Page History

The following parameters are added to the list of visible settings available from the Global Switches rollout when set to the Advanced Render UI Mode.

Shadows – Enables or disables shadows globally.

Default lights – Controls the default lights in the scene.

Off – Default lights in the scene are always switched off. 
On – Default lights are always switched on when there are no lights in the scene or the Lights option is disabled.
Off with GI  – Default lights are switched off only when Global Illumination is enabled or there are lights in the scene.

Light evaluation – Determines how lights are sampled in scenes with many lights.  For more information, see The Adaptive Lights example below.

Adaptive lights – Uses information from the Light cache to determine which lights to sample. If a Light cache is not used, light tree sampling is used. Depending on the scene, it can be faster than the Full lights evaluation mode.
Full lights evaluation – V-Ray goes through each scene light and evaluates it at each shading point. In scenes with many lights and lots of GI bounces, this leads to a lot of shadow rays being traced and rendering can become extremely slow.  
Light tree ¹ – V-Ray selects a variable number of suitable finite light sources based on proximity and evaluates only those. This mode may speed up the Light Cache and Brute Force calculations for scenes with lots of lights. It can also reduce flickering due to missed light sources. 

Number of lights – Number of lights from the scene that are evaluated by V-Ray when the Light evaluation parameter is  set to Adaptive. To achieve a positive effect from adaptive light sampling, this value must be lower than the actual number of lights in the scene. Lower values make the rendering go faster, but the result is potentially more noisy. Higher values cause more lights to be computed at each hit point, thus producing less noise but increased render times. 

Don't render final image – When this option is enabled, V-Ray only calculates the relevant global illumination maps (photon maps, light maps, irradiance maps). This is a useful option if you are calculating maps for a fly-through animation.

Reflection/refraction – Enables or disables the calculation of reflections and refractions in V-Ray maps and materials.

Maps – Enables or disables texture maps.

Glossy effects – When enabled (the default), glossy reflections are visible in the render. When disabled, all material glossiness settings are ignored, and both reflections and refractions render sharp. This option is useful for test renderings.

Transp. cutoff – Controls when tracing of transparent objects is stopped. If the accumulated transparency of a ray is below this threshold, no further tracing is performed.

Max ray intensity – Suppresses the contribution of very bright rays, which may typically cause excessive noise (fireflies) in the rendered image. Its effect is similar to the Subpixel mapping + Clamp output options of the  Color mapping section, but the Max ray intensity is applied to all secondary (GI/reflection/refraction) rays, as opposed to the final image samples. This allows fireflies to be effectively suppressed but without losing too much HDR information in the final image. Similar to the Subpixel mapping option, the Max ray intensity introduces bias in the rendered image, as it may turn out to be darker than the actual correct result.

This parameter is turned off when loading scenes saved with V-Ray 2.x in order to produce the same results.

Secondary rays bias – A small positive offset that is applied to all secondary rays. This can be used if you have overlapping faces in the scene to avoid the black splotches that may appear. This parameter is also useful when using the 3ds Max Render-to-texture feature. For more information, see The Secondary Rays Bias example below.