2011/render.txt

==== Render Methods ====

	Fractal
		  Used in one Lucas Arts game (pre-1990s), among others.
		A complex "repeating" formula is used per-pixel, taking advantage of the math
		instead of necessarily storing objects.

	Raster
		  Used by all generic video games, surface images are layered, sorted and
		rendered using horizontal or vertical line approaches.
		  Basic 3-D rendering involves sorting and clipping with depth first in line, using
		  depth as the divisor (improportionate) in scale.
		  Many systems come equiped with 2-D and/or 3-D graphics cards to reduce the need
		for low-level software rendering, freeing up CPU usage for other functions.

	Ray Tracing
		  Used by Pixar since "Cars," a virtual ray is sent out for each corresponding
		pixel, "hitting" a surface; reflections and refractions are common-place.  Using
		point-light sources, shadows are conceived.
		  Real-time ray tracing is achieved by using special hardware (i.e., Ray Processing
		  Unit) or by networking computers to form supercomputers for this slow method.
		  A "source point-obstruction" technique may've been used in DOOM 3 to create a
		similar effect using generic 3-D graphics cards.  One was even optimized for this.

	Radiosity
		  Used in the preprocessing of 3-D game light maps (per-pixel light intensity of
		surfaces), projections are cast from light sources and/or surfaces, minding
		distances.  Surface reflections may continue until the latest difference is within a
		margin of error.
		  Some ray tracing programs use a pseudo-radiosity algorithm for color "bleeding."

	Photon Mapping
		  One of the slowest approaches, yet potentially the most accurate, especially given
		the fact that photon mapping is capable of specular reflection (i.e., light
		reflecting off of mirrors), while ray tracing is not.
		  Virtual photons are cast (in rays), minding distance and certain physical
		characteristics, although colored elipsoids are used instead waves with wavelengths
		(that can interfere with each other).
		  Photon mapping software generally uses ray tracing for the final image.

		  If performed in real-time, minding all characterists of photons, including speed
		limits, photon mapping would produce the most realistic images ever created with
		computers.


==== After-effects ====

	Glare
		  Add marginal blurring, making sure samples have more than enough precision for
		overflow (16-bit integer to 32/64-bit floating-point); rescale only at the end.

	Dithering
		  Counter the error of end-sample precision limitations by introducing patterns.
		Use rotating tables via position or a surplus 'seed'.  Alternate even/odd for 2x2.


==== Quality ====

	Antialiasing
		  The basic method is to supersample, rendering at least 2x2 (4 per pixel),
		downsampling to the normal scale with interpolation.
		  Interpolation algorithms can be used to reduce the number of pixels needed
		to be rendered, with exception to edge pixels that cross more than once.

od28-6 notes
  The problem that arises in nixing the cone-based (ray-cast) method is the fact that less will
be added to the "visited" lines and polygons in the automap when vertically clipped.