This example shows how to create a portal light using window geometry. A box is modeled and then split into 2 SOPs - one representing windows and the other walls. The walls are rendered, while the windows are used to specify the portal for an environment light. Toggle on and off the portal to see the render quality difference while rendering in the Render View.
This example shows how to set up the indirectlight object for indirect diffuse lighting. The scene consists of a box that has been extruded several times, containing a light source and the camera. The light has been placed so that all light reaching the camera must bounce more than once inside the scene before reaching the camera. The indirectlight object is configured to generate 1000000 photons. To visualize the photon map, change the rendering mode on the light to "Direct Global Photon Map". To adjust the sampling quality, modify the pixel samples or ray samples on the mantra ROP. The rendering engine used in this example is PBR.
This example shows how to set up the indirectlight object for caustic photon map generation and also how light masks and photon targets should be used. The scene consists of a reflective tube and a point and environment light. Each light has a corresponding indirectlight to generate caustics, with the light mask configured to allow the light to generate photons only from the specified light. The photon target is used to ensure that photons are only sent toward the reflective tube. The mantra ROP will produce deep raster planes for the direct_diffuse component on a per-light basis, showing the diffuse illumination from the two lights and the caustics split into separate planes.
This example highlights several features:
Geometry area lights
Attenuation ramp controls
Surface model specular layers
The example consists of a geometry light based on a wireframe of nurbs curves. The attenuation on the light uses colored keys, allowing for different light colors to be produced at different distances from the light. The ground plane shader uses a surface model with two specular components - one wide component and another narrower glossy component to give a multi-layered appearance.