HA7 Task 6 – Constraints

Polygon Count and File Size

The polygon count is the number of polygon on a 3D model. A polygon is a face in 3D space with 3 edges and 3 vertices. A face can have up to 4 edges and verities before problems start to occur. If a Face has 5 vertices then it is classed as a "N-GON". A N-gon causes problems due to the computer not being able to calculate exactly how the lighting in the world effects the model and its textures. Artists must make sure to have all N-gons removed otherwise the development process will be slowed down dew to errors. 

The poly count must be kept to a minimum to stop the file being too large but at the same time it must not effect the overall look of the model. The process of cutting down a models poly count can be time consuming so planning ahead can stop large amounts of useless polygons from occurring thus saving time. Having a high amount of polygons also causes problems in the models animation and the rendering time will be increased dramatically. 

The file size of a model is one of the biggest issues when coming to export. The larger the file size the harsher it is on the users equipment. e.g. if a high poly model is used in a game and that game is used on a 4GB RAM PC then its likely the game could lag or even crash.

Rendering Time
Rendering is a massive time consumer and if a models file size is large then it can take hours just to render it once; this can slow down the production process quite a lot.

The two main render types are real time rendering and non real time rendering.

• Real time rendering is used in such things as games where the render is not high quality but is fast enough to keep the frame rate above 24 frames per second so the game play looks smooth.
• Non real time rendering is used for such things as animation, in this render technique each individual frame is rendered for the highest graphical quality. This render technique requires a much larger amount of time compared to real time rendering.