This page provides information on the Materials overrides rollout in the Render Settings.
Overview
The Materials overrides control how shading effects will be rendered, and can be used to globally override certain shared parameters throughout the scene. These changes then affect all materials in the scene at a global level.
This tab is not available when using V-Ray GPU renderer.
UI Path: ||Render Settings window|| > Overrides tab > Materials rollout
Parameters
Reflection / Refraction – Enables (default) or disables the calculation of reflections and refractions in V-Ray maps and materials.
Glossy effects – Enables (default) or disables the rendering of glossy effects.
SSS – Enables (default) or disables the rendering of sub-surface scattering effects.
Global max depth – Enables global limiting of the reflection/refraction depth of a material. When this is disabled, the depth is controlled locally by the materials' Reflection Max depth parameter. When this option is enabled, all materials use the Max depth specified in this rollout. For more details, please see the Global Max Depth example below.
Max depth – Specifies the maximum depth when Global max depth is checked. To disable all reflections/refractions in the scene, set this value to 0.
Max. transparency levels – The depth to which transparent objects will be traced. For more details, please see the Max Transparency Levels and Reflection / Refraction example below.
Transparency cutoff – Determines 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.
Allow negative shader colors – Enables the usage of negative values in shaders. This option is useful for including shaders that can accept negative values, such as displacement mapping.
GPU Engine Parameters
SSS – Enables (default) or disables the rendering of sub-surface scattering effects.
Global max depth – Enables global limiting of the reflection/refraction depth of a material. When this is disabled, the depth is controlled locally by the materials' Reflection Max depth parameter. When this option is enabled, all materials use the Max depth specified in this rollout. For more details, please see the Global Max Depth example below.
Max depth – Specifies the maximum depth when Global max depth is enabled. To disable all reflections/refractions in the scene, set this value to 0.
Allow negative shader colors – Enables the usage of negative values in shaders. This option is useful for including shaders that can accept negative values, such as displacement mapping.
Example: Global Max Depth
The images below show the original beauty render along with Global max depth enabled and a Max depth of 1. When Max depth has been set to a value of 1, all reflections and refraction will only have a single bounce and therefore we can see that the windshield's refractions are incorrect.
Original Beauty render with local Reflection Max Depth 5 and a Refraction Max depth of 5
Beauty render with Max depth set to a value of 1, overriding local Reflection Max Depth 5 and Refraction Max depth of 5
Example: Max Transparency Levels and Reflection /Refraction
When all refractions and reflections are disabled, the car retains only its black diffuse color because refractions and reflections are no longer present on any of the materials in the scene, and when Max transparency levels is reduced to a value of 1 nothing is visible through the windshield.
Beauty render with Reflection / Refraction disabled
Beauty render with Max. transparency levels set to a value of 1, overriding local Reflection Max Depth 5 and Refraction Max depth of 5. As a result, we can't see through the windshield.