POPX

Path Tracer

v1.3.0
Tools

Summary

Path Tracer is a GPU-accelerated physically-based renderer using the new ray query extension from TouchDesigner to compute ray-geometry intersections. This operator implements Monte Carlo path tracing with the Disney principled BRDF material model, enabling realistic lighting and material simulation. Path Tracer is currently available on Windows only.

Path Tracer supports both Realtime and Offline rendering modes. Realtime mode includes motion blur and a choice of Custom SVGF or NVIDIA OptiX denoising. Offline mode supports progressive sample refinement for clean convergence. Camera effects include depth of field with focal length and aperture controls, and tone mapping for HDR output. Materials are assigned by connecting a POPX Material operator before the Path Tracer. All lighting, environment maps, and direct lights are controlled via the POPX Light operator.

Parameters

Render ModeRendermode
Selects between realtime and offline rendering modes.
RealtimerealtimeOfflineoffline
Refine SamplesRefinesamples
Enables progressive sample refinement in offline mode.
Max Refine SamplesMaxrefinesamples
Maximum number of refinement samples to accumulate in offline mode.
DoneDone
Read-only indicator showing refinement completion status.
Render TOPRendertop
Reference to Render TOP providing camera and viewport settings that the path tracer will render to.
ResetReset
Pulse to reset progressive accumulation and restart rendering.
Lock InputLockinput
Freeze input geometry to prevent updates during progressive rendering.
Rays per PixelRaysperpixel
Number of rays cast per pixel per frame.
Max BouncesMaxbounces
Maximum ray bounce depth for global illumination.
Render EmissivesRenderemissives
Enables rendering of emissive materials as light sources.
Enable Microfacet RefractionMicrofacetrefraction
Enables microfacet-based refraction model for rough transmissive materials.
Enable Firefly ClampEnablefireflyclamp
Clamps extremely bright samples to reduce firefly artifacts.
Firefly ClampFireflyclamp
Maximum brightness value for firefly clamping.
Focal LengthFocallength
Distance from camera where objects are in sharp focus.
ApertureAperture
Camera aperture size for depth of field.
Show Focal PlaneShowfocalplane
Displays the focal plane in the viewport for visualization.
Focal Plane SizeFocalplanesize
Size of the focal plane visualization.
Enable Motion BlurEnablemotionblur
Enables motion blur effect in realtime mode.
StrengthBlurstrength
Motion blur intensity.
SamplesBlursamples
Number of samples for motion blur quality.
Enable Tone MapEnabletonemap
Apply tone mapping to convert HDR output to display range.
ExposureExposure
Exposure multiplier for tone mapping.
GammaGamma
Gamma correction value for tone mapping output.
DenoiserDenoiser
Selects the denoising method.
NonenoneCustom SVGFsvgfNVIDIA OptiXoptixNVIDIA DLSSdlss
Use Motion VectorsUsemotionvectors
Uses motion vectors for temporal reprojection accuracy.
Normal RejectNormalreject
Threshold for rejecting temporal samples based on surface normal differences.
Depth RejectDepthreject
Threshold for rejecting temporal samples based on depth differences.
Albedo RejectAlbedoreject
Threshold for rejecting temporal samples based on albedo differences.
Diffuse History BlendDiffusehistoryblend
Temporal blend factor for diffuse lobe history accumulation.
Diffuse Variance BlendDiffusevarianceblend
Temporal blend factor for diffuse variance estimation.
Specular History BlendSpecularhistoryblend
Temporal blend factor for specular lobe history accumulation.
Specular Variance BlendSpecularvarianceblend
Temporal blend factor for specular variance estimation.
Diffuse Atrous PassesDiffpasses
Number of a-trous wavelet filter passes for diffuse spatial denoising.
Diffuse Color SensitivityDiffcolor
Sensitivity to color differences in diffuse spatial filtering.
Diffuse Normal SensitivityDiffnormal
Sensitivity to surface normal differences in diffuse spatial filtering.
Diffuse Depth SensitivityDiffdepth
Sensitivity to depth differences in diffuse spatial filtering.
Specular Blur PassesSpecpasses
Number of a-trous wavelet filter passes for specular spatial denoising.
Specular Color SensitivitySpeccolor
Sensitivity to color differences in specular spatial filtering.
Specular Normal SensitivitySpecnormal
Sensitivity to surface normal differences in specular spatial filtering.
Specular Depth SensitivitySpecdepth
Sensitivity to depth differences in specular spatial filtering.
Smooth ReflectionsSmoothreflections
Amount of specular reflection smoothing based on roughness.
Plugin PathOptixplugin
File path to the NVIDIA OptiX denoiser plugin.
Re-InitOptixreinitpulse
Re-initializes the OptiX denoiser.
History BlendOptixhistoryblend
Temporal history blend factor for OptiX denoiser.
Normal RejectOptixnormalreject
Threshold for rejecting temporal samples based on surface normal differences for OptiX denoiser.
Depth RejectOptixdepthreject
Threshold for rejecting temporal samples based on depth differences for OptiX denoiser.
Albedo RejectOptixalbedoreject
Threshold for rejecting temporal samples based on albedo differences for OptiX denoiser.
Plugin PathDlssplugin
File path to the NVIDIA DLSS denoiser plugin.
Re-InitDlssreinitpulse
Re-initializes the DLSS denoiser.
DLSS QualityQuality
Quality preset for the DLSS denoiser.
Ultra PerformancePerformanceBalancedQualityDLAA
Free Extra GPU MemoryFreeextragpumem
Free memory that has accumulated when output memory has grown and shrunk.

Inputs

Input 0POP
Geometry

Outputs

Output 0POP
POPX_out1