This website has a good explanation of ray casting and how it was used in Wolfenstein 3D back in 1992: https://lodev.org/cgtutor/raycasting.html
VioIchigo
As mentioned in this slide, the procedure of ray casting is basically:
For every pixel:
Construct a ray from the eye
For every object in the scene:
Find intersection with the ray
Keep if closest
peterqiu1997
One simplifying assumption of ray tracing is that a surface facing a light will receive that light and not be blocked or in shadow. I'm guessing there's a limitation/additional challenge when modeling objects that bend/refract light or are slightly transparent?
tristanburke
@joannejqi Thanks for sharing that link! I thought it was clever how they worked around raytracing and light / shadow computation by simply coloring walls with a darker version of the texture to give the appearance of shadows!
nathanpetreaca
I think an interesting way of thinking about this, or at least it is how I first thought about it, is as the old emission theory. (https://en.wikipedia.org/wiki/Emission_theory_(vision)) Basically back then, people used to believe that the way they saw the world was through rays that emitted from their eyes. Kind of interesting how a debunked theory is used in technology. (https://c1.staticflickr.com/1/774/33266564316_bfc077540e_b.jpg)
https://publicdomainreview.org/collections/images-from-johann-zahns-oculus-artificialis-1685/
This website has a good explanation of ray casting and how it was used in Wolfenstein 3D back in 1992: https://lodev.org/cgtutor/raycasting.html
As mentioned in this slide, the procedure of ray casting is basically:
One simplifying assumption of ray tracing is that a surface facing a light will receive that light and not be blocked or in shadow. I'm guessing there's a limitation/additional challenge when modeling objects that bend/refract light or are slightly transparent?
@joannejqi Thanks for sharing that link! I thought it was clever how they worked around raytracing and light / shadow computation by simply coloring walls with a darker version of the texture to give the appearance of shadows!
I think an interesting way of thinking about this, or at least it is how I first thought about it, is as the old emission theory. (https://en.wikipedia.org/wiki/Emission_theory_(vision)) Basically back then, people used to believe that the way they saw the world was through rays that emitted from their eyes. Kind of interesting how a debunked theory is used in technology. (https://c1.staticflickr.com/1/774/33266564316_bfc077540e_b.jpg) https://publicdomainreview.org/collections/images-from-johann-zahns-oculus-artificialis-1685/