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


The SoPathTracer module is the main rendering module of the MeVis Path Tracer framework. It should be on the right of the Open Inventor scene, since it will render all objects which are located in the scene before it. The module itself offers various resolve parameters (like exposure, denoising, sharpness, ...), camera parameters (aperture) and background colors. It also allows to set the number of iterations that are rendered.

For available extensions (volumes, meshes, lights, ...), have a look at MeVis Path Tracer.


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

Visible Fields


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

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.


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

The exposure of the tone mapping.

Interactive Frame Rate

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

The target frame rate for interaction with the rendering. The renderer will render as many iterations as fit into the given time budget.

Sharpen Start

name: sharpenStart, type: Integer, default: 100

Sharpen Blend

name: sharpenBlend, type: Integer, default: 100


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

Enable Light Geometry Scene

name: enableLightGeometryScene, type: Bool, default: FALSE

Enables the generation of an extra scene that contains the light geometry, bounding box and camera frustum.

Enable Statistics

name: enableStatistics, type: Bool, default: FALSE

Enables rendering statistics, which are provided as item model output.

Noise Reduction

name: noiseReduction, type: Bool, default: TRUE

Denoise Type

name: denoiseType, type: Enum, default: Denoise_KNN


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

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

The maximum number of iterations, the renderer stops improving the result image when this limit is reached.

Current Iteration

name: currentIteration, type: Integer, persistent: no

The current iteration of the path tracer, which equals the number of samples per screen pixel.

Force Full Quality

name: forceFullQuality, type: Bool, default: FALSE

If enabled, the module always renders Stop at Iteration iterations of the current view. This is useful when using it inside of an OffscreenRenderer module or for movie creation.

Background Top Color

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

The top color of the background (if no background light paints the background).

Background Bottom Color

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

The bottom color of the background (if no background light paints the background).

Enable Depth Buffer

name: enableDepthBuffer, type: Bool, default: FALSE

If enabled, a first hit depth buffer will be generated and it will be passed to OpenGL, so that other geometry can be drawn on top of the path tracer rendering with correct depth. Of course these objects will not be lighted by the path tracer nor will they cast or receive shadows.


name: supported, type: Bool, persistent: no

Tells if the current hardware supports the module. The current version required CUDA.

Hidden Fields


name: stopRendering, type: Trigger


name: pickingAlphaThreshold, type: Float, default: 0.1