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Maybe I'm wrong, but the terminology isnt that clear. Path tracing is a sub field of Ray tracing - Ray tracing refers to the camera into scene Ray generation. W

Maybe I'm wrong, but the terminology isnt that clear. Path tracing is a sub field of Ray tracing - Ray tracing refers to the camera into scene Ray generation. What he describes as raytracing sounds like the whitted recursive algorithm.

berkut 8y ago
The terminology's always been a bit vague: technically "Ray casting" is a more accurate way to describe one ray being sent out and intersected with something (i.e. from camera/eye into the scene). The "tracing" part used to imply Whitted, but then things like PRMan introduced "raytraced shadows" as an alternative to shadow maps, and it took on a dual-use meaning...
slavik81 8y ago
You do sometimes see people using the term narrowly, but often the entire category of renderers is referred to as ray tracers. (Which I think makes sense, because they're all based on tracing the paths of rays.) A notable example of that usage: > When somebody says "ray tracing" it could mean many things. What I am going to describe is technically a path tracer ~ "Ray Tracing in a Weekend" by Peter Shirley
pasta 8y ago
Ray casting = where does a ray intersect an object Ray tracing = ray casting from the camera and where an object intersects trace rays (with ray casting) to light sources and reflective materials (Turner Whitted). Path tracing = ray tracing but when you hit an object start ray casting from that point as bounce and gather all energy so you can send it back to the camera (James Kajiya ?). So to me path tracing is just a method (extension) of ray tracing.
- atq2119 8y ago
  ... and yet, in the DXR API, the TraceRay function does what you're calling ray casting here, i.e. it figures out the intersection of a single ray with the scene (and calls a shader associated to the hit material, to somewhat simplify it; in any case, TraceRay doesn't trace multiple rays). The terminology just isn't 100% consistent.

berkut 8y ago

The terminology's always been a bit vague: technically "Ray casting" is a more accurate way to describe one ray being sent out and intersected with something (i.e. from camera/eye into the scene). The "tracing" part used to imply Whitted, but then things like PRMan introduced "raytraced shadows" as an alternative to shadow maps, and it took on a dual-use meaning...

slavik81 8y ago

You do sometimes see people using the term narrowly, but often the entire category of renderers is referred to as ray tracers. (Which I think makes sense, because they're all based on tracing the paths of rays.) A notable example of that usage: > When somebody says "ray tracing" it could mean many things. What I am going to describe is technically a path tracer ~ "Ray Tracing in a Weekend" by Peter Shirley

pasta 8y ago

Ray casting = where does a ray intersect an object Ray tracing = ray casting from the camera and where an object intersects trace rays (with ray casting) to light sources and reflective materials (Turner Whitted). Path tracing = ray tracing but when you hit an object start ray casting from that point as bounce and gather all energy so you can send it back to the camera (James Kajiya ?). So to me path tracing is just a method (extension) of ray tracing.

atq2119 8y ago
... and yet, in the DXR API, the TraceRay function does what you're calling ray casting here, i.e. it figures out the intersection of a single ray with the scene (and calls a shader associated to the hit material, to somewhat simplify it; in any case, TraceRay doesn't trace multiple rays). The terminology just isn't 100% consistent.