Monday, 4 February 2013

Comparing 3d Software Appications

3ds max
I have used 3 different 3d application software which all have different pro's and cons. I'am going to compare these from my experience. The first software is called 3DS Max by Autodesk. It is a software where you create models for a game for example. Its good for making characters and objects but very complicated to use. Since the UI is so complicated its hard for people to make what they want. This is good for rendering out still images and animations of your models.

Secondly is Sculptris which is a modelling software which follows the same physics of clay. It is made by Pixologic. This software is good for making characters using precise shapes.In this you can make very detailed models where you can mould the character yourself using very easy tools. The good thing about Sculptris that 3DS Max doesn't have is a easy to use interface. This is very important as Sculptris makes it very easy to make a basic model and you don't have to research into it loads so make a starter model.

Sketchup
Thirdly is SketchUp which is made by SketchUp . This is good for making environments and buildings. This is because it uses simple shapes which work well in making buildings. The main use of SketchUp is for architects to make buildings and see how they will plan out size-wise. Since its used for buildings, all its tools make it easier for you to make shapes and manipulate them to look how you want. The disadvantage is that you cant make models of a weapon for example but then you just use another software. When you have made your environment you can then export it into 3ds max and edit it or texture it since 3ds max has a more in depth features.

Autodesk Maya is a mix between Sculptris and 3ds max. The program mixes 3d modelling with animation mainly revolving around characters and people. There are alot of other programs out there which are similar to this. The two main programs that I have tried myself are Blender and 3D Canvas. Obviously Maya is the better choice because all around they're more features, less limits and a lot more professional. The main trade off is the price since Blender and 3d Canvas are free whereas Maya varies but can go up to 7000$.








Thursday, 17 January 2013

Graphics Pipeline and Shaders

The graphics pipeline is the process the GPU goes through to display 3d graphics in a game for example. There are various steps in this process which you don't see since it needs to complete them multiple times a second.

The first process is Vertex Processing also known as Pre-vertex lighting and shading. This is the process where is plots out all the vertices of the shapes in camera view. This is needed for a later stage because it needs to know where each model is to then display them in view.

3D Projection










The second process is clipping. This determines what can be "seen" and what can't. This varies when the game is being played as it changes once a second, maybe even more. To do this the GPU works out the co-ordinates of each of the vertex's and the distance between that and the camera. By doing this it can work out what is behind the other. Since it can't be seen at that precise moment it can hide it and not display it, saving processing power while doing this making the game run smoother overall.

Thirdly is projection transformation. This is a set of complicated calculations to again work out distance from camera. Basically this is achieved by dividing the X and Y co-eds by each of their Z co-ord. The end product of this is that no matter where the camera is, the object will keep its original size which is important for the proportion of them in the game.

Next is a process called rasterization. This is when it converts the image to a raster format. Raster images makes it so it works out each single pixel and doesn't resize it in real time. This makes it so it doesn't lag out the game and cause problems. This starts a whole other process called pixel pipeline.

Next is texturing and fragment shading. This is basically just texturing all the visible objects with the correct texture. This is done so you can tell what each item is and to make the game look better. Lighting is also done in this stage. The type of lighting changes depending how advanced the game is. The types are flat shading , gouraud shading and phong shading.

Finally the last process is display. This displays the view onto the screen for the player to see.It colours the final pixels so it can be displayed on a monitor.