The Advanced Lighting tab
The Advanced Lighting Tab provides more detailed options for controlling lights.
Its controls are:
- Engine - Standard (Packet Mode), Path Tracer, or Hybrid. See: nXtRender Rendering Engines
- Sky. This defines a hemispherical light source, infinitely far away from your model. There are four options for Sky lighting: Off, Auto, HDRi , and Color and Image. The automatic Sky provides an analytical model based on real-world sky conditions. The parameters for automatic Sky can be adjusted on the Sun tab.
- Sun. The Sun is a directional light source infinitely far away from the model. The Sun control allows the Sun to be turned on and off.
- Studio Brightness. Studio Brightness reduces the brightness of the Sun and Sky by a factor of 20, mimicking the interior lighting levels of a photographer's studio.
- Lights. This enables and disables artificial lighting.
- Indirect. This is the lighting reflected off of surfaces. By default, it is on for interior lighting presets and off for exteriors and studio models. It is also possible to turn on indirect lighting for exterior renderings.
- Indirect Bounces. This controls the number of reflections caused by an indirect light, ranging from one to four.
- Color Bleed. Color Bleed controls the amount of color transfer associated with each indirect bounce. It varies from zero to one.
- Ambient. - High, Medium or Low
- Automatic Daylight Portals. A daylight portal is an opening for Sun and Sky lighting for an interior rendering. Automatic Daylight Portals sets all transparent materials as daylight portals.
- Monte Carlo Reflections. This checkbox is intended to resolve blurry reflections containing small, bright areas. This comes at a performance cost. The standard reflection algorithm almost always converges faster, even with blurry reflections.
- Disable caustics
- Reflective Bounces.
- Refractive Bounces.
- Lights Per Pass. A specified number of lights are rendered each pass. Increasing the Lights Per Pass increases the information contained in each pass, but requires more time per pass.
- Channels. This controls the number of channels for multi-channel rendering.
- material Glow Channel
Only available with Path Tracer or Hybrid Engine.
- Scattering - controls the probability of the light encountering a particle in the fog boundary. Higher numbers produce denser fogs. The default of 20% is adequate for many uses.
- Scattering Direction - controls how the light is scattered. Values > 0 produce forward scattering. Values < 0 produce backward scattering, similar to reflection. The default of 0.2 produces a pattern which resembles water droplets suspended in air.
- Absorption - is the probability of light being absorbed in the fog boundary. Higher numbers produce darker fogs. This is normally left at 0%.
- Fog Color
- If Scattering or Absorption is too high, then you may just get a dark rendering with no light passing through.