unit 66

Geometry

3D computer graphics employ the same principles found in 2D vector artwork, but use a further axis. When creating 2D vector artwork, the computer draws the image by plotting points on X and Y axes (creating coordinates) and joining these points with paths (lines). The subsequent shapes can be filled with colour and the lines stroked with colour and thickness if required.





Geometric Theory and Polygons
The basic object used in mesh modeling is a vertex, a point in three dimensional space. Two vertices connected by a straight line become an edge. Three vertices, connected to each other by three edges, define a triangle, which is the simplest polygon in Euclidean space. More complex polygons can be created out of multiple triangles, or as a single object with more than 3 vertices. Four sided polygons (generally referred to as quads) and triangles are the most common shapes used in polygonal modeling. A group of polygons, connected to each other by shared vertices, is generally referred to as an element. Each of the polygons making up an element is called a face.
In Euclidean geometry, any three non-collinear points determine a plane. For this reason, triangles always inhabit a single plane. This is not necessarily true of more complex polygons, however. The flat nature of triangles makes it simple to determine their surface normal, a three-dimensional vector perpendicular to the triangle's surface. Surface normals are useful for determining light transport in ray tracing.

A group of polygons which are connected by shared vertices is referred to as a mesh, often ferred to as a wireframe model.x










Primitives


The term geometric primitive in computer graphics and CAD systems is used in various senses, with the common meaning of the simplest (i.e. 'atomic' or irreducible) geometric objects that the system can handle (draw, store). Sometimes the subroutines that draw the corresponding objects are called "geometric primitives" as well. The most "primitive" primitives are point and straight line segment, which were all that early vector graphics systems had.










3D Development Software


Autodesk's 3DS Max is a professional piece of software for modeling animations, pictures and games. All these scenarios 3DS Max has made it easy for the user to create anything in the programme when you learn most of the basics. Even if you are new to using the programme you get free tutorials to use that pop up when you start the programme. This is useful even if you need a little refresher on how to use 3DS Max.




Autodesk's 3DS Max has a simple interface with many options you have to learn to create a 3D model, animation or game. You have four viewports to work from Top, Front, Left and 3D perspective view. You can navigate through the 3D view to see the whole model you are creating by using the mouse wheel on your mouse. You scroll to zoom, click and hold the wheel to move the camera and holding the alt key and holding the mouse wheel you rotate the camera around the perspective, or you can click and hold the transparent 3D cube and move it to move the camera around the model you are creating. You can even select to have only the any window you want by selecting the camera view you want (You will know by the yellow outline on the viewport) and clicking the "Maximize viewport window" button on the bottom right of the programme so you can get a view you like for modeling your design.




Once you have learned the basics of 3DS Max you have the tools to create anything you want from a simple box. You can even create a simple mesh constructed computer monitor by using a simple box and the tools you get with the programme. Even more advanced you can animate that computer monitor to turn on the spot without people having to own 3DS Max to view it. This process is called rendering and it creates images for one animation for when the monitor turns in an orbit and are converted into frames and animated in a format of the users decision, for example .avi (video), .JPEG (Image), etc...




Another technique that 3DS Max brings to modeling a product is by letting the user put a colour texture on what they have created and render that texture on the model to give it a good look for who they show the model to. The user will have to select a polygon that they want to colour or they can create a texture for the whole model.







The user will be able to save the file format for use in another programme but not from the "save as" menu. In the save as menu you can only save the file as a file for 3DS Max only. However when you go to the "Export" selection you will get a variety of file formats for the user to be able to work with this product in other programmes to use some tools that 3DS Max does not have. File formats like .DWG and .DXF are stored in the export options so you can edit your model in another AutoCAD programme.




However 3DS Max does take a big hit on your budget because this program costs a total of $3,675 (£2.451.51) which if you are a young enthusiast into 3D modelling you are not able to get this software. However there are other free programs on the internet that have some of the same compatabilities of 3DS Max but are avaible to the puplic free of charge. For example there is a 3D modelling program called Blender.











Blender is a 3D modelling software that opens the world of 3D modelling to everyone who is willing to give it a go. You are able to make models and animate them like the same way as 3DS Max does but with more freedom of tools that you do with the student edition of 3DS Max which you can get for free if you are using a student licence. Also if you have got a student version of 3DS Max and have a model you want to work on with no restrictions of tools you can use a certain save file type in 3DS Max that will allow you to cross model between program's that is very useful if you need to use some certain tools that you need for the model that is on one of the program's but not on the other. You can even go from Blender to 3DS Max so you can just keep swapping if that program does not have the tools that you need.




However there is another program compatible with these two programs that can make animating 3D models easier than using other 3D programs. Autodesk have a program called Maya and it focuses on character rigging which gives the character human joints and features. This will take practise to get the rigging exact on the character but it does pay off when you are there animating the model quicker than you would have been in 3DS Max or blender. However this also cost's money and is a blow to your budget because this also costs $3,675. So if you want both 3DS Max and Maya you will have to fork out more than $7,000 just for these industry programs. This is to costly for anyone who is just ambitious for 3D modelling and does not have the money for these programmes.






However another good program that is free to use is a 3D character rigger and animator from Daz. The company gives you the free software to do the same that maya does with its character rigging but with free software and they let you buy some pre-made and rigged characters to use in the program. However buying characters is optional you can still import characters and models into Daz's program and rig them yourself. These can be models from blender (which is also good with character rigging) and from 3DS Max (Which you can also do some character rigging on). This is probably one of the best free 3D riggers and animation programs you can get from a company because you do everything maya can but free of charge and you can also buy characters if you need a quick model in your scene that you are modelling in the program.







Types of shaders

There are 2 main types of shaders. Pixel shaders and vertex shaders. Pixel shaders work per pixel and are used for things like lighting and bump mapping. vertex shaders are oriented to the scene geometry of 3d space using the x, y and z coordinates and can add toon shading etc.

Pixel Shaders

Pixel shaders is a GPU shader that works on a per pixel basis. It applys textures and renders the image to the display per pixel. Pixel shaders add ambience to textures adding shadows, lighting and shapes. Using pixel shaders you can create a wide range of colour's throughout the environment by maniplulating lighting and shadows to create complex and realistic scenes.

This picture shows and example of the pixel shaders and how they have evolved. As you can see on the left there are shadows along with dim lights but it doesnt look very realistic whereas on the right is the newer version of shaders which allows the shadows and lighting to give a more realistic effect adding sharper edges and depth to the objects.









Vertex Shaders

Vertex shaders are run once for each vertex given to the graphics processor. The purpose is to transform each vertex's 3D position in virtual space to the 2D coordinate at which it appears on the screen (as well as a depth value for the Z-buffer). Vertex shaders can manipulate properties such as position, color and texture coordinate, but cannot create new vertices. The output of the vertex shader goes to the next stage in the pipeline, which is either a geometry shader if present, or the pixel shader and rasterizer otherwise. Vertex shaders can enable powerful control over the details of position, movement, lighting, and color in any scene involving 3D models.


pplications of 3D:




Models:




Models (like cars for example) are designed in programmes like "3DS MAX" because 3ds max has exclusive tools for users to easily create 3D models following simple steps of texturing, designing and rendering. If the user is not comfortable with the user they can customise the tools to their liking for comfy editing. It is good in businesses because it provides tools to draw from so they get the best results in the quickest of times to stay on deadline.












Product Design:




Product design is used in business is in the car industry. They create car alloys in a 3d program like 3ds max and use a CAM (Computer aided manufacture) technique to create the car alloy in the size the creator has told the machine to make it on the computer, and they tell it how many to create so it is also a way of mass production so the car manufacture can create a mass amount of car alloys for their customers.















Animation in film:




3D animation is used in hit blockbuster films like avatar and the matrix and it's programmes like 3DS Max that help achieve the professional standard of the modeling and animation. To achieve the standard they model the character in a spread out skeleton form and create an animation rig to give the character human like movements. The model + rig would be stored in it's own save file so whenever the company need to use the character or need to edit it, it will have its own save file so it does not get in the way of the work you are working on.















environments.

in the environment creation i used the scale tool on a empty landscape to rise the nods and such creating the mountains and paths this then lead to the creation of the games land this took a few hours in creation and the mountains would later be edited to create the caves and rooms.