User Guide

MAXWELL DIELECTRIC SHADER
Maxwell Dielectric Material
Type
Nd and Abbe presets for different materials.
Color
Defines the color of dielectric material.
Absorbance
Amount of light energy teminated by object. A value of 1 means
total absorbtion and it will be rendered black which means it
absorbs all the received light.
u and v Roughness
Disperses the scattered light energy randomly to achieve a more
rough surface for both (u,v) mapping directions.
Abbe number
Stands for chromatic aberration (dispersion). The dispersion is
measured by a standard parameter known as Abbe's
number where >55 are called as crowns (low dispersion) and
<50 are called as flints (high dispersion).
Nd number
This value corresponds to well-known Index of Refraction. For
empty space it's 1.0, for glasses ~1.5, for water 1.33 and so on...
Maps
Color Map
Not Available
Bump Map
Applies given bitmap as a height map for the bump effect. Since
the bump coefficient is positive, the bright pixels will be raised,
otherwise they will be collapsed. Use bumpmap coefficient to
multiply bumpiness.
Reflection Map
Not Available
Maxwell Render User Manual
10
Presets Materials
Amount of light energy
terminated by object
Controls Disperison
Index of Refraction
Surface Roughness
Not Available
Bump Map
Not Available
Coef. [-999.0,+999.0]
Maxwell Shaders
11
BEAUTY OF DISPERSION AND CAUSTICS
Dielectrics shader has benefits of refractive materials. Refractive materials are far
more time consuming due to heavy calculations like dispersion and caustics.
These materials scatter some amount of light back and let some amount of the
light through and emit some amount of the gathered light. The light energy
emitted through these materials disperses into spectrum colors parallel to abbe
value and combines together to form attractive caustic patterns.
The purpose of using dielectric shader is simulating glasses, diamonds, water,
transparent plastics etc. You may have semi transparent objects by altering
roughness. Absorbance and color control lightness and saturation respectively.
INTERACTIVE CONTENT Click here and drag mouse to test effects of roughness on dielectrics.
MAXWELL DIELECTRIC SHADER
CAUSTICS
DISPERSION
ABSORBANCE
Dispersion means chromatic aberration. The dispersion
is measured by a standard parameter known as Abbe's
number where >55 are called as crowns (low dispersion)
and <50 are called as flints (high dispersion). Light
disperse into visible spectrum shown below. Nd number
(refraction index) affects strength of dispersion directly.
To avoid this natural effect, set abbe to 150.
Caustics are patterns of light created by specular
reflections and refractions. As seen in the example,
caustics are also affected by the color and geometry of
the object. They will need more samples (more time) to
clear up. You can enable or disable rendering caustics
under Environment Settings in render panel.
When light is passing through, some of the energy is
being terminated by the object. This is called absorbance.
By default, absorbance set to 0.01 and when increased,
the thick parts of your object will become darker due to
light termination.