Week 6 - The rendering equation Flashcards
What is the rendering equation?
A mathematical abstraction of how light interacts with materials in a 3 dimensional space.
It is trying to model what the steady state colour of a particular point was, as seen by the viewpoint
What is the bit on the far left of the rendering equation? (on the left of =)
The spectral radiance arriving along direction omega O from point x
It represents the light you can see in direction o from point x
What concept from radiometry takes into account the wavelength and time?
spectral radiance
What is the first equation on the right of = in the rendering equation (before the integral sign)?
Emitted light coming from the point X, going along the vector Omega o towards the light point. This for if a point is a light source, i.e. it emits light
What does the integral mean in the rendering equation?
for hemisphere big omega, we’re going to add up all the contributions for the incoming omega i vectors, when evaluating this part of the equation
What is the Li term in the integral of the rendering equation?
The light arriving from elsewhere, that’s i. for incident of incoming
What is the first f part of the integral in the rendering equation?
The BRDF (bi-directional reflectance distribution function
What is the final part of the integral in the rendering equation?
The dot product of the inverse of omega i and the surface normal at point x.
This basically means if the light hits the surface at 90 degrees (tangent to the normal) it will have full effect, if it’s just grazing along the surface it will have very little effect.
Remember the dot product of two vectors is the cosine of the angle between them
What law does the final part of the integral of the rendering equation implement?
Lambert’s cosine Law
What type of equation is the rendering equation?
a Fredholm equation of the 2nd kind