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Image Formation. (Forward) Ray Tracing. (Backward) Ray Tracing. When the ray hits an object, a secondary ray, ("shadow" ray), is shot towards the light sources. Shadow Ray. Determine if that point on the object is in a shadow.
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Image Formation (Forward) Ray Tracing (Backward) Ray Tracing
When the ray hits an object, a secondary ray, ("shadow" ray), is shot towards the light sources Shadow Ray Determine if that point on the object is in a shadow. If this shadow ray hits another object before it hits a light source, then the first intersection point is in the shadow of the second object. Only apply the ambient term for that light source at the point of intersection
When a ray hits an object, a reflected ray is generated and tested against all of the objects in the scene. If the reflected ray hits an object then a local illumination model is applied at the point of intersection and the result is carried back to the first intersection point. Reflected Ray
If the intersected object is transparent, then a transmitted ray is generated and tested against all the objects in the scene. If the transmitted ray hits an object then a local illumination model is applied at the point of intersection and the result is carried back to the first intersection point. Transmitted Ray
Ray Tree • The reflective and/or transmitted rays are continually generated until the ray leaves the scene without hitting any object or a preset recursion level has been reached. This then generates a ray tree. DEMO
Fast Ray-AABB Overlap Tests with Plucker Coordinates Mahovsky and Wyvill [2003]
Standard Method Ray (O,D) y=y1 y=y0 Similarly,
t 0 t 0
Ray vs. Directed Line Here, it is looking from the head of ray CW CCW
(MMM: minus,minus,minus) MMM Ray vs. AABB Represent a line this way … is the Plucker coordinate way