Operators
The Photon RTXPT operator set and how a scene assembles.
Photon RTXPT installs one renderer and three helper operators. The renderer owns the GPU pipeline; the helpers describe the scene.
| Operator | Family | Role |
|---|---|---|
Photon RTXPT | TOP | The renderer — traces, denoises, outputs |
Photon Material | COMP | A material definition bound by path or wildcard |
Photon Light | COMP | A light — area, sun, dome, or mesh emitter |
Photon Camera | COMP | Physical camera: focal length, aperture, EV |
Assembling a scene
render = op('/project1/photon_rtxpt1')
render.par.geometry = '/project1/geo1' # any SOP hierarchy
render.par.camera = '/project1/photoncam1' # falls back to a default cam
render.par.lights = '/project1/photonlight*' # wildcard collectThe renderer collects by path pattern — the same wildcard rules as any
TouchDesigner parameter that takes an OP path. Drop a new
Photon Light matching the pattern and it joins the next cook.
Helper COMPs cook at parameter-change time only. The renderer is the only operator doing per-frame work — keep your cull flags on the SOPs feeding it, not on the Photon COMPs.
Cook behavior
- Static scene → progressive accumulation, up to the
Max Samplescap - Camera move → accumulation resets, denoiser bridges the gap
- Geometry edit → only the touched acceleration structure rebuilds
Time-sliced CHOP exports into material parameters force a full reset every
frame. Route animated values through the Photon Material COMP's dedicated
Animate page instead — those update without invalidating accumulation.