duck2.lt who? rt

rt 5: Distribution ray tracing, spotlights

2017-04-25

This one is about implementing parts of the famous article of Robert Cook.

We apply supersampling over many intervals to get different effects like depth of field, gloss reflections and soft shadows.

Spheres with depth of field. 15.91s

Depth of field effect. We average many rays sent from an aperture to a focal point, resulting in objects further away from the plane of focus to appear blurry.

Glass plates with a point light source. 97.15s

Glass plates with an area light source. 104.47s

The same scene, first illuminated by a point light, second by an area light. Penumbra resulting from the area light can be seen in the second picture. We average many rays sent towards the area light to create the soft shadow.

A glossy metal plate illuminated by an area light source 82s

A glossy metal plate. The gloss is achieved by scattering many rays through a cone instead of one reflection ray.

rt 5 also has spot lights which only illuminate a cone towards a given direction.

Dusty rose dragon, one sample 80.47s

Dusty rose dragon, 100 samples 141.13s

My metallic dragon was given as an assignment :D The first dragon was constructed with one sample per pixel while in the second the average of 100 rays is taken. The difference is easy to spot- look at the heads of dragons.

Rendering times are on a i3-3217U.

Compiled with clang-5.0 on DragonFly BSD.