SoPathTracer

InventorModule

author	MeVis Medical Solutions AG
package	MeVisLab/Standard
dll	SoPathTracer
definition	SoPathTracer.def

Purpose

The SoPathTracer module is the primary rendering module of the MeVis Path Tracer framework.

It should be positioned to the right in the Open Inventor scene, as it will render all objects located in the scene before it. The module itself offers various resolve parameters (such as exposure, denoising, and sharpness), camera parameters (such as aperture), and background colors. It also allows for setting the number of iterations that are rendered.

For available extensions (volumes, meshes, lights, etc.), refer to the MeVis Path Tracer.

Windows

Default Panel

Output Fields

outLightScene (hidden)

name: outLightScene, type: SoNode

An extra scene that given the current bounding box and lights as Inventor objects (to visualize the lighting situation)

outItemModelFld (hidden)

name: outItemModelFld, type: MLBase

An item model that is filled with statistics if enabled.

Parameter Fields

Field Index

1/2 Resolution Tint: Color	Exposure: Float	Noise Reduction: Bool
1/4 Resolution Tint: Color	Filter Size (bloom1FilterSize): Integer	Num Bounces: Integer
1/8 Resolution Tint: Color	Filter Size (bloom2FilterSize): Integer	pickingAlphaThreshold: Float
Aperture: Float	Filter Size (bloom3FilterSize): Integer	Render Mode: Enum
Blend Mode: Enum	Force Full Quality: Bool	Sharpen Blend: Integer
Bloom: Bool	Intensity: Float	Sharpen Start: Integer
Bottom color: Color	Interactive Frame Rate: Float	Sharpness: Float
Current Iteration: Integer	Lerp Threshold (denoiseInitial_lerpThreshold): Float	sRGB background interpolation: Bool
Denoise Final: Bool	Lerp Threshold (denoiseFinal_lerpThreshold): Float	Stop at Iteration: Integer
Denoise Final Iteration: Integer	LerpC (denoiseInitial_lerpC): Float	stopRendering: Trigger
Denoise Initial: Bool	LerpC (denoiseFinal_lerpC): Float	Supported: Bool
Denoise Type: Enum	Luminance Threshold: Float	Tone Mapping: Enum
Direct HDR output: Bool	Luminance Threshold Blend: Float	Top color: Color
Enable Depth Buffer: Bool	maxLuminance: Float	Weight Threshold (denoiseInitial_weightThreshold): Float
Enable Light Geometry Scene: Bool	Noise (denoiseInitial_noise): Float	Weight Threshold (denoiseFinal_weightThreshold): Float
Enable Statistics: Bool	Noise (denoiseFinal_noise): Float

Visible Fields

Direct HDR output

name: directHDROutput, type: Bool, default: FALSE

Aperture

name: aperture, type: Float, default: 0, minimum: 0, maximum: 100

Sets the aperture of the camera lens in millimeters.

This can be used to generate a depth-of-field effect. The current SoCamera focal distance is used as focus. When using the Open Inventor “Seek” button, the focal distance will automatically be updated, which is useful to generate screenshots with depth-of-field effect.

Exposure

name: exposureFactor, type: Float, default: 4, minimum: 0.1, maximum: 50

Tone Mapping

name: toneMapping, type: Enum, default: Exponential

Values:

Title	Name
​Exponential	​Exponential
​Reinhard	​Reinhard
​Filmic	​Filmic
​Uncharted2	​Uncharted2

Render Mode

name: renderMode, type: Enum, default: PathTracing

Values:

Title	Name
​Path Tracing	​PathTracing
​Dvr	​DVR
​Mixed	​Mixed

Blend Mode

name: blendMode, type: Enum, default: Replace

Values:

Title	Name
​Blend	​Blend
​Blend Premultiplied	​BlendPremultiplied
​Replace	​Replace

Top color

name: backgroundTopColor, type: Color, default: 0.300000011920929 0.300000011920929 0.300000011920929

Sets the top color of the background (if no background light illuminates the background).

Bottom color

name: backgroundBottomColor, type: Color, default: 0 0 0

Sets the bottom color of the background (if no background light illuminates the background)

sRGB background interpolation

name: backgroundSRGB, type: Bool, default: TRUE

Interactive Frame Rate

name: interactiveFrameRate, type: Float, default: 30, minimum: 1, maximum: 100

Sets the target frame rate for interaction with the rendering.

The renderer will execute as many iterations as fit within the specified time budget.

Sharpen Start

name: sharpenStart, type: Integer, default: 100

Sharpen Blend

name: sharpenBlend, type: Integer, default: 100

Sharpness

name: sharpness, type: Float, default: 0.75, minimum: 0, maximum: 1

Enable Light Geometry Scene

name: enableLightGeometryScene, type: Bool, default: FALSE

If checked, the generation of an extra scene that contains the light geometry, bounding box and camera frustum is enabled.

Enable Statistics

name: enableStatistics, type: Bool, default: FALSE

If checked, the generation of rendering statistics is enabled. The statistics are provided as an item model output.

Noise Reduction

name: noiseReduction, type: Bool, default: TRUE

Denoise Type

name: denoiseType, type: Enum, default: Denoise_KNN

Values:

Title	Name
​KNN	​Denoise_KNN
​NLM	​Denoise_NLM

Denoise Final Iteration

name: denoiseFinalIteration, type: Integer, default: 100

Denoise Initial

name: denoiseInitial, type: Bool, default: TRUE

Denoise Final

name: denoiseFinal, type: Bool, default: TRUE

LerpC (denoiseInitial_lerpC)

name: denoiseInitial_lerpC, type: Float, default: 0.0099999998, minimum: 0, maximum: 0.33

Noise (denoiseInitial_noise)

name: denoiseInitial_noise, type: Float, default: 4.4699998, minimum: 0, maximum: 10

Weight Threshold (denoiseInitial_weightThreshold)

name: denoiseInitial_weightThreshold, type: Float, default: 0.1, minimum: 0, maximum: 1

Lerp Threshold (denoiseInitial_lerpThreshold)

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

LerpC (denoiseFinal_lerpC)

name: denoiseFinal_lerpC, type: Float, default: 0.2, minimum: 0, maximum: 0.33

Noise (denoiseFinal_noise)

name: denoiseFinal_noise, type: Float, default: 0.31999999, minimum: 0, maximum: 2

Weight Threshold (denoiseFinal_weightThreshold)

name: denoiseFinal_weightThreshold, type: Float, default: 0.02, minimum: 0, maximum: 1

Lerp Threshold (denoiseFinal_lerpThreshold)

name: denoiseFinal_lerpThreshold, type: Float, default: 0.79000002, minimum: 0, maximum: 1

Bloom

name: bloom, type: Bool, default: FALSE

Intensity

name: bloomIntensity, type: Float, default: 1

Luminance Threshold

name: bloomLuminanceThreshold, type: Float, default: 1

Luminance Threshold Blend

name: bloomLuminanceThresholdBlend, type: Float, default: 0.1

1/2 Resolution Tint

name: bloom1Tint, type: Color, default: 1 1 1

1/4 Resolution Tint

name: bloom2Tint, type: Color, default: 1 1 1

1/8 Resolution Tint

name: bloom3Tint, type: Color, default: 1 1 1

Filter Size (bloom1FilterSize)

name: bloom1FilterSize, type: Integer, default: 9

Filter Size (bloom2FilterSize)

name: bloom2FilterSize, type: Integer, default: 9

Filter Size (bloom3FilterSize)

name: bloom3FilterSize, type: Integer, default: 9

Num Bounces

name: numBounces, type: Integer, default: 1, minimum: 1, maximum: 16

Sets the number of ray bounces that are traced.

If set to one, the path tracer only estimates direct light of the direct camera rays. Values larger than one will add indirect light by scattering multiple times.

Stop at Iteration

name: maxIterations, type: Integer, default: 1000

Sets the maximum number of iterations; the renderer stops improving the resulting image when this limit is reached.

Current Iteration

name: currentIteration, type: Integer, persistent: no

Shows the current iteration of the path tracer, which corresponds to the number of samples per screen pixel.

Force Full Quality

name: forceFullQuality, type: Bool, default: FALSE

If checked, the module always renders Stop at Iteration iterations of the current view.

This is useful when used within an OffscreenRenderer module or for movie creation.

Enable Depth Buffer

name: enableDepthBuffer, type: Bool, default: FALSE

If checked, a first hit depth buffer will be generated and it will be passed to OpenGL.

This way, other geometry can be rendered on top of the path tracer rendering with correct depth. Of course these objects will not be illuminated by the path tracer nor will they cast or receive shadows.

Supported

name: supported, type: Bool, persistent: no

Shows whether the current hardware supports the module. The current version required CUDA.

Hidden Fields

stopRendering

name: stopRendering, type: Trigger

maxLuminance

name: maxLuminance, type: Float, default: 10

pickingAlphaThreshold

name: pickingAlphaThreshold, type: Float, default: 0.1