ComfyUI Node

H3 Canvas

The canvas H3 samples at — size and duration — carried on the h3_inputs wire so it can be bypassed or swapped between passes. Snaps the duration UP onto H3's legal frame grid (n % 17 == 5), so 5 seconds is 124 frames, and both axes onto the 32px grid, and reports how far past H3's trained envelope you land. Pick the resolution itself with a Resolution node and wire width and height in.

By Nynxz·Created 14 days ago·Updated 5 days ago· 4
H3 Canvas
  • h3_inputs
  • h3_inputs
  • report
width1344
height768
seconds5.0
CategoryNynxz/H3

Inputs (4)

NameTypeDefaultDescription
widthINT134432–16384Canvas width, snapped to the 32px grid — the VAE's /16 then the DiT's 2x2 patch. H3's own envelope is a 768 short edge capped at 768*1344; the report says how far past that you are.
heightINT76832–16384Canvas height, on the same 32px grid.
secondsFLOAT5.00.2–150Duration at 24 fps, snapped UP to the legal frame grid — the report names what you actually get. H3's trained range is ~5-15s; past that the rope runs off the end of what it saw and sung or spoken content degrades into gibberish well before a minute.
h3_inputsoptNYNXZH3_INPUTChain from H3 Image / Video / Audio, or leave unwired. Assets pass through untouched; only the canvas is set.

Outputs (2)

NameTypeDescription
h3_inputsNYNXZH3_INPUTInto H3 Encode, or on through more asset nodes.
reportSTRINGWhat you actually get: the snapped canvas and frame count, the aspect ratio, and how far past H3's base envelope it lands. For the numbers as values, put an H3 Extras on the wire.