Distributed Ray tracing or Stochastic Sampling: Understanding jittering

In this method, we take multiple samples of intensities and then take an average. This average is an approximate value for all the intensities for a particular area. A method jittering is used. Here, a particular pixel region is divided to 16 sub regions. After that we obtain the random ray positions  by jittering the center coordinates of each subpixel region by small quantities Δx and Δy. Δx and Δy are the assigned values in the inverter (-0.5, 0.5)  where, (x,y) is the center position of the cell.  Then, jitter position: (x + Δx,  y + Δy).


1) Translucent Objects: Regular Ray tracing fails for translucent objects. Hence, distributed tracing is used.
2) Glossy or partially reflecting surfaces: In a similar way we can’t use a regular ray tracing method for glossy or partially reflecting surfaces. We have to use distributed ray sampling.
3) Distributed Ray tracing is used for taking care of the soft shadows which traditional ray tracing method can’t do.
4) It is used to create more sharper and accurate images by taking care of the depths of the field.
5) Distributed ray tracing has the ability to control the blurring of the animation.

Leave a Reply