What is Ray Tracing?

Techquickie ·Techquickie ·2019-05-06 · 962 words · ~4 min read
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0:00 thanks for watching techwiki click the subscribe button then enable
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0:07 unless you're sitting in complete darkness i'd like for you to do me a
0:10 favor take a look around the room you're in and notice a spot on the wall
0:15 then draw a line out of your eyes towards that spot and then follow it on
0:20 the angle that it would take towards the light source in your room
0:24 congratulations you've just done the same thing that
0:27 happens in ray tracing a graphics rendering technique that's been in the
0:31 tech news quite a bit lately on the heels of the launch of NVIDIA's touring
0:36 family of gpus which tout real time ray tracing as a way to get better looking
0:41 games but what exactly is ray tracing well to understand ray tracing it helps
0:46 to know why it's considered a step up from the traditional method by which
0:51 games draw or render scenes onto your screen
0:55 most games today use a technique called rasterization
0:58 where the game code will direct your GPU to draw a 3d scene with polygons
1:04 these two-dimensional shapes usually triangles make up most of the visual
1:08 elements that you see after the scene is drawn it gets
1:12 translated or rasterized into individual
1:15 pixels which are then processed by a shader which affects colors textures and
1:21 lighting effects on a per pixel basis to give you a fully rendered frame then you
1:26 do this 30 or 60 times per second depending who you ask and you've got
1:30 yourself a fully responsive video game to enjoy
1:33 but while rasterization has served us well for a long time trying to
1:38 approximate an image by translating 3d shapes onto a 2d screen and then using
1:44 shaders to estimate what the lighting should be has inherent limitations
1:49 because this method of rendering has a hard time tracking exactly how light
1:54 should travel and bounce within a certain scene
1:58 ray tracing does a much better job of this and you've actually probably been
2:02 enjoying it without knowing it for years if you've gone to any recent movie that
2:06 features cgi effects what made this possible in movies though
2:11 is that big budget productions have the luxury of lots of money to render those
2:16 effects on large server farms a process
2:19 that can take months and uses much more computationally intensive techniques
2:24 with many bounces for each photons and a
2:27 huge number of light rays coming from each source just check out this still
2:31 life created with a ray tracing program you would be forgiven for thinking that
2:36 it is a real photograph at first glance okay so ray tracing is amazing right
2:40 let's use it for everything well not quite the downside of ray
2:44 tracing is the computational cost and
2:47 the average 20 something gaming at home doesn't have millions of dollars or a
2:52 rendering server and on top of that games have to be rendered at at least 25
2:57 or so frames per second not one frame per day as has been the case in some
3:02 pixar films so instead of tracking
3:05 however many trillions of rays that come from each light source consumer grade
3:10 ray tracing lessens the computational load by instead tracing a path from a
3:15 virtual camera that represents the user's eyes through a single pixel then
3:21 to whatever object is behind that pixel and finally back to the inseam light
3:25 source for added realism if whatever that ray
3:29 bounced off of absorbs or diffuses the light like a rough rock or a tree trunk
3:34 the ray tracing algorithm can take these additional rays of light into account as
3:38 well so that any refraction effects or shadows are displayed accurately
3:43 and because lighting is such an important aspect of achieving a
3:47 convincing 3d render once this process is completed for each pixel your GPU can
3:52 throw out some insanely detailed images like any new GPU feature though it'll
3:57 come down to industry support now on the hardware side given AMD's professional
4:02 grade ray tracing solutions we'll probably see both teams add support in
4:06 the future as for the game developers
4:09 well there's no guarantee so all we can really do is hope that you won't end up
4:14 paying a premium for some feature that you'll never actually use
4:18 like that time that you were planning to get ripped on your new wii fit
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4:50 supports multiple vpn protocols and encryption levels allowing you to dial
4:54 in the exact level of protection you need they've got apps for Windows mac
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5:05 check them out at the link below so thanks for watching guys like dislike
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