2022-11-11 01:08:11 +00:00
|
|
|
= Light transport =
|
|
|
|
|
|
|
|
|
|
== Radiometry recap ==
|
|
|
|
|
|
|
|
|
|
What is radiant flux?
|
|
|
|
|
* total amount of energy passing through a surface (measured per second)
|
|
|
|
|
* Radiant flux in Watts or Joules/second
|
|
|
|
|
|
2022-11-11 01:15:01 +00:00
|
|
|
=== Why do we not use radiant flux? ===
|
2022-11-11 01:08:11 +00:00
|
|
|
|
|
|
|
|
* When we emasure a high flux val, we dont know if lots of energy through a
|
|
|
|
|
small surface, or a little energy through a huge surface
|
|
|
|
|
* TLDR its to ambiguous
|
2022-11-11 01:15:01 +00:00
|
|
|
|
|
|
|
|
New unit irradiance
|
|
|
|
|
* Flux per unit area
|
|
|
|
|
* IE Watt/m^2
|
|
|
|
|
|
|
|
|
|
=== Why do we not use irradiance? ===
|
|
|
|
|
|
|
|
|
|
We know the surface, but we still need an angle
|
|
|
|
|
* Could be lost of energy in a huge angle
|
|
|
|
|
* little energy in a small angle
|
|
|
|
|
|
|
|
|
|
New unit Radiance
|
|
|
|
|
* Flux per unit area angle
|
|
|
|
|
* W / (m^2 * radians)
|
|
|
|
|
|
|
|
|
|
== Basic question ==
|
|
|
|
|
|
|
|
|
|
How do we calculate how much light exits a surface point in a given direction
|
|
|
|
|
|
|
|
|
|
[[maxwell_equations|Maxwell equations]]!
|
|
|
|
|
|
