Application of 3D
Where and why is 3d used?
In The Architecture, Engineering, and Construction Industry for the 3D modelling of :
3D can be used in the form of CAD (Computer-aided design) to design, develop and optimise products, which can be goods used by end consumers or intermediate goods used in other products. CAD is used in the design of tools and machinery used in the making of components, and in the design of all types of buildings, from houses to hospitals and factories.
CAD is mainly used for detailed engineering of 3D models, but it is also used in the engineering process in the concept design and layout of products. It is carried on into strength and dynamic testing of assembling products.
CAD has become an important technology with benefits such as lower product development costs and a greatly shortened design cycle. CAD helps designers to lay out and develop work on screen, print it out and save it for editing so they casn save time on their drawings. The fact that ALL of this can be done from behind a computer moniter is an amazing benefit reducing costs massively.
This is a fully editable digital CAD production. Showing just how complex a drawing can become on 1 computer screen.
Rendering – Radiosity and Raytracing
The key benefits that radiosity offers over standard lighting are as follows: Improved Image Quality: Applying radiosity to 3ds max simply means that more precise photometric reproduction of the lighting in scenes you create. These images of more natural realism are achieved through effects such as indirect light, soft shadows and colour bleeding between surfaces.
Photometric units are systems for defining amounts of light energy
Here is a breakdown of different photometric units:
|
Symbol |
Term |
Unit |
Unit Definition |
| Q | Light quantity |
lumen-hour lumen-second
|
radiant energy as corrected for eye’s spectral response |
| F | Luminous flux | lumen | radiant energy flux as corrected for eye’s spectral response |
| I | Luminous intensity | candle candela candlepower |
one lumen per steradian one lumen per steradian one lumen per steradian |
| E | Illumination | foot-candle lux phot |
lumen/foot^2 lumen/meter^2 lumen/centimeter^2 |
| B | Luminance | candle/foot ^2 foot-Lambert = Lambert = stilb = nit = |
see unit def’s. above (1/pi) candles/foot^2 (1/pi) candles/centimeter^2 1 candle/centimeter^2 1 candle/meter^2 |
The main difference between Local and Global illumination is that in local illumination it is only direct lighting that is a variable. Local illumination algorithms only describe how individual surfaces reflect or transmit light. Global illumination gives an overall lighting solution through algorithms that takes account of all indirect lighting.
In mathematics, computing, linguistics, an algorithm is a list of well-defined instructions for a task that, given a beginning stage, will proceed through a well-defined series of successive states. The two types of Global illumination algorithms that are used in 3ds Max are radiosity and ray-tracing.
Ray tracing described simply is the process in which rays are traced from the camera through a pixel, to the geometry and then back to their light sources.
Radiosity offers a significant solution to ray tracing in the fact that radiosity is not camera dependent and that ray tracing is dependent on a camera.
| Lighting Algorithm | + | - |
|
Ray tracing |
Accurately renders direct illumination, shadows, specular reflections and transparency effects. Memory efficient. |
In the computing process this is expensive. The rendering process is greatly affected by the number of light sources. The process is view dependent so it must be repeated for each view. Ray tracing DOES NOT account for ‘diffuse interreflections’. |
|
Radiosity |
DOES calculate diffuse interreflections between surfaces. Gives view independent solutions for a fast display of arbitrary views. |
3D mesh requires more memory than the normal surfaces. The surface sampling algorithm can be more affected by imaging artifacts than ray-tracing. Does not account for specular reflections or transparency effects. |
Diffuse interreflection is a process where light reflected from an object strikes other objects in the surrounding area, illuminating them. Diffuse interreflection describes light reflected from objects which are not shiny or specular.
Artifacts are misrepresentations of structures such as a building or in medical use a tissue structure. These misrepresentations (artifacts) are caused by a reconstruction algorithm’s inability to represent the anatomy.
