Graphics rendering pipeline Real-time computer graphics

1 graphics rendering pipeline

1.1 architecture
1.2 application stage
1.3 geometry stage

1.3.1 model , view transform
1.3.2 lighting
1.3.3 projection
1.3.4 clipping
1.3.5 screen mapping
1.3.6 rasterizer stage

graphics rendering pipeline

flight simulator screenshot

the graphics rendering pipeline known rendering pipeline, or simply, pipeline. foundation of real-time graphics. main function render two-dimensional image given virtual camera, three-dimensional objects (an object has width, length, , depth), light sources, lighting models, textures, , more.

architecture

the architecture of real-time rendering pipeline can divided 3 conceptual stages: application, geometry, , rasterization. structure core of real-time computer graphics applications.

application stage

the application stage driven application of image generation process results in final scene or frame of animation, creating database filled simple images. later on, these images can evolve clearer , larger images. application implemented in software, therefore giving developers total control on how change and/or improve performance. stage may contain collision detection, speed-up techniques, animations, force feedback, , other options. 1 of processes implemented collision detection. collision detection includes algorithms detect collision between 2 or more objects . after collision detected, response may generated , sent colliding objects. information can used force feedback device. other processes implemented in stage include: texture animation, animations via transforms, geometry morphing, or calculations not performed in other stages. @ end of application stage, important part of stage, geometry rendered fed next stage in rendering pipeline. these rendering primitives possibly end on output device, such points, lines, triangles, , more.

geometry stage

the geometry stage responsible majority of per-polygon operations or per-vertex operations, means stage computes needs drawn, how should drawn, , should drawn. polygon mesh created. stage done specialized hardware or graphics processing units. in cases, stage might defined 1 pipeline stage or several different stages, due different implementations of stage.

model , view transform

before final model shown on output device, model transformed onto several different spaces or coordinate systems. means when object being moved or manipulated, object s vertices being transformed. transformation general term 4 specific ways allow 1 manipulate shape or position of point, line, or shape.

lighting

in order give model more realistic appearance, 1 or more light sources equipped during transforming of model. however, stage cannot reached without completing 3-d scene being transformed view space. view space camera placed @ origin , aimed in way camera looking in direction of negative z-axis (where y-axis pointing upwards , x-axis pointing right).

projection

there 2 types of projection, orthographic (also called parallel) , perspective projection. orthographic projection used represent 3-d model in two-dimensional space. main characteristic of orthographic projection parallel lines remain parallel without distortion, after transformation. perspective projection concept if distance between camera , model increases, model appear smaller before. essentially, perspective projection way see things our eyes.

clipping

clipping process of removing primitives outside of view box in order continue on rasterizer stage. primitives outside of view box removed or clipped away. once primitives outside of view box removed, primitives still inside of view box drawn new triangles proceed on next stage.

screen mapping

the purpose of screen mapping find out coordinates of primitives determined on inside of view box during clipping stage.

rasterizer stage

once of necessary steps completed 2 previous stages, elements ready enter rasterizer stages. includes lines have been drawn , models have been transformed. during rasterizer stage, color applied , of elements stated turned pixels, or picture elements.