The GeForce3 videocards that will be released are all running steadily at a
200 MHz core speed. The first series will all be launched with 64MB memory based
upon 3.8ns memory. The nominal and default speed for this memory will be a clock
frequency of 460 MHz (230 MHz DDR). The GeForce3 has four pixel-pipelines,
therefore the maximum Pixel fillrate will be 800 MPixels/sec. That's the same as
the geForce2 Ultra, still this videocard will be faster due to it's ‘lightspeed
memory architecture’ which I will explain later.
Let's take a brief look on how the GeForce3 builds a scene.
nfiniteFX Vertex processor - Before the 3D chip will
start to calculate 3D images the CPU has to calculate a number of items for a
game like Artificial intelligence, statistics, 3D object positioning etc. The
CPU also builds all 3D Objects from tiny triangles. As soon as everything is
calculated by the CPU it will send the coordinates and corner/angular point's to
the Transformation and Lightning (T&L) engine which will calculate how to
display the 3D information on your 2D monitor. When you look at the diagram
above you'll probably notice the blue section with nfiniteFX Vertex processor.
With the help of DirectX8 a game developer can use his own effects in that stage
compared to a normally standardized T&L phase.
What is a Vertex Shader? - Before the advent of NVIDIA's
nfiniteFX engine, realistic characters and environments were beyond the reach of
graphics processors. Now programmable Vertex Shaders enable an unlimited palette
of visual effects that can be rendered in real time. But what are programmable
Vertex Shaders, and how do they work? To answer this we have to start with the
basics. In order to understand Vertex Shaders, it's important to know what a
vertex is in relation to a scene. Objects in a 3D scene are typically described
using triangles, which in turn are defined by their vertices. A vertex shader is
a graphics processing function used to add special effects to objects in a 3D
environment by performing mathematical operations on the objects' vertex data.
Each vertex can be defined by many different variables. For instance, a vertex
is always defined by its location in a 3D environment using the x-, y-, and
z-coordinates. Vertices may also be defined by colors, textures, and lighting
characteristics. Vertex Shaders don't actually change the type of data; they
simply change the values of the data, so that a vertex emerges with a different
color, different textures, or a different position in space. Before the
introduction of the GeForce3, vertex shading effects were so computationally
complex that they could only be processed offline using server farms. Now,
developers can use Vertex Shaders to breathe life and personality into
characters and environments, such as fog that dips into a valley and curls over
a hill; or true-to-life facial animation such as dimples or wrinkles that appear
when a character smiles
Examples of vertex shading effects include: matrix palette
skinning, which allows programmers to create realistic character animation with
up to 32 "bones" per joint, allowing them to move and flex convincingly;
deformation of surfaces, which gives developers the power to create realistic
surfaces such as waves and water that ripples; and vertex morphing, which is
used to morph triangle meshes from one shape to another, providing smooth
skeletal animation. These are just a few of the virtually infinite number of
effects developers can create using Vertex Shaders. By customizing skinning and
motion, developers can create life-like personalities for characters and scenes,
thereby intensifying the graphics experience
