Glossary

A

Abbe

Abbe is related to dispersion - the effect seen when a beam of light passes through a prism and is split up into different wavelengths of light. Abbe controls the amount of dispersion: the higher the Abbe number, the narrower the dispersion will be. If you set the Abbe number really high, the dispersion will disappear completely.

Aliasing

The process by which smooth curves and other lines become jagged because the resolution of the graphics device or the file is not high enough to represent a smooth curve. This problem can be solved with Anti-Aliasing.

Alpha Blending

The assignment of varying levels of translucency to graphical objects. This allows for the creation of things such as glass, fog, and ghosts. Alpha Blending can be accomplished by using alpha channels, or through other means.

Anisotropic Filtering

Anisotropic Filtering (AF) is a method of enhancing the image quality of textures and surfaces that are far away and steeply angled with respect to the point of view. Older techniques don’t take account of the angle that the surface is viewed from, which can result in aliasing or blurring textures. By reducing detail in one direction more than another, these effects can be reduced.

Anisotropy

The property of being directionally dependent, as opposed to isotropic, which means homogeneity in all directions. An anisotropic surface will change in appearance as it is rotated around its geometric normal, like with velvet. In Maxwell Render the Anisotropic material setting will create a material that is more reflective in one direction, and more diffuse in the perpendicular direction. In real life this is caused by polishing a surface in one dominant direction, making small grooves on the surface which run mostly in one direction.

Anti-Aliasing

This is the process that removes the aliasing effect. A filtering method is normally used in the process that removes the “jaggedness effect” produced by pixels. (See also Aliasing).

Aperture

An aperture is a hole or opening through which light is admitted. In photography, the aperture size of the lens can be adjusted to control the amount of light reaching the film. A diaphragm usually serves as an aperture stop and controls the aperture.

Attenuation distance

Attenuation is the reduction in amplitude and intensity of a signal. As light travels through a material, it loses energy. The Attenuation distance parameter in Maxwell Render allows you to specify how far light can move through an object before losing half its energy. For example, if you have a 2 cm thick glass window, and you set the Attenuation distance to 2 cm, the light shining through the glass on the other side will be half as bright.

B

BSDF

BSDF, or Bidirectional Scattering Distribution Function, is a set of mathematical functions that describe how light interacts with a material. These functions can describe opaque, transparent and translucent materials and their surface properties such as roughness, color etc.

Burn

An image is burned when its contrast is raised too much, and it results in the image containing uniform blobs of color, black, or white where there actually should be detail. In Maxwell Render, Burn is a tone-mapping parameter that controls how fast the image is over-exposed.

C

Camera Frustum

Generally, the field of view of the camera. The Camera Frustum in Maxwell Render is indicated by a yellow frame. Anything inside this frame will be rendered.

Channels

Rendering information can be stored separately in different images or channels, and this is usually done for compositing purposes. Maxwell Render can split the information obtained during the rendering process and produce independent Shadow channels, Alpha channels, Material Id channels, Object Id channels, Z-buffer channels, Motion Vector channels, Diffuse channels, and Reflection channel, as well as the complete composed image.

Clip map

A texture with completely black or completely white pixels only. It can be used in Maxwell Render as a Layer weight to determine which parts of a material should be made visible (white areas) or invisible (black areas).

D

Depth of Field

Depth of Field, or DOF, is the area in front and beyond the camera focal distance (the camera target) where the objects will appear in focus. The camera parameters that affect the DOF the most are the f-Stop and focal length settings. Other variables such as film width/ height and distance of the camera to the subject will also affect the DOF.

Diaphragm

In photography, a diaphragm is a thin opaque structure with an opening (aperture) at its center. The role of the diaphragm is to stop the passage of light, except for the light passing through the aperture. The diaphragm is placed in the light path of a lens or objective, and the size of the aperture regulates the amount of light that passes through the lens. Its diameter is controlled by the f-Stop parameter. The smaller the f-Stop value, the bigger the diaphragm opening, and viceversa.

Diffraction

This is an effect that happens when light goes through small holes, causing interference patterns. All lenses exhibit diffraction, especially when the camera lens is pointing straight at a strong light source such as the sun. Diffraction is also known as glare.

Diffuse

The reflection of light from an uneven or granular surface, resulting in an incoming light wave being reflected at a number of angles. Diffuse reflection is the opposite of specular reflection. It is the difference between glossy (specular) and matte (diffuse) paints.

Dispersion

The effect seen when a beam of light passes through a prism and is split up into different wavelengths of light.

E

Efficacy

Refers to the amount of light produced by a light source, usually measured in lumens. Efficacy specifies how many lumens are emitted per watt and thus how efficiently electricity is converted into visible light.

Emitter

In Maxwell Render, “emitter” refers to geometry that has an emitter material applied to it.

F

Focal length

The focal length of a lens refers to the distance between the lens itself and its focal point (where the light will be focused, usually where the film is). The focal length of a lens determines the field of view (FOV), or how much you see of your scene, and also the DOF. A small focal length lens (15-24mm) is said to be a wide-angle lens because it captures a lot of the scene (it has a wide FOV), and its DOF is wide (almost all the objects in the scene will be in focus). A large focal length lens (80-200mm) is said to be a telephoto lens as it acts like a binocular, “zooming” in to a particular area of your scene (it has a small FOV) and the DOF will be very narrow (only a small portion of your scene will be in focus).

FPS

An abbreviation for “frames per second”.

Fresnel Effect

The apparent increase/ decrease of a surface’s reflectance based on viewing angle. The Fresnel effect is dependent on the IOR of the material. The higher the IOR, the more reflective a material becomes at all angles. This means the Fresnel effect diminishes because the material becomes equally reflective at all angles. The effect has been named after the French physicist who described it.

f-Stop

An important notion in optics, f-Stop expresses the diameter of the diaphragm of the lens in terms of the effective focal length of the lens. f-Stop is the quantitative measure of lens speed in photography. The smaller the f-Stop, the bigger the diaphragm opening (aperture) of the lens is, allowing more light in and making the DOF narrower, meaning only a small area of the image will be in focus.

G

GMT

Refers to “Greenwich Mean Time”, generally used as a universal time zone.

I

IBL

Stands for Image Based Lighting. You can light your scene with a high dynamic range image (HDR, MXI, EXR). The image used should be in a longitude-latitude format to work correctly in Maxwell Render. It will be mapped to a virtual sphere that encompasses your scene. IBL images recreate lighting from real-world light sources to create realistic lighting environments.

Illuminance

Illuminance is specified in lux, which is defined as one lumen per square meter. It is a useful setting in Maxwell Render if you want to increase/ decrease the size of an emitter, and have it emit more or less light with the changed size of the emitter. For example, if an amount of light is emitted over a larger area, it will give the impression that the light is weaker.

IOR (complex/full)

IOR stands for “Index Of Refraction” and is a measure of how much the speed of light is reduced as it passes from a vacuum into a material. Complex or full IOR data are collected from precise measurements in laboratories and describe the optical properties of a material to the highest degree of accuracy. These materials are extremely realistic.

ISO

Film ISO, or film speed, is the measure of a photographic film’s sensitivity to light. The lower the ISO, the lower the film’s sensitivity, requiring a longer exposure, while a film with a high ISO needs only a short exposure to light.

L

Lambertian

Lambertian reflectance means that light falling on a surface is scattered in such a way that the apparent brightness of the surface is the same, regardless of the observer’s angle of view. In other words: the surface’s luminance is the same regardless of angle of view. Many rough surfaces, such as unfinished wood, exhibit Lambertian reflectance. In Maxwell Render, Lambertian behavior is seen when Roughness is set to 100.

Latitude

Describes a location north or south of the equator. Technically, it is an angular measurement in degrees ranging from 0 degrees at the equator, to 90 degrees at the poles. Latitude can be combined with longitude to give a precise position on the Earth’s surface.

Longitude

Describes a location east or west of a north-south line called the Prime Meridian. Longitude is given as an angular measurement ranging from 0 degrees at the Prime Meridian to +180 degrees eastward and -180 degrees westward. Longitude and latitude together can point to a specific location on the Earth’s surface.

Lumens

Lumens (lm) is the SI unit for luminous flux. It is a common way to specify how much light is emitted. Light manufacturers usually supply this data.

Luminous intensity

Luminous intensity is the power of light emitted in a certain direction, and it is specified in candela (cd).

M

Maxwell.exe

Previously known as MXCL, it is the core rendering application. Whether you launch your render via the plug-in from your 3D platform or from Studio, Maxwell.exe is the application that performs the actual rendering. Maxwell.exe also provides tools for image editing, Multilight controls, scripting features, etc.

Motion blur

The apparent streaking of rapidly moving objects in a still image or a sequence of images such as a movie. When a camera creates an image, that image does not represent a single instant of time, but a series of instants over a period of time. As objects in a scene move, an image of that scene must represent an integration of all positions of those objects, over the period of exposure determined by the shutter speed (or shutter angle in the case of an animation). In such an image, an object moving with respect to the camera will look blurred or smeared along the direction of the relative motion.

Multilight

Multilight™ is a special feature of Maxwell Render that allows the user to change intensities of individual lights in the scene during and after the rendering process. This feature is the first of its kind in a commercial render engine and it is extremely powerful allowing you to produce many different lighting combinations from just one render.

MXCL

Refers to the Maxwell render engine, which is command line controllable. Users can connect to MXCL via one of the supported plug-ins or through Studio.

MXED

Stands for “Maxwell Material Editor”. It is a standalone material editor within the Maxwell Render software, with powerful, layered, physical materials and a material browser.

MXI

Stands for “Maxwell Image”. It is Maxwell Render’s high dynamic image format which stores all the lighting calculations. This powerful image format allows for resume render and Multilight adjustments.

MXI/HDR (Maxwell Render parameter)

This option allows us to light the scene with a HDR or MXI map. In this box there is an option for selecting the type of lighting for the channels that are disabled. With this option you can, for example, insert a background into your image if you apply the map in background textured.

MXM

Stands for “Maxwell Material”. It is the Maxwell material format.

MXS

Stands for “Maxwell Scene”. It is the Maxwell Render scene format.

MXST

Stands for “Maxwell Studio”. It is an independent application within the core components of Maxwell Render. MXST allows users to import objects in different formats, create/ edit/ apply materials, and set up lights and textures. MXST can then send the scene to MXCL to be rendered. MXST is not a modelling application.

N

Not For Resale (NFR) Licenses

NFR licenses are issued to partners or resellers for non-commercial use.

O

Offset

An integer indicating the distance from the beginning of an object up until a given element or point, presumably within the same object.

OpenGL

OpenGL stands for Open Graphics Library and is a standard specification defining a cross-language, cross-platform API for writing applications that display 2D and 3D computer graphics. Graphics cards that take advantage of this library will speed up the display of 3D objects in the viewport.

P

Physical sky

Simulates the physical sky in an image for any time of day, any day of the year.

Polygon

A polygon is a closed plane which is bound by three or more line segments. A triangle polygon has three sides; a “Quad” had four sides and an “N-gon” can have more than four sides. Maxwell Render transforms all types of polygons into triangles when rendering.

R

RGB

Stands for “red, green, blue”. Red, green and blue are the 3 colors that are used by monitors to display images. They are called additive colors because the more of each RGB color is added, the brighter the resultant color. 100% of RGB will produce white.

S

Scattering

Lens Scattering, more commonly known as bloom, is caused by the imperfect focus of a lens, causing light scattering inside the lens before it reaches the film. This produces artifacts of fringes of light around very bright objects in an image, making is seem as if the image of the bright light bleeds beyond its natural borders.

SDK

Short for Software Development Kit, used by developers to create their own Maxwell Render plug-ins or applications.

Shutter

In photography, a shutter is a device that allows light to pass for a determined period of time to expose photographic film to the right amount of light to create an image. The shutterspeed is usually denoted in hundreds of a second, for example 1/100, which will keep the shutter open for one hundredth of a second.

Shutter angle

Film cameras use a rotating disc with an adjustable pie-shaped cut-out in it, which controls how long each frame is exposed. The width of the cut-out is called the shutter angle, and is expressed in degrees. The shutter angle controls the amount of motion blur in animations. Fully open (180 degrees) will yield the maximum amount of motion blur, while a very narrow setting (say, 15 degrees) will produce very subtle motion blur. In the Maxwell camera settings, the shutter angle you set automatically translates your usual ISO/ Shutter speed settings in combination with the shutter angle, so your animation exposure will match your still image exposure, while producing the proper amount of motion blur.

SimuLens

A collection of lens effects that mimic how a real optical device interacts with light. These effects include lens scattering, vignetting and diffraction. These effects are a post-process that can be applied to a render inside Maxwell Render.

Sky Dome

This is a virtual dome which encompasses your entire scene and can be used for uniform lighting. You can choose the color of the sky dome.

SL

Stands for Sampling Level. In Maxwell Render, this value controls the quality of the render. The higher the sampling level reached, the more accurate the image.

Specular

Specular reflection is the perfect, mirror-like reflection of light from a surface, in which light from a single incoming direction is reflected into a single outgoing reflection, for example with a mirror. Specular reflection is the opposite of diffuse reflection.

SSS

Stands for sub-surface scattering, an effect whereby light penetrates the surface of a translucent object, is scattered by interacting with the material under the surface, and exits the surface at a different point. Inside Maxwell Render, SSS is important for the realistic rendering of for example marble, skin and milk.

Studio

Previously known as Maxwell Studio or MXST. It is an independent application within the core components of Maxwell Render. Studio allows users to import objects in different formats, create/ edit/ apply materials, and set up lights and textures. Studio can then send the scene to Maxwell.exe to be rendered. Studio is not a modeling application and needs existing geometry to work with.

T

Turbidity

Turbidity is a cloudiness or haziness of water (or other fluids) caused by individual particles that are generally invisible to the naked eye.

U

Unbiased Rendering

The method of rendering which, contrary to biased rendering, does not use interpolation or guessing of the samples taken to render the image. Unbiased rendering avoids the typical interpolation and aliasing artifacts associated with biased rendering. This is the method of rendering used in Maxwell Render.

V

Vertex

In geometry, a vertex is a point formed by the intersection of the segments of the object: a vertex of a polygon is the point of intersection of two polygon edges. Plural: vertices.

Vignetting

In photography and optics, vignetting is a reduction in image brightness in the image periphery compared to the image centre. It can be controlled using Maxwell Render’s SimuLens parameters. Wide-angle lenses (with a focal length of around 24mm) will produce more vignetting compared to larger focal length lenses. After a certain focal length (around 80mm) the vignetting effect is no longer noticeable.

W

Watts

The Watt is the SI derived unit of power, equal to one joule per second. Watts specifies how much electricity a light source consumes.