Volume Rendering Basic Theory

• Volume Rendering Basic Theory
  • properties of volumes
  • light propagation in volumes
  • discrete methods

properties of volumes

• what are volumes

  Volumes, are collections of particles, ranging from atoms and molecules to any particle size.

• collision probability the chance of a photon collision
  • probability density of collision per unit distance defined by a coefficient σ(x), which is the probability density of collision per unit distance traveled inside the volume. The physical unit of a collision coefficient is inverse length.
  • mean free path the average distance traveled between collisions.

light propagation in volumes

• radiative transformation equation(RTE)

  what happens to a radiance beam as it travels forward

  • absorption
  • out-scattering
  • emission
  • in-scattering
  • RTE

• Volume Rendering Equation(VRE)

  describes the radiance in terms of where it comes from

discrete methods

积分转换成离散求和，沿一个方向ray marching来累积。 这部分待推导