Indigo Renderer is a 3D rendering

Rendering (computer graphics)

Rendering is the process of generating an image from a model , by means of computer programs. A scene file contains objects in a strictly defined language or data structure; it would contain geometry, viewpoint, texture, lighting, and shading information as a description of the virtual scene...

 software that uses unbiased rendering

Unbiased rendering

In computer graphics, unbiased rendering refers to a rendering technique that does not introduce any systematic error, or bias, into the radiance approximation. Because of this, they are often used to generate the reference image to which other rendering techniques are compared...

 technologies to create photo-realistic images. In doing so, Indigo uses equations that simulate the behaviour of light, with no approximations or guesses taken. By accurately simulating all the interactions of light, Indigo is capable of producing effects such as:

• Depth of field
  Depth of field
  In optics, particularly as it relates to film and photography, depth of field is the distance between the nearest and farthest objects in a scene that appear acceptably sharp in an image...
  
  , as when a camera is focused on one object and the background is blurred
• Spectral effects
  Diffraction
  Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665...
  
  , as when a beam of light goes through a prism and a rainbow of colours is produced
• Refraction
  Refraction
  Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
  
  , as when light enters a pool of water and the objects in the pool seem to be “bent”
• Reflections
  Reflection (physics)
  Reflection is the change in direction of a wavefront at an interface between two differentmedia so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves...
  
  , from subtle reflections on a polished concrete floor to the pure reflection of a silvered mirror
• Caustics
  Caustic (optics)
  In optics, a caustic or caustic network is the envelope of light rays reflected or refracted by a curved surface or object, or the projection of that envelope of rays on another surface. The caustic is a curve or surface to which each of the light rays is tangent, defining a boundary of an...
  
  , as in light that has been focused through a magnifying glass and has made a pattern of brightness on a surface

Indigo uses methods such as Metropolis light transport

Metropolis light transport

The Metropolis light transport is a SIGGRAPH 1997 paper by Eric Veach and Leonidas J. Guibas, describing an application of a variant of the Monte Carlo method called the Metropolis-Hastings algorithm to the rendering equation for generating images from detailed physical descriptions of three...

 (MLT), spectral light calculus, and virtual camera model. Scene data is stored in XML

XML

Extensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....

 or IGS format.

Indigo features Monte-Carlo path tracing

Path Tracing

Path tracing is a computer graphics rendering technique that attempts to simulate the physical behaviour of light as closely as possible. It is a generalisation of conventional ray tracing, tracing rays from the virtual camera through several bounces on or through objects...

, experimental support for bidirectional path tracing and MLT on top of bidirectional path tracing, distributed render capabilities, and progressive rendering (image gradually becomes less noisy as rendering progresses). Indigo also supports subsurface scattering

Subsurface scattering

Subsurface scattering is a mechanism of light transport in which light penetrates the surface of a translucent object, is scattered by interacting with the material, and exits the surface at a different point...

 and has its own image format (.igs).

Indigo was originally released as freeware until the 2.0 release, when it became a commercial product.

Integration with other software

Indigo may be integrated with the following 3D graphics applications:

• Blender
  Blender (software)
  Blender is a free and open-source 3D computer graphics software product used for creating animated films, visual effects, interactive 3D applications or video games. The current release version is 2.60, and was released on October 19, 2011...
  
  
• Autodesk 3ds Max
• Google Sketchup
• Cinema 4D
  Cinema 4D
  CINEMA 4D is a 3D modeling, animation and rendering application developed by MAXON Computer GmbH of Friedrichsdorf, Germany. It is capable of procedural and polygonal/subd modeling, animating, lighting, texturing, rendering, and common features found in 3d modelling applications.- Overview:The...
  
  
• Autodesk Maya
• Autodesk Revit

Truespace

TrueSpace

TrueSpace is a freeware 3D computer graphics and animation software developed by Caligari Corporation, bought-out by Microsoft. As of May 2009, it has been officially discontinued, but with some 'unofficial support' up to February 2010, at least.- History :The company was founded in 1985 by Roman...

is also supported through a user-developed exporter.