VST3 version of Pro-L 2 is missing parameters

Renoise Tool Development
1

When enumerating the parameters of FabFilter Pro-L 2, the number of parameters differ between the VST and VST3 version of the plugin. Here are the parameters from the VST version:

  1. Gain
  2. Style
  3. Lookahead
  4. Attack
  5. Release
  6. Channel Link Transients
  7. Channel Link Release
  8. Channel Link Center
  9. Channel Link LFE
  10. Oversampling
  11. True Peak Limiting
  12. Dithering
  13. Noise Shaping
  14. Filter DC Offset
  15. Side Chain Triggering
  16. Unity Gain
  17. Audition Limiting
  18. Bypass
  19. Output Level
  20. Lock Output
  21. Receive Midi
  22. Show Advanced
  23. True Peak Metering
  24. Display Mode
  25. Meter Scale
  26. Loudness Time Scale
  27. Loudness Meter Scale
  28. Loudness Meter Origin
  29. Loudness Meter Target
  30. Loudness Integrated Peak Time Scale
  31. Loudness Recording
  32. Loudness Auto-Reset

And here are the parameters from the VST3 version:

  1. Gain
  2. Lookahead
  3. Attack
  4. Release
  5. Channel Link Transients
  6. Channel Link Release
  7. Channel Link Center
  8. Channel Link LFE
  9. Dithering
  10. Noise Shaping
  11. Filter DC Offset
  12. Side Chain Triggering
  13. Bypass
  14. Output Level
  15. Receive Midi

Does anyone know what causes this discrepancy?

2

This is usually not Renoise dropping anything - VST2 and VST3 are separate parameter definitions in the plugin itself, and vendors often expose a reduced or renamed set in the VST3 build. FabFilter in particular hides some parameters from host automation in VST3 (Bypass and a few link/dither options are commonly handled differently, since VST3 has a dedicated bypass concept rather than a normal parameter). So the missing entries are almost certainly not automatable in the VST3 build at all, not a broken enumeration on your side. Worth confirming by loading the same VST3 in another host and dumping its parameter list - if you get the same count there, it’s the plugin’s design. If you need those specific parameters for a tool, the practical answer is to target the VST2 build, or drive the plugin over MIDI CC if FabFilter maps them. It may also be worth asking FabFilter directly; they’ve been fairly straight about which parameters they intentionally omit from VST3.