3D Animation notes FLIP

3D Animation • How 3D graphics work? o 2 ways: Keyframe animation (keyframing) and Motion capture o Keyframe animation is changing the shape, position, spacing, or timing of an object in successive frames with the major changes to the object being the key frames. It is more precise and slower than motion capture. o Motion capture (mocap) is where an actor is placed in a special suit containing sensors that record the motion of their body as they move. The data is interpreted and transformed into an animated character by the software. • What makes a picture 3D? o If the photo not only appears to have height and width, but has depth o It tells a more complicated story o Ex. A pyramid is 3D rather than a triangle since the pyramid takes five lines and six angles to tell the story of the pyramid, while the triangle only has three lines and three angles. • What are 3D graphics? o Making a picture move o Using a three-dimensional representation of geometric data that is stored in the computer for the purposes of rendering 2D images. • How to make it look real? o Three major steps: Creating a virtual 3D world, determining what part of the world will be shown on the screen and determining how every pixel on the screen will look so that the whole image appears as realistic as possible. o Putting pixels on a 2D screen and making it 3D o Different image parts go into making an object seem real: shapes, surface textures, lighting, perspective, depth of field and anti-aliasing.

• Lighting and perspective o 3D graphic animators need to always be thinking about the lighting on the object and how it moves around the room. One way of doing this is ray-tracing. This plots the path that light will be moving and how it sits on the image or what the animator is trying to create. Light helps to give the object the appearance of weight and solidity: shading and shadows. Shading is what makes the object or ball look round. The illusion of weight comes from the shadows. This helps lift the image of the page or a flat screen and seem more realistic. o Perspective makes everything look as though it will converge at a single point. Like two roads almost coming together and getting smaller as they reach this point. The same would go for trees. As you move along the road the father it gets the smaller the trees get and the closer they all get to meeting at that one point.• Depth of field o When looking at the trees from the perspective example, the trees that are further away from you will look more out of focus and not as clear as the ones closest. This also helps to focus your attention on to the main point of the scene creating the focal point.• Examples o Some great examples of 3D graphics and 3D animation are:  Avatar  Skyrim  Legend of Zelda  Assassins Creed  Nemo  Tangled  How to Train your Dragon• Making 3D graphics move o When watching an animation you get to see images called frames that will run at a rate of 24 frames per second. The retina in the eye can only retain images for a bit longer then 1/24th of a second which would cause the eye to blend the images together. This helps to make the images of movement and action that were standing still move once they are put together.

• Fluid Motion o The triangles and polygons of the wireframe, the texture of the surface, and the rays of light coming from various light sources and reflecting from multiple surfaces must all be calculated and assembled before the software begins to tell the computer how to paint the pixels on the screen. o A screen resolution of 1024 x 768 means there are 786,432 picture elements, or pixels, to be painted on the screen. o If there are 32 bits of color available, multiplying by 32 shows that 25,165,824 bits have to be dealt with to make a single image. o Moving at a rate of 60 frames per second demands that the computer handle 1,509,949,440 bits of information every second just to put the image onto the screen.• Transforms & Processors o A transform is a mathematical process used whenever we change the way we look at something. o An example of a transform is when the 3-D world created by a computer program has to be \"flattened\" into 2-D for display on a screen.• Graphic Boards o Most graphics boards have been translators, taking the fully developed image created by the computer's CPU and translating it into the electrical impulses required to drive the computer's monitor. o All of the processing for the image is done by the CPU -- along with all the processing for the sound, player input (for games) and the interrupts for the system. o It’s easy for even the fastest modern processors to become overworked and unable to serve the various requirements of the software in real time. o The graphics co-processor splits the work with the CPU so that the total multi- media experience can move at an acceptable speed. o The wireframe world is transformed from the three-dimensional mathematical world into a set of patterns that will display on a 2-D screen. o The transformed image is then covered with surfaces, or rendered, lit from some number of sources, and finally translated into the patterns that display on a monitor's screen. o Co-processors in the current generation of graphics display boards take the task of rendering away from the CPU after the wireframe has been created and transformed into a 2-D set of polygons.