Command-line render

render.sh (Windows: render.bat) in the install folder renders a script with no window and no display. It takes the standard command-line render flags and prints the usual progress lines, so a render-farm plugin written for nuke -x can call it instead.

./render.sh -x -F 1-100 -X Write1 shot.nk
./render.sh -F 1001-1100x5 --cont -m 8 comp.oink
./render.sh --cpu -F 1 comp.oink          # no GPU: software rendering

FlagsCopy Anchor Link

Other flags a farm may pass (--nukex, --priority, -c, …) are accepted and ignored.

OutputCopy Anchor Link

The first line says what it renders on, so a farm log shows at once when a machine lost its GPU:

Renderer: GPU, NVIDIA GeForce RTX 4090/PCIe/SSE2 (OPENGL, NVIDIA Corporation)
Renderer: CPU (software: llvmpipe), llvmpipe (LLVM 20.1.8, 256 bits) (OPENGL, Mesa)

On a software renderer that you did not ask for (--cpu) it also prints WARNING: no GPU: .... Add --require-gpu to make that an error instead (exit code 3). The pixels are the same either way: a CPU render matches the GPU one to within float rounding.

For each frame it prints the same lines Nuke does:

Frame 1001 (1 of 100)
Writing /shots/sh010/comp/sh010_comp.1001.exr took 0.42 seconds
...
Total render time: 43.18 seconds

Each frame is also checked for NaN or infinite pixels and for an all-black frame. A flagged frame is still written, and a line like WARNING: Write1: frame 1004: black frame (every RGB value is 0) is printed.

Errors start with ERROR:, for example ERROR: Write1: frame 1004: bad output ... (file removed).

Checks before and after renderingCopy Anchor Link

Before the first frame it stops, listing every problem at once, when:

• input files are missing (the list shows each missing file and the Read node that needs it);
• an OFX plugin or a gizmo the script uses is not installed;
• an output folder does not exist (unless the Write has create directories on) or cannot be written to;
• there is no usable GPU (use --gpu-index to pick another one, or --cpu).

Image frames are written to a hidden temporary file in the same folder and renamed when complete, so nothing sees a half-written frame. After each file is written it is read back: it must exist, be larger than zero bytes, open, have every pixel readable, and have the expected resolution and channels. A partial or broken file counts as a failed frame and is deleted.

Exit codesCopy Anchor Link

Stopping a renderCopy Anchor Link

The first SIGTERM or Ctrl-C lets the frame being rendered finish, then stops. A second one aborts that frame and deletes its partial file. With --cont, frames that fail are skipped and the exit code is still 1.

On a render farmCopy Anchor Link

• Point the farm's Nuke executable at render.sh (or render.bat) and keep its usual Nuke command line.
• Every GPU render takes the machine's GPU lease, so one GPU job runs at a time on a machine: a second render (or an AI job) waits for the first. Renders with --cpu do not need the lease.
• A machine with no GPU can render with --cpu.