The Raytrace Basic Parameters rollout for a Raytrace material controls the material's shading, color components, reflectivity or refractivity, and bumps.
The basic parameters in this rollout are similar to the basic parameters for standard materials, but the color components of a Raytrace material behave differently.
As with standard materials, you can use maps for Raytrace color components and various other parameters. The small buttons to the right of the color swatches and parameters take you to the Material/Map Browser, where you select a map of corresponding type. These are shortcuts that also have corresponding buttons in the Maps rollout. If you have assigned a map to one of these colors, the button displays the letter M. An uppercase M means that the corresponding map is assigned and active. A lowercase m means that the map is assigned and inactive (turned off).
If you have a 2-sided, reflective and refractive object, and you use the raytrace map rather than the material, the raytracer runs until it hits the maximum recursion level. This can be time-consuming.
With pixels, wires maintains the same apparent thickness regardless of the scale of the geometry or how near or far the object is positioned. With units, the wires appear thinner at a distance and thicker at close range, as if they were modeled in the geometry.
Click the map button to assign an Ambient Color map. This button is a shortcut: You can also assign an Ambient map on the Maps rollout.
Click the map button to assign a Diffuse Color map. This button is a shortcut: You can also assign a Diffuse Color map on the Maps rollout.
If raytracing is off (on the Raytracer Controls rollout), the object still reflects the environment, but ignores other objects in the scene. The environment can be the background color, the environment map, or the map in the Raytrace material's Environment component.
Click the map button to assign a Reflection map. This button is a shortcut: You can also assign a Reflection map on the Maps rollout.
Click the map button to assign a Self-Illumination map. This button is a shortcut: You can also assign a Self-Illumination map on the Maps rollout.
If raytracing is turned off (in the Raytracer Controls rollout), the object still refracts the environment map, but ignores other objects in the scene.
Click the map button to assign a Filter Color map. This button is a shortcut: You can also assign a Filter Color (Transparency) map on the Maps rollout.
Click the map button to assign a Refraction map. This button is a shortcut: You can also assign a Refraction map on the Maps rollout.
Common IORs (assuming the camera is in air or a vacuum) are:
Material | IOR Value |
---|---|
Vacuum | 1.0 (exactly) |
Air | 1.0003 |
Water | 1.333 |
Glass | 1.5 to 1.7 |
Diamond | 2.418 |
In the physical world, the IOR results from the relative speeds of light through the transparent material and the medium the eye or the camera is in. Typically this is related to the object's density, and the higher the IOR, the denser the object.
You can also use a map to control the IOR. IOR maps always interpolate between 1.0 (the IOR of air) and the setting in the IOR parameter. For example, if the IOR is set to 3.55 and you use a black-and-white Noise map to control IOR, the IORs rendered on the object will be set to values between 1.0 and 3.55. The object will appear denser than air. If, on the other hand, your IOR is set to 0.5, then the same map values will render between 0.5 and 1.0, as if the camera were under water and the object was less dense than the water.
Here are some more IOR values for various materials:
Material | IOR Value |
---|---|
Carbon Dioxide, Liquid | 1.200 |
Ice | 1.309 |
Acetone | 1.360 |
Ethyl Alcohol | 1.360 |
Sugar Solution 30% | 1.380 |
Alcohol | 1.329 |
Flourite | 1.434 |
Quartz, Fused | 1.460 |
Calspar2 | 1.486 |
Sugar Solution 80% | 1.490 |
Glass | 1.500 |
Glass, Zinc Crown | 1.517 |
Glass, Crown | 1.520 |
Sodium Chloride | 1.530 |
Sodium Chloride (Salt) 1 | 1.544 |
Polystyrene | 1.550 |
Quartz 2 | 1.553 |
Emerald | 1.570 |
Glass, Light Flint | 1.575 |
Lapis Lazuli | 1.610 |
Topaz | 1.610 |
Carbon Bisulfide | 1.630 |
Quartz 1 | 1.644 |
Sodium Chloride (Salt) 2 | 1.644 |
Glass, Heavy Flint | 1.650 |
Methylene Iodide | 1.740 |
Ruby | 1.770 |
Sapphire | 1.770 |
Glass, Heaviest Flint | 1.890 |
Crystal | 2.000 |
Diamond | 2.418 |
Chromium Oxide | 2.705 |
Copper Oxide | 2.705 |
Amorphous Selenium | 2.920 |
Iodine Crystal | 3.340 |
The controls in this group affect the appearance of specular highlights. Specular highlights simulate the surface of the raytraced object reflecting the lights in the scene. Changing the color or intensity of lights in the scene can change the appearance of specular highlights.
As in standard materials, as you adjust the values in this group the highlight curve at the right changes to give you an idea of the effect. The material preview in the sample slot also updates.
Click the color swatch to display the Color Selector and change the highlight color.
Click the map button to assign a Specular Color map. This button is a shortcut: You can also assign a Specular Color map on the Maps rollout.
The remaining controls in the Specular Highlight group depend on the active shader, as shown next to “Shading:” at the top of this rollout. These highlight controls are the same as for the Standard material shaders.
These are the highlight controls available to Raytrace materials:
This map overrides the scene-wide environment for both reflection and refraction. To override for refraction alone, see the Transparency Environment control in the Extended Parameters rollout.
Use the checkbox to turn this map on or off.
The lock button to the right locks the Environment map to the Transparency Environment map (found on the Extended Parameters rollout). When on, the Transparency Environment map controls are disabled, and a map applied to the Raytrace Environment applies to the Transparency Environment as well. When off, the Transparency Environment map controls are enabled, and the Transparency Environment can have a different map assigned to it. Default=on.
Changing this button’s setting here also changes it on the Extended Parameters rollout and the Maps rollout.
Use the spinner to change the bump Amount. Use the checkbox to toggle the map.