Path Tracer v1.3.0

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

Page: Path Tracer

Render Mode Rendermode – – Selects between realtime and offline rendering modes.
Realtime realtime
Offline offline
Refine Samples Refinesamples – Enables progressive sample refinement in offline mode.
Max Refine Samples Maxrefinesamples – Maximum number of refinement samples to accumulate in offline mode.
Done Done – Read-only indicator showing refinement completion status.
Render TOP Rendertop – Reference to Render TOP providing camera and viewport settings that the path tracer will render to.
Reset Reset – Pulse to reset progressive accumulation and restart rendering.
Lock Input Lockinput – Freeze input geometry to prevent updates during progressive rendering.
Rays per Pixel Raysperpixel – Number of rays cast per pixel per frame.
Max Bounces Maxbounces – Maximum ray bounce depth for global illumination.
Render Emissives Renderemissives – Enables rendering of emissive materials as light sources.
Enable Microfacet Refraction Microfacetrefraction – Enables microfacet-based refraction model for rough transmissive materials.
Enable Firefly Clamp Enablefireflyclamp – Clamps extremely bright samples to reduce firefly artifacts.
Firefly Clamp Fireflyclamp – Maximum brightness value for firefly clamping.
Focal Length Focallength – Distance from camera where objects are in sharp focus.
Aperture Aperture – Camera aperture size for depth of field.
Show Focal Plane Showfocalplane – Displays the focal plane in the viewport for visualization.
Focal Plane Size Focalplanesize – Size of the focal plane visualization.
Enable Motion Blur Enablemotionblur – Enables motion blur effect in realtime mode.
Strength Blurstrength – Motion blur intensity.
Samples Blursamples – Number of samples for motion blur quality.
Enable Tone Map Enabletonemap – Apply tone mapping to convert HDR output to display range.
Exposure Exposure – Exposure multiplier for tone mapping.
Gamma Gamma – Gamma correction value for tone mapping output.

Page: Denoiser

Denoiser Denoiser – – Selects the denoising method.
None none
Custom SVGF svgf
NVIDIA OptiX optix
NVIDIA DLSS dlss
Use Motion Vectors Usemotionvectors – Uses motion vectors for temporal reprojection accuracy.
Normal Reject Normalreject – Threshold for rejecting temporal samples based on surface normal differences.
Depth Reject Depthreject – Threshold for rejecting temporal samples based on depth differences.
Albedo Reject Albedoreject – Threshold for rejecting temporal samples based on albedo differences.
Diffuse History Blend Diffusehistoryblend – Temporal blend factor for diffuse lobe history accumulation.
Diffuse Variance Blend Diffusevarianceblend – Temporal blend factor for diffuse variance estimation.
Specular History Blend Specularhistoryblend – Temporal blend factor for specular lobe history accumulation.
Specular Variance Blend Specularvarianceblend – Temporal blend factor for specular variance estimation.
Diffuse Atrous Passes Diffpasses – Number of a-trous wavelet filter passes for diffuse spatial denoising.
Diffuse Color Sensitivity Diffcolor – Sensitivity to color differences in diffuse spatial filtering.
Diffuse Normal Sensitivity Diffnormal – Sensitivity to surface normal differences in diffuse spatial filtering.
Diffuse Depth Sensitivity Diffdepth – Sensitivity to depth differences in diffuse spatial filtering.
Specular Blur Passes Specpasses – Number of a-trous wavelet filter passes for specular spatial denoising.
Specular Color Sensitivity Speccolor – Sensitivity to color differences in specular spatial filtering.
Specular Normal Sensitivity Specnormal – Sensitivity to surface normal differences in specular spatial filtering.
Specular Depth Sensitivity Specdepth – Sensitivity to depth differences in specular spatial filtering.
Smooth Reflections Smoothreflections – Amount of specular reflection smoothing based on roughness.
Plugin Path Optixplugin – File path to the NVIDIA OptiX denoiser plugin.
Re-Init Optixreinitpulse – Re-initializes the OptiX denoiser.
History Blend Optixhistoryblend – Temporal history blend factor for OptiX denoiser.
Normal Reject Optixnormalreject – Threshold for rejecting temporal samples based on surface normal differences for OptiX denoiser.
Depth Reject Optixdepthreject – Threshold for rejecting temporal samples based on depth differences for OptiX denoiser.
Albedo Reject Optixalbedoreject – Threshold for rejecting temporal samples based on albedo differences for OptiX denoiser.
Plugin Path Dlssplugin – File path to the NVIDIA DLSS denoiser plugin.
Re-Init Dlssreinitpulse – Re-initializes the DLSS denoiser.
DLSS Quality Quality – – Quality preset for the DLSS denoiser.
Ultra Performance Ultra Performance
Performance Performance
Balanced Balanced
Quality Quality
DLAA DLAA

Page: Common

Free Extra GPU Memory Freeextragpumem – Free memory that has accumulated when output memory has grown and shrunk.

Inputs

Input 0 POP – Geometry

Outputs

Output 0 POP – POPX_out1