# Tachyon renderer

One of the advanced features provided by the Tachyon ray tracer is the ability to render scenes with ambient occlusion lighting and semi-transparent objects.

## Parameters

Anti-aliasing samples

  To reduce aliasing effects, the Tachyon raytracer can perform supersampling by computing multiple rays per output pixel. This parameter controls the number of rays.

Direct light

  Enables the parallel light source, which is directed from an angle behind the camera.

Shadows

  Enables cast shadows for the directional light. Not that, with the current Tachyon version, you cannot turn off shadows when ambient occlusion shading is enabled. In this case, you can only turn off the directional light source completely.

Ambient occlusion

  Enabling this lighting technique mimicks some of the effects that occur under conditions of omnidirectional diffuse illumination, e.g. outdoors on an overcast day.

Sample count

  Ambient occlusion is implemented using a Monte Carlo technique. This parameters controls the number of samples to compute. A higher sample number leads to a more even shading, but requires more computation time.