unit 66 exercise 1

Applications of 3D

Applications of 3D can be seen in numerous mediums in different industries. These include films, games, TV series, Visual effects, Product design and architectural design among others. The list is endless. Most of these mediums utilise 3D software for modelling. They create 3D visualisations that can then be used in their respective sectors whether it be on a big movie blockbuster or in an indie game.

Displaying 3D Polygon Animations

Application programming interface: API is a set of routines, protocols and tools for building software applications. A good API makes it easier to create a software application by providing the necessary and simple to use building blocks. Examples of API are Direct3D and OpenGL

Direct3D: Direct3D is an API for Microsoft Windows and is used to render 3D graphics. It is used for applications where performance is paramount such as video games. Direct3D uses hardware acceleration. Direct3D uses techniques such as Z buffering, W buffering, Stencil buffering, Spatial Anti-Aliasing, etc.

Graphics Pipeline: GP or Rendering pipeline refers to process of creating a 2D representation of a 3D scene. When a 3D scene is created GP is the process of turning that 3D scene into what the computer displays to the user. Examples of GP are OpenGL and DirectX.

Rendering Techniques:

Radiosity: Radiosity is a method of rendering based on a detailed analysis of light reflections off diffuse surfaces. The images that result from a radiosity rendering are characterized by soft gradual shadows.

Ray Tracing: In computer graphics, ray tracing is a technique for generating an image by tracing the path of light through pixels in an image plane and simulating the effects of its encounters with virtual objects.

Rendering Engines: A major requirement for any image data application is the ability to display images. In most applications, this is achieved by reading pixel data from a filesystem and then mapping the pixel data to the 256 grey level available on most computer display monitors. Because these operations can require many thousands of operations and must be displayed rapidly to support the display of time-lapse movies, most image display software applications use a high-speed graphics CPU and dedicated hardware for image rendering and display.

Distributed Rendering Techniques: or Parallel rendering is the application of Parallel programming to the computational domain of computer graphics. Rendering process’ deal with four major parts: frame distribution, pixel distribution, object distribution and hybrid distribution. Parallel rendering refers to the delegation of rendering process among many different files. This is necessary as in such media as video games there are many different files that must be rendered and loaded all at once such as objects in the environment. The engine must render multiple different models at once or else there will be significant visual blemishes during play. The two main types of Parallel rendering are performance scaling, which allows for frames to be rendered more quickly, and data scaling, which allows for larger sets of data to be visualised.

Lighting: Lighting refers to the ways that the 3d scene is lit. Different lighting can effect mood and atmosphere and will also affect the shadows displayed in the scene. Two commons lighting methods are Radiosity and Ray Tracing.

Textures: Textures are 2D graphics that are applied to a 3D model or mesh. It usually utilises a Bitmap or Raster image. The textures are wrapped around the 3D mesh and when coupled with lighting can give the illusion of extra detail or depth. Textures are mapped onto every model in the game engine, this includes characters, environments, foliage, etc.

Distance Fog: Distance Fog is used in video games to simulate distance. Objects that are further away often appear hazier or more distorted. This effect aims to replicate the effect of light scattering as objects get further away. This effect causes objects to appear lower in contrast which makes object’s colours appear drowned out.

Shadow Mapping: Shadow Mapping is the process of the game engine calculating where shadows should be cast according to the geometry of the shapes and the lighting. Depending on what engine is being used there could be a variety of different parameters that are taken into account when calculating shadowing. This could be things such as shadow sharpness, darkness or intensity of shadows, dynamic shadows, etc. An explanation of the process by Wikipedia reads “Shadows are created by testing whether a pixel is visible from the light source, by comparing the pixel to a z-buffer or depth image of the light source's view, stored in the form of a texture.”

Vertex and Pixel Shaders: A Pixel Shader is a GPU (Graphic Processing Unit) component that can be programmed to operate on a per pixel basis and take care of stuff like lighting and bump mapping.

A Vertex Shader is also GPU component and is also programmed using a specific assembly-like language, like pixel shaders, but are oriented to the scene geometry and can do things like adding cartoony silhouette edges to objects, etc.

Level of Detail: The level of detail of a scene refers to how much data or memory is being used to render a scene. If the level of detail, which is usually tied to file type and how many polygons there are, is too high then the computer running the engine may not be able to render said scene and may crash. Similarly if the level of detail is too low then this use less memory, but will result in a crude looking model. Often video games have several different iterations of the same model that are used at different distances to scale the level of detail. For example a high detail model would be used up close, but a low detail model would be used from far away.

Geometric theory:

Vertices

 A point that describes the corners or intersections of a shape
Lines

A connection between two vertices
Curves

When a group of vertices are connected to change the direction of a line
Edge

The outside lines and cures of an object, area, or surface.
Polygons

A many-sided figures, with sides that are line segments.
Element

A specific part of a shape or object, elements together make a mesh.
Face

The surface of a shape.
Primitives

Any of a set of basic geometric shapes which may be generated in computer graphics.
Meshes, for example wireframe.

Represent a geometric object as a set of finite elements.
Coordinate geometry (two-dimensional, three-dimensional)

Plotting points, lines and curves on an x and y axis for 2D, to add another dimension, plot depth on the z axis.
Surfaces

A continuous set of points that has length and breadth but no thickness.

Constraints:

Polygon count

The polygon count refers to the number of polygons being rendered per frame. The higher the number of polygons in a model the more detailed it is, but it takes up more memory and is harder to run.

File size

The amount of data inside a file. The more detailed the model, the higher the file size. If a file is large it is going to be difficult to store and move between devices.

Rendering time

The time it takes to generate an image from a 2D or 3D model.

Mesh construction

Box modelling:

Box modelling is a technique used in 3D modelling where the user makes use of a primitive shape, such as a cube, and manipulates it to construct the basic outline of the final model. From this basic shape, the user will be able to further sculpt the mesh into the final model.

Extrusion modelling:

This technique of 3D modelling is also sometimes referred to as inflation modelling. The basic concept is to take a 2D mesh and sculpt it to match a reference image within the software. From this 2D sculpt, the user will then extrude the mesh into 3D with the help of a second reference image, sculpting the mesh to match. This method of modelling has proved common when sculpting faces and heads.

3D development software

Software

3Ds Max:

3Ds Max is a 3D computer development program used for making 3D animations, models, games and images. It is developed and produced by Autodesk media and entertainment.

Features:

·         Polygon, Spline and NURBS –based modelling

·         Advanced texturing toolset

·         Enhanced ShaderFX

·         OpenSubdiv support

·         Easy to use placement tools

Maya:

Similar to 3Ds Max, Maya is also a 3D computer graphics software. The program is used to create video games, animated films, TV series and visual effects. Maya was previously owned by Alias System’s corporation, however is now owned and produced by Autodesk media and entertainment.

Features:

·         Polygon and subdivision mesh modelling

·         3D Type

·         New sculpting toolset

·         Surface modelling

·         UV toolset

This will be the main software that we will be using as we have easy access to the software both in and out of college. The software is also the most helpful and efficient at creating the models we need.

Lightwave:

Lightwave is a 3D computer graphics tool developed by NewTek. It has been used to create a huge variety of mediums including that of films, TV series, motion graphics, digital matte painting, visual effects, video games, product design, architectural visualizations, virtual production, music videos, pre-visualizations and advertising.

Features:

·         Polygon and subdivision modelling

·         Surface modelling

·         Zbrush GOZ Support

·         Unity Game engine support

·         Autodesk Geometry Cache support

AutoCAD:

AutoCAD is a commercial software application for 2D and 3D computer-aided design (CAD. Hence Auto”CAD”) and drafting. AutoCAD is developed and produced by Autodesk media and entertainment. The software is used across a range of industries such as architects, graphic designers and project managers among others.

Features:

·         Coordination modelling

·         Reality computing

·         Surface curve extraction tool

Cinema 4D:

CINEMA 4D is a 3D modeling, animation and rendering application developed by MAXON Computer GmbH. The software is capable of procedural and polygonal/subdiv modelling, animating, lighting, texturing, rendering, and common features found in 3D modelling applications.

Features:

·         Flexible sculpting tools/Integrated sculpt system

·         Mirroring and masking

·         Mesh projection

File formats

.3ds: Native file format used by Autodesk’s 3Ds Max. It is a binary file format.

.mb: Similar to .3ds for 3Ds Max, .mb is the file format native to Autodesk’s Maya. This file format, believe it or not, is also binary.

.lwo: A .lwo file is the file extension used for a LightWave 3D Object File, developed by NewTek.

.c4d: A .c4d file is a Cinema 4D Model File developed by MAXON.

Plug-ins: In computing, a plug-in (or add-in / addin, plugin, extension or add-on / addon) is a software component that adds a specific feature to an existing software application. When an application supports plug-ins, it enables customization. The common examples are the plug-ins used in web browsers to add new features such as search-engines, virus scanners, or the ability to use a new file type such as a new video format.

Constraints

Polygon count: The polygon count refers to the number of polygons being rendered per frame. The higher the number of polygons in a model the more detailed it is, but it takes up more memory and is harder to run.

File size: The amount of data inside a file. The more detailed the model, the higher the file size. If a file is large it is going to be difficult to store and move between devices.

Rendering time: The time it takes to generate an image from a 2D or 3D model.