If TouchDesigner is giving an “Invalid Filename” error when trying to save a PNG sequence, here are the correct steps to ensure your filename format works properly:
Instead of $F (which sometimes doesn’t work in file paths), use frame number formatting specific to TouchDesigner:
Use:
or
🔹 Explanation:
#### is a placeholder that will be automatically replaced by the frame number (e.g., image_name.0001.png).
- The dot (
.) before the frame number is required in some cases.
If you’re using a Movie File Out TOP:
- Set “File Type” → “Image Sequence (.png)”
- In “Filename” field, enter:
C:/my_renders/image_name.####.png
- Frame Padding: Adjust padding under Movie File Out TOP settings.
If you need a more manual approach (e.g., scripting):
op('moviefileout1').par.file = "C:/my_renders/image_name.{:04d}.png".format(int(me.time.frame))
🔹 This ensures filenames like:
If you still get an “Invalid Filename” error:
✅ Check Your Save Location: Avoid saving to system-protected folders (e.g., C:/Program Files).
✅ Ensure the Movie File Out TOP is Active: Start rendering before checking file output.
✅ Try Using an Absolute Path: Specify the full save location.
C:/my_renders/image_name.0001.png
C:/my_renders/image_name.0002.png
C:/my_renders/image_name.0003.png
This should prevent overwriting and work smoothly in TouchDesigner. Let me know if you need more help! 🚀