©Anton Podvalny

In this chapter we'll cover the rest of the settings plugins, which are more rarely used.

SettingsRaycaster

The SettingsRaycaster plugin has one main parameter of interest:

embreeUse - You'd want to set this to 1 (default is 0), because it increases raytracing performance.

 

SettingsRegionsGenerator

SettingsRegionsGenerator controls the size and order of generation of buckets in production mode.

  • xc - The maximum width of buckets in pixels
  • yc - The maximum height of buckets in pixels
  • xymeans - The size in pixels or number of regions - 0:Size in pixels; 1:Number of regions
  • seqtype - The ordering algorithm - 0:Top-Bottom; 1:Left-Right; 2:Checker; 3:Spiral; 4:Triangulation; 5:Hilbert curve; 6:Random
  • reverse - If true, reverse the order in which buckets are generated
  • dynbuckets - Whether to split the final buckets into smaller pieces for better processor utilization - 0:Disabled; 1:Enabled; 2:Enabled (legacy algorithm)

SettingsOptions

Global Switches

The global switches allow you to control various aspects of the renderer globally. SettingsOptions holds many miscellaneous options, some of which are:

  • geom_displacement - True if displacement should be computed.
  • geom_doHidden - True if hidden geometry should be used.

 

Lighting Parameters

  • light_doLights - Enables or disables lights globally. Note that if you disable this option, V-Ray will use default lights. If you do not want any direct lighting in your scene, you must disable this option and set Default lights to false.
  • light_doDefaultLights - Controls the default lights in the scene.
    • False - Default lights in the scene will be always switched off.
    • True - Default lights are always switched on when there are no lights in the scene or when you have disabled the light_doLights.
  • light_doHiddenLights - Enables or disables the usage of hidden lights. When this option is enabled, lights are rendered regardless of whether they are hidden or not. When this option is disabled, any lights that are hidden for any reason (either explicitly or by type) will not be included in the rendering.
  • light_doShadows - Enables or Disables shadows globally.
  • light_onlyGI - When this option is enabled, direct lighting will not be included in the final rendering. Note that lights will still be considered for GI calculations, however in the end only the indirect lighting will be shown.
  • light_disableSelfIllumination - If true - will disable self-Illumination
  • num_probabilistic_lights - The number of lights to sample for probabilistic or adaptive lighting if probabilistic_lights_on is not 0. Probabilistic lighting improves render speeds with hundreds and thousands of lights by only sampling a few of the "important" light sources. Adaptive lighting is an even better algorithm and is the recommended option. The default value for adaptive lighting should be 8.
  • probabilistic_lights_on - This option enables optimized sampling for scenes with many lights. Use value 2 for the recommended adaptive lighting algorithm. Value 1 uses only probabilistic lighting which is inferior. When this option is disabled (0), for each hit point, V-Ray goes though each scene light and evaluates it. In scenes with many lights and lots of GI bounces, this leads to a lot of shadow rays being traced, to the point that rendering becomes extremely slow. When this option is enabled, V-Ray chooses the specified number of lights and evaluates only those. Lower values make the rendering faster, but potentially more noisy. Higher values cause more lights to be computed at each hit point, thus producing less noise, but increasing render times. For more information, see The Probabilistic Lights example below. When loading scenes saved with V-Ray 2.x, the option is turned off in order to produce the same result.

 

Example: Probabilistic Lights

It is highly recommended to use adaptive lights instead of probabilistic lights.

This is a scene with over 1000 spherical Area lights with the Cutoff threshold set to 0.0 (no cutoff). Both images were rendered with the Progressive image sampler for the same amount of time. When the Probabilistic lights option is disabled, the rendering is very noisy. When the Probabilistic lights option is enabled and set to 8 lights, the image is much cleaner as V-Ray is able to compute more GI rays, which are the main source of noise in this scene.

Material Parameters

  • mtl_reflectionRefraction - Boolean, enables or disables the calculation of reflections and refractions in V-Ray maps and materials.
  • mtl_limitDepth - Global limit to reflection/refraction depth. When this option is disabled, the depth is controlled locally by materials and maps. When this option is enabled, all materials and maps use the depth specified in mtl_maxDepth.
  • mtl_maxDepth - The maximum number of bounces to trace for reflections and refractions. Defaults to 5. Only increase if you need to. In Interactive mode set SettingsRTEngine::trace_depth instead.
  • mtl_doMaps - Boolean, enables or disables texture maps.
  • mtl_filterMaps - Boolean, enables or disables texture map filtering. When enabled, the depth is controlled locally by texture map settings. When disabled, no filtering is performed.
  • mtl_SSSEnabled - boolean
  • mtl_filterMapsForSecondaryRays - Enables or disables texture filtering during calculations of GI and glossy reflections/refractions. When disabled (the default), texture maps are not filtered for GI and glossy reflections/refractions in order to speed up the calculations. If this option is enabled, textures will be filtered in these cases.
  • mtl_transpMaxLevels - The depth to which transparent objects will be traced.
  • mtl_transpCutoff - Controls when tracing of transparent objects will be stopped. If the accumulated transparency of a ray is below this threshold, no further tracing will be performed.
  • mtl_override_on - Override the scene materials when rendering. All objects will be rendered with the chosen material, if one is selected, or with their default wireframe materials if no material is specified.
  • mtl_glossy - When enabled, all glossy reflections in the scene are replaced with non-glossy ones. This option is useful for test renderings.
  • mtl_uninvertedNormalBump - If true the normal bump in tangent space will not be inverted on flipped UVs

 

Indirect Illumination Parameters

  • gi_dontRenderImage - When this option is enabled, V-Ray will only calculate the relevant global illumination maps (photon maps, light maps, irradiance maps). Set to 1 if you're baking a GI prepass (Irradiance Map or Light Cache) file and want to skip the actual rendering.
  • gi_texFilteringMultiplier - GI texturing filtering multiplier

 

Raytracing Parameters

  • ray_max_intensity and ray_max_intensity_on - If you enable it with ray_max_intensity_on, ray_max_intensity clamps the values of some very bright samples to avoid the hard to clean up "firefly" artefacts at the cost of slightly wrong overall image brightness.
  • ray_bias - A small positive offset that will be 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. For more information, see The Secondary Rays Bias example below.

 

Example: Secondary Rays Bias

This example shows the effect of the Secondary rays bias parameter. The scene below has a box object with a height of 0.0, which the top and bottom of the box occupy exactly the same region in space. Due to this, V-Ray cannot resolve unambiguously intersections of rays with these surfaces.

The first image shows what happens when you try to render the scene with the default settings. You can see the splotches in the GI solution, caused by the fact that rays randomly intersect one or the other surface:

In the second image below, the Secondary rays bias is set to 0.001, which offsets the start of each ray a little bit along its direction. In effect, this makes V-Ray skip the problematic surface overlaps and render the scene correctly:

Note that the Secondary rays bias affects only things like GI, reflections, etc. In order to render the scene properly, the material assigned to the box has its 2-sided option checked. This is so that the object looks in the same way regardless of whether the camera rays hit the top or the bottom of the box. If the material did not have this option checked, it would appear "noisy" even though the Secondary rays bias is greater than 0.0:

Miscellaneous

  • misc_transferAssets - Try to transfer missing assets in distributed rendering (DR) from the client to the render server. Disabled by default.
  • misc_abortOnMissingAsset - Fail DR if an asset can't be found. Disabled by default.
  • misc_lowThreadPriority - Render with low thread priority to improve multitasking. Disabled by default.

 

Others

  • geom_backfaceCull - If true, back faces will be invisible to camera and shadow rays
  • dr_assetsCacheLimitType - Type of the assets cache limit
  • dr_assetsCacheLimitValue - Value of the assets cache limit
  • dr_overwriteLocalCacheSettings - If true the client's cache settings will overwrite server settings
  • ray_max_intensity_on - Enable clamping of secondary rays
  • ray_max_intensity - The max secondary ray intensity when ray_max_intensity_on is enabled
  • probabilistic_vol_on - Enable probabilistic volumetric sampling
  • probabilistic_vol_samples - The number of probabilistic samples to shade for primary/shadow rays when probabilistic_vol_on is true
  • probabilistic_vol_gi_samples - The number of probabilistic samples to shade for gi/glossy when probabilistic_vol_on is true

 

Saved image settings

If you save the rendered image from the VFB and not from an AppSDK API, the corresponding Settings{JPEG|PNG|EXR|TIFF} plugin controls compression quality and bits per channel. You may need to change these according to your needs.

SettingsMotionBlur

If you want to enable motion blur, set the SettingsMotionBlur plugin on parameter to 1. It also has the geom_samples parameter that affect quality, but may cost a lot of render time if increased. It should equal the number of geometry samples in the geometry data if it is non-static.

SettingsLightLinker

The SettingsLightLinker plugin allows you to define include or exclude lists for lights and objects, so that for example specific lights do not affect some objects etc. Refer to the plugin parameter metadata for explanations.

SettingsCaustics

SettingsCaustics can enable improved rendering of caustic effects with photon mapping. This also requires setting some material parameters to make it work.

See this lesson for some details on caustics.

SettingsCameraDof

If you are not using CameraPhysical for depth of field, you can use SettingsCameraDof instead.

  • on - Set to true to enable DoF.
  • aperture - The size of the camera aperture in scene units. Note that increasing this number corresponds to decreasing the physical camera's F-number.
  • focal_dist - Distance from the camera to the focus plane in scene units.
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