reply to post by idunno12
To make my explanation somewhat easier to understand...in 3D computer graphics rendering,
the edges of objects need to be smoothed out and blended in with the background properly
so the edges don't look all jaggy or like stairsteps....this process is called anti-aliasing.
There are a number of techniques and ONE of them is called Inverse Squared Edge Blending
which means make each pixel on the edge (of a starship!) half as bright as
the previous edge pixel. This is done usually for 3 or 4 pixels from the solid
edge of a graphic object. Here is a numeric example of inverse square edge
smoothing where a solid outline or edge is at brightnesss 100%.
INVERSE SQUARED EXAMPLE:
Solid Edge Outline = 100% Brightness
Inverse Square 1st pixel = 50% Brightness
Inverse Square 2nd Pixel = 25% Brightness
Inverse Square 3rd pixel = 12.5% Brightness
Notice our each subsequent pixel is HALF the brightness of the previous pixel.
LINEAR EDGE RENDERING has a mathematically EVEN NUMBER of steps between each pixel.
Solid Edge Outline = 100% Brightness
Inverse Square 1st pixel = 90% Brightness
Inverse Square 2nd Pixel = 80% Brightness
Inverse Square 3rd pixel = 70% Brightness
Because of the way the human eye works which give preferences to the colours
closest to Bright GREEN...it means that inverse squared edges LOOK the smoothest
and least jaggy when blended with a photo background.
LINEAR edge blending is mathematically EASY AND FAST to do on a computer.
INVERSE SQUARED is HARD and SLOW to do...so some artists do a GOOD ENOUGH render
which tells the computer to SMART RENDER a 3D image by ONLY using the fancy blending
when an object edge is actually NOTICEABLE to a viewer. If the edge is too thin or too far away
the computer doesn't used the slow INVERSE SQUARED, it uses LINEAR edge blending to
SMART RENDERING can also refer to a 3D computer rendering technique called Ray-Tracing
which follows individual beams of light from a 3D rendered light source out to all surfaces and
edges as those beams of light bounce around in a scene. Those beams of light will brighten
or darken portions of an image or will create shadows based upon well-understood laws of physics.
Ray-Tracing makes objects look REAL by emulating how light bounces, reflects, refracts
and shimmers upon any metal, glass, wood, rubber or other surface. This of course takes
LOTS OF COMPUTER RENDERING TIME to do....ERGO...by SMART RENDERING,
we only follow beams of light that hit objects which are actually noticeable to the viewer.
This saves TIME but makes the resulting image LOOK MORE FAKE
than when FULL RAY-TRACE is turned ON.
When I talk about Fractally Non-Linear....I mean that the noise or colour shifting in a still photo
or video video should look random rather than have a distinct computer-like pattern to it.
That separates out real from fake.
Real clouds in the sky should move wobbly and stuttery with wispy edges and many curled
points AND NOT HAVE way-too-smooth or far-too-perfect movement and straight-lined edges.
The mathematics behind nature is a Fractal Equation...the mathematics behind 3D rendering
are binary powers of 2 which can be DETECTED by examining the brightness and colour of
individual pixels closest to each other in any still image or moving video.
Macro-Blocking is the resulting effect of making a video look like it was shot through a
mesh screen door. You start seeing the pattern of lines and squares caused by video
compression algorithms which keep throwing away image data to save computer
storage space until the final result becomes objectionable to the viewer. When that
point of seeing too many obvious blocky patterns in your video has been reached,
you'll KNOW whether too much compression has been applied.
HOWEVER, that blockiness artifact can be used to your advantage to DETECT images which
are real versus those that are FAKE by examining the SIZE and SPACING of the "Macro-Blocks"
which SHOULD BE somewhat random in "REAL" images. If the macroblocks are too uniform or
regular in size and placement or too smooth in colour, ESPECIALLY ON THE EDGES of an
on-screen object such as a starship, that means FAKERY to me! Edges should have some
randomness to them. If you ZOOM IN to an edge, you SHOULD SEE some randomization
to the placement, colours and brightness of nearby pixels.
If you see smudging or gooey-looking edges on ZOOM IN, that means artificial
blurring or blending of separate image layers. CAN YOU SAY FAKE!?
On smooth textures NOT near an edge, if you see banding or regular steps of colour
or brightness that could be caused by improper rendering of surfaces such as metal
or glass. The real stuff doesn't have colour banding and doesn't look artificially
smooth...there is ALWAYS SOME noise or random waviness in the surface
of a metal or glass. It's imperfect and thus REAL.3D fakery
is too smooth...and too perfect!
In my earlier post I said I saw motion that was too smooth....When a computer 3D artist
makes a round starship rotate, they usually set a single starting point and an end time point.
If they want the ship to rotate 3 times around within 6 seconds, they let the computer
figure out the amount of distance the ship must move as it spins for the number of frames
per second in a video. Modern television is approximately 30 frames per second...or
show 30 still photos one right after another PER SECOND to give the illusion of motion.
Mathematically if I want to rotate a ship 3 times in 6 seconds I let the computer calculate
that I must move 720 degrees of spin within 180 frames of video...ergo the result
is that I must render 4 degrees of spin for every frame that is rendered out.
HOWEVER...if i let the computer do that...the result is too perfect...nature has laws of
physics such as Inertia and Aerodynamics and Atmospheric Friction...To make my
rendering look REAL, the ship should SPIN somewhat irregularly, slightly speeding
up and slowing down in a semi-random manner. It should also wobble and jitter
slightly as if being BUFFETED by wind or other forces. By adding IMPERFECTION
to a 3D rendering, I can make it LOOK MORE REAL !!!! and THAT is why LucasFilm
and WETA and DIGITAL DOMAIN are the current MASTERS of 3D computer graphics!
They add the imperfect of the real world to an unreal 3D computer graphic which
when rendered out to video...looks REAL!!!!!
And regarding the other parts of my post....what makes you think I was joking?
Let's just say..... I have a bit more of an inside view on those topics......;-)
edit on 2011/5/28 by StargateSG7 because: Spelling and Grammar Fixes and additions