# Diffuse#

(MaterialPhysicalDiffuse)

• Category: /Material/Physical
• Default object name: diffuse

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## Description#

Diffuse material.

## Attributes#

Name Type Description
Export Aovs bool Compute and write Aovs defined in the shading graph
Arbitrary Output Variables reference (AovStore) Set the list of extra channels to write to the image.
Light Path Expression Label string Set the material label in light path expressions.
Material Sample Count long Material sample count per pixel.
Diffuse Sampling Multiplier double Material diffuse sample count multiplier.
Russian Roulette double Amount of Russian roulette used on the material samples.
Roughness Noise Optimization double Noise reduction strategy along rough light path.
Multiple Scattering Strength double Strength of compensation for energy lost by multiple scattering.
Diffuse Depth long Maximum diffuse depth.
Opacity double[3] Opacity of the material.
Normal Mode long Define which geometric normal to use for the shading.
Normal Input double Override the shading normal by the one given as input. The value controls the blending with the original normal.
Sidedness long Sidedness of this surface used for this material. 'Single' keeps the original normals no matter what. 'Double' may flip the normal to be oriented toward the incomming direction. 'Invert' flips the original normal no matter what.
Shadow Casting Mode long Defines the properties of the material when casting shadows: fully opaque (regardless of the actual value of the opacity of the material), artistic (user-defined opacity and coloring), pseudo-caustics (cheaply emulating actual refractive caustics) or physical (intrinsic transparency of the material), where the last three are modulated by the opacity of the material.
Shadow Opacity double Defines how dark the shadows cast by this material are.
Shadow Coloring double Defines how much refraction and absorption colors affect shadowing.
Energy Mode long Define whether the front and back contributions are plainly added together, or whether their gains are normalized to guarantee energy conservation.
Mode long BRDF used for the diffuse reflection. The Lambertian model is augmented with a Fresnel term to approximate rough diffuse reflection. The Oren-Nayar BRDF better models back-scattering effects that characterize rough diffuse reflection, either in its classical most basic form or in its more accurate improved form, both solely accounting for a single bounce of light onto the micro-geometry of the surface, or in its full formulation, which additionally accounts for double bounces of light onto the micro-geometry of the surface.
Front Color double[3] Define the diffuse color.
Front Gain double Gain of the diffuse color
Roughness double Roughness of the surface. For Fresnel Lambertian, values smaller than 50% slightly darken grazing angles, and values greater than 50% give the silhouettes a subtle glow (albeit potentially violating energy conservation), whereas a midrange value approaches (but differs from) the pure Lambertian model. For Oren-Nayar, a zero value yields the pure Lambertian model, whereas greater values increase backward scattering phenomena.
Back Color double[3] Amount of light transmitted by the translucent surface.
Back Gain double Gain of the back color.