SoPathTracerMaterial

InventorModule
author Florian Link
package MeVisLab/Standard
dll SoPathTracer
definition SoPathTracer.def

Purpose

The SoPathTracerMaterial module provides the material properties for geometry and volumes of a SoPathTracer scene. It is typically either used inside the input scene of e.g. SoPathTracerMesh or as direct input of modules that have a "inMaterial" input.

The material parameters are intentionally mapped to the range 0-1 to make it easier for the user to specify meaningful parameters. It also allows to specify the parameters in LUTs.

Windows

Default Panel

../../../Projects/MeVisPathTracer/SoPathTracer/Modules/mhelp/Images/Screenshots/SoPathTracerMaterial._default.png

Parameter Fields

Field Index

Alpha: Float Enable Volume Shader: Bool Shader Type: Enum
Alpha Mode: Enum Gradient Factor: Float Sheen: Float
Anisotropy: Float Horizon Color: Color Sheen Tint: Float
Back Scattering: Float Horizon Scattering: Float Shininess: Float
Clearcoat: Float Material: Enum Specular: Float
Clearcoat Gloss: Float Metallic: Float Specular Intensity: Float
Diffuse: Color Phase Function: Enum Specular Tint: Float
Diffuse Mode: Enum Phase Function Param: Float Subsurface: Float
Emissive: Color Roughness: Float Visible: Bool

Visible Fields

Visible

name: visible, type: Bool, default: TRUE

If enabled, the meshes that use this material are visible. This can be used to show/hide meshes in the scene of a SoPathTracerMesh without complete scene re-computation.

Material

name: material, type: Enum, default: Material_Microfacet

The type of the material.

Values:

Title Name Description
Matte Material_Matte A matte material with lambertian diffuse shading (without any fresnel effects)
Velvet Material_Velvet A material the mimicks velvet/cloth (experimental).
Microfacet Material_Microfacet A material that offers a microfacet BRDF with lambertian diffuse and blinn/fresnel specular.
Principled Material_Principled The multi-purpose material that offers various parameters. See https://disney-animation.s3.amazonaws.com/library/s2012_pbs_disney_brdf_notes_v2.pdf for details.

Alpha Mode

name: alphaMode, type: Enum, default: Multiply

The alpha combination mode (only applied for meshes).

Values:

Title Name
Overwrite Overwrite
Multiply Multiply
Ignore Ignore

Diffuse Mode

name: diffuseMode, type: Enum, default: Multiply

The diffuse combination mode.

Values:

Title Name
Overwrite Overwrite
Multiply Multiply
Ignore Ignore

Specular

name: specular, type: Float, default: 0.5, minimum: 0, maximum: 1

The specular parameter of the microfacet model (0 - matte/rough material, 1 - very specular/glossy material).

Shininess

name: shininess, type: Float, default: 0.5, minimum: 0, maximum: 1

The shininess (mapped to Blinn exponent of microfacet BRDF).

Specular Intensity

name: specularIntensity, type: Float, default: 0.2, minimum: 0, maximum: 1

The intensity of the specular contribution.

Horizon Scattering

name: horizonScattering, type: Float, default: 0.5, minimum: 0, maximum: 1

Velvet material property.

Back Scattering

name: backScattering, type: Float, default: 0.5, minimum: 0, maximum: 1

Velvet material property.

Horizon Color

name: horizonColor, type: Color, default: 1 1 1

Velvet horizon color.

Metallic

name: metallic, type: Float, default: 0, minimum: 0, maximum: 1

Anisotropy

name: anisotropy, type: Float, default: 0, minimum: 0, maximum: 1

Roughness

name: roughness, type: Float, default: 0.5, minimum: 0, maximum: 1

Specular Tint

name: specularTint, type: Float, default: 0, minimum: 0, maximum: 1

Sheen Tint

name: sheenTint, type: Float, default: 0, minimum: 0, maximum: 1

Sheen

name: sheen, type: Float, default: 0, minimum: 0, maximum: 1

Clearcoat Gloss

name: clearcoatGloss, type: Float, default: 0, minimum: 0, maximum: 1

Clearcoat

name: clearcoat, type: Float, default: 0, minimum: 0, maximum: 1

Subsurface

name: subsurface, type: Float, default: 0, minimum: 0, maximum: 1

Alpha

name: alpha, type: Float, default: 1, minimum: 0, maximum: 1

The alpha value of the geometry (not used for volumes).

Diffuse

name: diffuse, type: Color, default: 1 1 1

The diffuse color. Depending on the Diffuse Mode it overwrites or it combined with the geometry diffuse color.

Emissive

name: emissive, type: Color, default: 0 0 0

Sets the emissive color.

Enable Volume Shader

name: enableVolumeShader, type: Bool, default: FALSE

Enabled overwriting of the volume shader settings if the material is used on a volume.

Shader Type

name: volumeShaderType, type: Enum, default: Shader_Hybrid

Selects the volume shader type.

Values:

Title Name Description
Phase Shader_Phase Uses the phase function for shading the volume (the gradients of the volume are not used for rendering)
Brdf Shader_Brdf Uses the material BRDF for shading, the gradients of the volume are used.
Hybrid Shader_Hybrid Selects between Phase and BRDF shading depending on the gradient magnitude. The gradient magnitude is scaled by Gradient Factor.

Phase Function

name: volumePhaseFunction, type: Enum, default: Phase_Isotropic

Selects the phase function to use.

Values:

Title Name Description
Isotropic Phase_Isotropic Use the isotropic phase function (all directions on the unit sphere have the same probability)
Henyey Greenstein Phase_HenyeyGreenstein Use the Henyey-Greenstein phase function. The Phase Function Param specifies the "g" parameter of the phase function, with meaningful values between 0.5 and -0.5.

Gradient Factor

name: volumeGradientFactor, type: Float, default: 3, minimum: 0, maximum: 200

The gradient factor.

Phase Function Param

name: volumePhaseFunctionParam, type: Float, default: 0

Extra parameter for volume phase functions.