rampShader

If there are ambient lights in the scene, then the color and brightness of those lights is used to control how much the ambient color contributes to the final color of the material.

Causes shadows of transparent objects to be brighter in the center, simulating the focusing of light. 0 gives constant intensity shadows, 1 gives shadows focused in the center.

Note that this is different from the Incandescence attribute in a few important ways. First, glow is added as a post-process at the end of rendering. (Incandescence just makes the surface appear brighter.) Second, glow adds a halo, which incandescence does not.

By default, the color is black, which has no effect on the surface.

Note: although incandescence makes a surface appear to glow, it does not actually act as a source of light in the scene. If there is more than one index in the ramp then the incandescence value will vary with the facing angle.

See also Glow Intensity.

There are three settings, used for different purposes:

Opacity Gain: (the default). Matte values are calculated in the normal way (based on the transparency of the object) then multiplied by the Matte Opacity. (Matte Opacity has a default value of one, by default these attributes have no effect.) With Opacity Gain, you can animate the Matte Opacity value to change the overall transparency of the object when it is later composited.

Solid Matte: This is like Opacity Gain, except that the normally-calculated matte values are ignored in favor of the Matte Opacity setting. The entire matte for the object is set to the value of the Matte Opacity attribute. If there are transparent areas on the object, their transparency is ignored in the matte. Use this setting to composite an object with transparent parts, when you don't want the background to show through them.

Black Hole: The value of Matte Opacity is ignored, and all the matte for this material is set to be transparent. Use this when you are creating substitute geometry in a scene, which is standing in for objects in a background image that you will be compositing with later. Your stand-in objects will 'punch a hole' in the matte. This allows other computer-generated geometry to pass behind your stand-in objects. Later, when foreground and background are composited, the results will be correct, with the background object showing through the 'black hole' areas.

To do Bump Mapping, connect the output of a bump node to this attribute.

Causes the transparency of an object to diminish with its thickness. An object is opaque if its thickness is greater than its Opacity Depth. When the Opacity Depth value is 0, it has no effect (as opposed to making an object entirely opaque). The shader must have some Transparency to show the effect of Opacity Depth. When Opacity Depth is non-zero, transparency controls specularity, reflectivity, and incandescence, which are normally independent of transparency. This makes it easier to create soft, fuzzy objects. Also, if you use a transparency map to create holes in a surface that has specular highlights, set Opacity Depth to a high value instead of creating a matching specular map. Transparent objects cast shadows in the raycaster even if the Opacity Depth value is non-zero.

Tip: Use Opacity Depth to simulate hair, fur, and clouds.

You can map an image or texture or environment map to this attribute in order to make 'fake reflections', which are less expensive than ray-tracing. This is called Reflection Mapping.

Reflection Mapping and raytracing may be used together, in which case the reflection map is used as 'background', and raytraced reflections appear in the 'foreground'.

This attribute is only meaningful if there is a reflection map, or if you are doing Ray Tracing.

Here are some useful values for Reflectivity:

Car Paint: 0.4
Glass: 0.7
Mirror: 1.0
Chrome: 1.0

Note: If you are doing Ray Tracing, and you want other objects in the scene to be seen in reflections, then you must turn on the Visible In Reflections attribute of those objects.

If the Refractive Index is set to 1.0, then light does not bend when it passes through the object. Here are some other useful values for Refractive Index:

Air: 1.0
Water: 1.33
Gasoline: 1.45
Crystal: 2.00
Glass: 1.5
Ice: 1.309
Quartz: 1.6
Ruby: 1.77
Sapphire: 1.77
Salt: 1.54
Alcohol: 1.329
Emerald: 1.57
Polystyrene: 1.55

Note:If you make an object transparent, objects that are seen through it will be refracted only if their Visible In Refractions attribute is turned on.

This determines how great a proportion of the incoming light must be blocked for a shadow to appear. It requires that the shadow mode be set to shaded color or constant color. This is primarily of use for toon style shading.

By making the Specular Color brighter or dimmer, you can control the brightness of the specular reflections on an object.

Tip: To make a material look more plastic, use white for the specular color. To make a material look more metallic, make the specular color similar to the surface color. If there is more than one ramp index the specular color will vary based on the brightness of the highlight.

Specular Rolloff does not affect the reflections produced when you render using Ray Tracing.

Tip: to get a "wet" look (such as wet paint), make the edges more reflective.

(aka Studio special effect "Surface Width" - raytracing only)

The simulated thickness (in world space units) of transparent objects that are made from single surfaces (for example, a plane or face). Using Surface Width does not produce the same results as building a surface with actual thickness. However, the effect works well when the edges of the surface are not visible (for example, closed surfaces, or bounded shapes like a car windshield).

If this is set to 0 (the default) then no light shows through the object. If this is set to 1, all the light shows through.

The depth of penetration into an object at which translucence decays to nothing. When the parameter is 0, translucence does not decay with respect to the distance light travels through the object.

Note: If this material has specular highlights the transparency setting will not affect the highlights. So if you are trying to make an object disappear by animating the transparency attribute, you may also have to animate the specular highlight attributes. If there is more than one index in the ramp then the transparency value will vary with the facing angle.

This should be used for backwards compatability when rendering data from Studio - Maya users should use Absorbance instead.

The distance (in world units) camera rays can travel after passing through a transparent surface. Useful for effects like under water. If the Transp. Depth value is 0, camera rays can travel an infinite distance, and all objects behind the transparent surface are visible no matter how far away they are. For non-zero values, as a camera ray reaches the distance of the Transp. Depth value, its color becomes the surface color. Only objects near the transparent surface (less than the Transp. Depth value) are visible through the surface. Objects close to the surface are more visible (the surface is more transparent in those areas) and objects further away are less visible (the surface is less transparent in those areas). Objects beyond this depth are not visible at all (the surface is opaque in those areas).

This normal is used to check the reflection direction is not in the opposite direction of the normal of the visible triangle.