How to Render Using the GPU in Nuke (macOS)

If you’re not a huge post house and you wanna use Nuke on your home Mac, you should set up your nuke command line tools, so that you can render out your comps using the GPU.

Normally, Nuke uses the CPU to render out frames, and that can be painfully slow.

I’m posting the following instructions since I couldn’t find any info online on exactly how to do this, and it took me a little while to figure it out.

Set Up the Nuke Command Line Tools on macOS

To set up your command line to use Nuke, you should do the following:

Create a permanent Nuke Command Line Alias

1. Open a Terminal window.
2. Type cd / and press ENTER.
3. Type ls -a and you should see your .bash_profile (it’s a hidden file, you can only see it with the -a flag)
4. Type sudo nano .bash_profile, it will ask you for your admin password (the same password you use to access your computer. You won’t see asterisks or anything, just press ENTER when you’re done).
5. Add the following line at the bottom of the file: alias nuke=’/Applications/Nuke11.1v1/Nuke11.1v1.app/Contents/MacOS/Nuke11.1v1′  (for some reason, the official guide from TheFoundry a wrong file path)
6. Press Cmd + X, then Y (for YES), then enter to confirm the file name (.bash_profile)
7. Now you can either restart your computer, or simply reload your bash profile by typing the following: source .bash_profile and press ENTER.
8. Now you can launch Nuke from Terminal by simply typing ‘nuke’

Rendering Your Comp With the GPU on macOS

1. Make sure your comp has a write node, set up with all the parameters you need and outputting to the directory you want it to.
2. In a Terminal window, navigate to the path of your .nk file (for example, cd /Users/username/Documents/)
3. Verify your file is there by typing ls (or start typing out the filename and press TAB – if it autocompletes to the full name, it’s there).
4. Now type the render command, as follows: nuke -F 1-100 -xi –gpu Render-Test.nk
5. When you press ENTER, you’ll get a nice scrolling list of the frames being rendered, as well as the ETA for the render.

The -F 1-100 is the frames you wanna render out. If you omit this, it will render out the whole thing (or whatever’s specified in your write node). The -xi just uses the correct license server.

Finally, –gpu is what does the trick, in allowing you to use the power of your GPU to render. You can make sure your GPU is set up in Nuke by typing the following command: nuke –gpulist

If you wanna change your GPU, open the actual Nuke app, and go to Preferences > Performance > Hardware. Select the GPU you wish to use from the dropdown menu.

Note: if you have multiple Write nodes in the comp, this terminal command will render all of them out at the same time. This can be extremely useful if you wanna export multiple passes for your VFX, if you plan to do a final color correction pass in, say, After Effects.

Badabing badaboom!

Hope this helps. Have fun!