X
Saturation	Changes the saturation of the current layer to the saturation values of the layers behind it. (This differs from Saturate, which uses the saturation of the current layer to increase that of the layers behind it.)	X
Color	Changes the hue and saturation of the current layer to the hue and saturation values of the layers behind it.	X
Luminance	Changes the luminance of the layers in the background of the composite to the luminance value of the current layer.	X

Material Color Settings

You can set color factors for each texture channel available for the type of shader you select. If you are working with a Standard shader, you can also set color factors for ambient and specular lighting effects. The colors you set are multiplied with the colors of the input source image connected to that channel. The Shadow Matte shader has no color factors.

NoteYou can choose to add a layer without a source to your composition. For example, if you want to add a colored ball to your scene, you can simply create a layer and set its color in the Materials tab. In this case, the main color would be the color you set.

Color	Description
Main	Sets a color to modulate the main material color. The Main color is a diffuse color that the light scatters in all directions, so that the layer surface appears to have the same brightness from all viewing angles. Available for all Shaders except for Shadow Matte.
Ambient	Sets a color to modulate the color of areas of the object that are shielded from direct light sources, but are still visible, due to non-directional ambient lighting that exists in the scene. Available in the Standard shader only.
Specular	Sets the color of shiny highlights on the layer surface. It is usually set to white or a brighter shade of the main color. Available in the Standard shader only.
Emitted	Sets a color to modulate the color emitted from an object in the scene. Available in the Standard shader only.
Reflective	Sets a color to modulate the color of layer surfaces with reflective properties and/or reflection maps applied. You typically set a grayscale value, with white being reflective, and black having no reflectivity.
Refractive	Sets a color to modulate the subtle changes in color that occur as light passes through an object where transparency or translucency is incorporated. Black has no refractive properties.
Radiosity	Sets a color to modulate radiosity effects applied to your scene. Radiosity effects add a high degree of realism to images as it considers all light in an entire environment and simulates what happens when rays of light hit an object. Some stick (where a surface is opaque and absorbs the light), and others are reflected and refracted. These rays then go on to illuminate other surfaces before reaching the human eye. This yields indirect lighting and color bleeding effects ideal for global illumination.

Using Texture or Environment Maps to Control Surface Attributes

The Main texture channel defines the surface's general appearance, but if your main texture is not enough to give you the look you want, you can add more texture maps. Each Material node has five texture channels that you can use to apply texture and environment maps to refine the appearance of an object's surface. You can set parameters for each channel.

The Main and Bump texture channels let you wrap and position a texture on the surface. By default, the image is clamped to the surface. You can then use placement parameters to position the source image on the surface and apply tiling effects.

The Radiosity, Reflection, and Refraction channels let you apply environment maps to your surface object. The environment maps use their source image to surround the surface with a virtual sphere to simulate an environment, which shows up as reflections on the surfaces of objects with reflective properties. The environment map always covers the sphere exactly once. You can transform your object and see the effects of the environment map change dynamically. Using environment maps is a fast and inexpensive way to achieve highly realistic lighting effects.

Note Material nodes in the Group Schematic always show all five input tabs. However, the number of active input tabs depends on the channels available for the selected Shader type.

Adjust the parameters to control image brightness and texture quality, and in the case of the Main and Bump textures, specify how the texture is positioned on the object. The following parameters are available depending on the channel you selected:

Shader Parameters

Property	Description
Multiplier	Uniformly scales the brightness of the image texture up or down. This is useful for setting the amount that a given texture affects the object's overall look. The default value is 1, but you can overdrive the brightness to achieve specific effects.
Filtering	Sets the quality of the texture image. When a texture is stretched onto an object, it may, depending on the camera position, lose some of its crispness. The rendered can compensate for this, but it may slow the process. Filtering options include: Nearest A box filter and the fastest way to resample an image since it only samples a single pixel of the input image to determine the value of a given pixel in the result image. Produces significant amount of aliasing. Bilinear A separable triangular filter that takes into account more area when resampling. Mitchell Considered one of the best magnification filters for images; has a good balance between ringing and sharpness. Gaussian Good magnification and magnification filter with no ringing, but introduces noticeable softness to the result image. Jinc 2 Offers better sharpness than the Gaussian filter, but at the expense of ringing. Similar to the sinc filter, but with better isotropic qualities, less ringing, and same sharpening and anti-aliasing. Jinc 3 Offers better sharpness than the Gaussian and Jinc 2 filters but at the expense of even more ringing. Similar to the Lanczos filter but with better isotropic qualities, less ringing, and same sharpening and anti-aliasing.
AA Factor	Lets you adjust the trade-off between anti-aliasing and blurriness.
Refract Inx	Sets the amount of refraction for the current layer when using a refractive texture. The higher the value, the greater the amount of light The higher the value, the greater the amount of light dispersion (splitting), which increases the object's brilliance.
Tiling X, Tiling Y	Set the repeat mode. Choose from; Transparent, Edge, Repeat, and Mirror.
U Offset,V Offset	Translates the texture in U and/or V.
U Scale, V Scale	Lets you specify the number of times a texture is repeated over a surface. You can use a non-integer value, such as 2.35.
Rotation	Rotates the texture over a surface.

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