Troubleshooting
Docs / Appendix D

Troubleshooting

Symptom Likely cause and fix
Path Tracer TOP is black right after an update Its pipeline is compiling in the background (a minute or two the first time). A warning on the TOP says so.
Operators do nothing or talk to the wrong copy Two copies of the HRLW Path Tracer DLL are loaded (for example one in Plugins and one from another folder). Keep exactly one, with the other HRLW files beside it.
Liquid or smoke trails ghost behind moving things Raise DLSS-RR Current Frame Bias (smoke, fire) or the moving-glass bias (Output page).
Smears and trails behind moving geometry Put animated geometry in its own HRLW Geometry POP; use Topology: Deforming Only if the point count is constant; turn Motion Vectors From Points off if points are being reordered.
A static scene is slow to start Specialised pipelines compile on first use of a feature combination. Check the Info CHOP pipeline.
TouchDesigner hangs Look at the log file in %TEMP% (and the .prev one from the last session) for HANG: or EXCEPTION. Set Input Transfer to CPU on the HRLW Geometry POP.
Windows resets the GPU driver A single GPU program ran for about 2 s (TDR). Lower Samples per Frame, Resolution, or turn on Dynamic Resolution.
Fire does not ignite The source needs both fuel and a temperature above Ignition Temperature.
Smoke fills the box Raise Open Side Fade or Smoke Dissipation, or use Source Reach / Thin Gas Cutoff.
Bodies jitter or sink Raise Substeps per Frame or Iterations; watch max_penetration.
Bodies fall through a collider The collider must be inside the Collider Box (or turn on Fit Box to Colliders). Open meshes are thin shells; weld or close a mesh to make it solid (Info CHOP collider_open_tris).
Fractured glass doesn't break Break Strength may be 0, or Glue Prefractured Pieces off; press Reset after changes.
Wetness or burn does nothing The geometry needs non-overlapping Tex/uv in 0..1; the Weathering page names the liquids and solvers (* = all in the network); bypassed solvers are ignored.
A Fracture POP's pieces don't reach Bodies Anything between them (Null, Transform) breaks the direct link; wire them straight.
A parameter is greyed out A Material Preset or Quality/Look preset replaces it, the feature it belongs to is off, the input it needs isn't wired, or Box From / Forces From names another solver.
A POP named in HRLW Geometry POPs doesn't render Only HRLW Geometry POPs render; wire the POP into one (the TOP's warning names it).
Texture maps don't show The geometry needs Tex/uv, or turn on Triplanar for that set (the Path Tracer warns). Check Use Textures, Texture Sets and the TextureId / Texture Set the primitives use.
The wrong smoke renders Volume TOP * found several Volume Solvers and used the first (the TOP warns); name the one you want.
A burning surface makes no flames, or melt doesn't drip The Volume Solver or Liquid POP needs Solver Interaction on (the Weathering page warns).