# Transmission#

(MaterialPhysicalTransmission)

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

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## Description#

A refraction physical 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.
Glossy Transmission Sampling Multiplier double Material glossy transmission 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.
Specular Transmission Depth long Maximum specular transmission depth.
Glossy Transmission Depth long Maximum glossy transmission depth.
Volume Depth long Maximum volume 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.
Refractive Caustics long Refractive caustics computation mode.
Color double[3] Set the refraction color of the material.
Gain double Gain of the refraction color.
Exit Color double[3] Set the refraction color when there is no more bounce along the path.
Index Of Refraction double Set the index of refraction.
Roughness double Roughness of the refraction surface.
Btdf long BTDF used for the specular lobe.
Anisotropy Mode long Controls how the anisotropy behaves. Stretch increases the roughness along Y axis, whereas Squash reduces the roughness along Y axis.
Anisotropy double Anisotropy of the refraction surface.
Anisotropy Space long Space in which the specular lobe anisotropy direction is expressed. Tangent UV space uses a frame defined by the UV mapping of the textures connected to the specular attributes. Tangent parametric uses, as the name suggests, the parametric frame. Finally, Object space uses the current object frame.
Anisotropy Direction double[3] Initial direction of specular lobe anisotropy (before a potential rotation) expressed in the space selected above.
Anisotropy Rotation double Rotates the anisotropy direction of the specular lobe around the normal (100% equates to 180 degrees).
Transmittance Color double[3] Set the transmittance color of the material.
Transmittance Density double Set the transmittance density of the material.
Transmission Scatter double[3] Color of the scattering
Transmission Scatter Anisotropy double Anisotropy of the scattering.