Radiosity & raytracing

What is Radiosity

There is two types of global illumination. There is ray tracing and there is radiosity. Radiosity is a rendering technology that simulates lighting effects onto an environment in ways that better simulate real light than standard program slighing could do. The quality of radiosity lighting can clearly be seen as superior to standard light when directly compared

Radiosity lighting vs Standard lighting

Whereas standard lighting uses scanline rendering which works row by row giving linear detail, radiosity works pixel by pixel allowing lighting and the shadows cast by the lighting to be more defined to where it touches, the effect of this can be described as an ink blot on wet paper. Radiosity also has indirect lighting where standard lighting creates nothing more than a silhouetted. However standard lighting i useful as it doesn’t need as much memory to render compared to radiosity.

Photometric units

Photometry is the science of measurement of light. photometric units is the measurement to measure light. such measurements are lumens and candelas. They are used in the same way as we use liters or pounds. Lumens is the general measurement but candelas are specifically used in measurement concerning narrow beams of light.

Local & global illumination.

Local illumination – or shaders when using 3d max terms describe how surfaces deal with lighting arrangements. The shaders determine if a surface will look like plastic, metal or wood, smooth or rough etc. In 3ds max if you use standard lighting, the light coming directly from the source is what is used to determine the shaders prediction of dealing with the light.

Global illumination – Shaders also work co-operatively with each other, a shader will detect if another object is blocking it and calculate accordingly what light it is still getting from the source and/or if the other object is emitting or reflecting light onto it. This process is called global illumination.

algorithm.

A algorithm is a definite list of well-defined mathematical instructions for completing a task.

Raytracing.

Ray tracing is a mathematic approach on 3D rendering. visualisations of programmed scenes are produced using a technique which follows rays from the eye point outward, rather than originating at the light sources” – wikipedia.

in a realistic simulation of lighting over other rendering methods due to the mathematical processing reflections and shadows have became a natural and thus easy effect to produce where as in other rendering techniques shadows and lighting are difficult to produce.

 

The shortfalls of ray tracing is it’s performance, it treats every ray separately when rendering, due to this and the strain of processing each, it takes a bit of power and a bit of patience when rendering a scene with ray tracing.  It also  starts the rendering process anew each time. Also when using ray tracing, rendering is not photo realistic, the shadows tend to be an exact silhouette of the shape rather than light being blocked by an object. Using ray tracing can give a rendered scene a cartoon look about it.

3D software programs

3D Graphics Software:

  • 3Ds Max – 3Ds max is used mainly used in the computer games industry to create the characters, objects and the scenes. Also used to create artwork from the rendered images.generate 2048 x 2048 resolution normal map from an 8.5 million triangle model in less than 1 minute.
  • AC3D – Used for games and simulations such as Xplane (flight sim)
  • Cinema 4D – Used for Cinema quality graphical special effects and CGI, lso used in other high end quality graphic projects including some games or at least cutscenes in the games. Also used to create artwork from rendered images.
  • Electric Image Animation System – Used in film and TV such as gangs of New York, Pirates Of The Carribean: Curse Of The Black Pearl and Starwars Episode One: The Phantom Menace for CGI and special effects.EIAS652.png
  • Form-Z – rendering images used by architects to create building concepts
  • Houdini – Used for film special effects, could have been used for more if not for is poor variety of intuitive tools
  • Lightwave 3D – used for art created from 3d rendered images, also used in films and games for special effects and CGI.

    Massive – Used in films, seems to be mostly for large scale battle simulations

  • Maya – Used in films for high quality CGI graphics such as in Pirates of the Caribbean which can fool the audience into thinking computer graphics to be the real macoy due to its excellent variety of tools.
  • Modo – used in games for creating models, and objects, films, CGI and special effects and as well as Computer generated art.
  • Silo – Silo is an advanced polygons sub division 3d modeler applications by nevercenter The developers made a conscious decision not to support nurbs modeling. Though it does have a strong and fast modeling tool set and a highly customizable interface.
  • SketchUp- Used by Architects to create high quality in depth concepts for buildings.
  • SoftImage|XSI – Used mainly in films, gaming and advertising industries for the production of 3D environments and scenes.
  • SolidThinking – Used to blend aesthetics and ergonomics with functionality in the form of cars, watches, bottles, jewels, mobile phones, product packaging, all of the designed objects that surround us.Used mainly by industries to design but also has a small user base in the computer graphics industry.

    Based on the NURBS system

  • TrueSpace – modeling/animation/rendering package. True space is capable of stunning graphic quality which makes it very useful for films and special effects.
  • Vue – Used in games for characters, vehicles and environmentwingman1.jpg
  • ZBrush – a digital sculpting tool that combines 3D/2.5D modelling, texturing and painting. This program uses a tablet (pen and board) to manual texture and sculpt the image making it a brilliant program for modeling objects and characters as you are given more artistic freedom.

  • Blender – freeware tool, not very good, used for modeling, animation, and rendering

3D software is the tool that is used to create 3D computer generated images. All of these programs could be used for creation of objects for films, special effects and games such as 300 and the Halo series but due to the tools in the programs it tends to be that in the cheaper programs (compared to their peers)  they seem to be strong in one area and weaker in the others because to keep te software relatively cheap focusing on one selling point in the market e.g.