How is path tracing different from ray tracing tho?
motoole2
@tracychen I often conflate the two terms myself (and may have done so in class), but there is a distinction between the two. The key difference between ray tracing and path tracing is the types of paths integrated through the rendering equation. Path tracing involves computing the contribution of all possible light paths, and ray tracing involves computing the contribution from a subset of light paths.
Ray tracing usually refers to shooting out a ray from a camera, reflecting/refracting the ray every time it intersects a specular point (e.g., a mirror, or a glass object), and continuing this process until it reaches a diffuse (non-specular) point. The point is then connected to light sources to compute the surface shading value.
Path tracing does this and more. Path tracing also calculates the contribution of light paths bouncing between multiple diffuse (non-specular) points within the environment. So it provides a more realistic representation of light transport in a scene.
How is path tracing different from ray tracing tho?
@tracychen I often conflate the two terms myself (and may have done so in class), but there is a distinction between the two. The key difference between ray tracing and path tracing is the types of paths integrated through the rendering equation. Path tracing involves computing the contribution of all possible light paths, and ray tracing involves computing the contribution from a subset of light paths.
Ray tracing usually refers to shooting out a ray from a camera, reflecting/refracting the ray every time it intersects a specular point (e.g., a mirror, or a glass object), and continuing this process until it reaches a diffuse (non-specular) point. The point is then connected to light sources to compute the surface shading value.
Path tracing does this and more. Path tracing also calculates the contribution of light paths bouncing between multiple diffuse (non-specular) points within the environment. So it provides a more realistic representation of light transport in a scene.
Specifically, ray tracing produces images like this, which captures reflections/refractions. Path tracing produces images like this, which also includes diffuse inter-reflections from light bouncing between the walls.