V-Ray Tip: Export V-Ray Frame Buffer LUTs for Pipeline Color Consistency

When your look is dialed in the V-Ray Frame Buffer, export a LUT so every shot in your pipeline matches it—on any machine, in any DCC.

Quick workflow (VFB):

• Finish your look in the VFB Layers (Exposure, Curves, Filmic, Color Balance, Hue/Sat, etc.). Keep Lens Effects (Bloom/Glare) off—they’re not LUT-able.
• Confirm color management:
  • If using ACES: Load your OCIO config in VFB and choose the proper View/Display (e.g., ACES 1.3, ACEScg → sRGB).
  • If using sRGB/linear: Ensure VFB is in linear workflow with a consistent display transform.
• Export the LUT:
  • From the VFB color corrections menu, choose Export/Save LUT (.cube). For internal reuse in VFB, also save a preset (.vccgl).
  • Cube size: 33 is a good default; 64 improves smoothness on subtle gradients (skin, skies) at a small performance cost.
  • Pick the correct input color space for the LUT (ACEScg or linear sRGB) to match where it will be applied in comp.
• Validate: Load the .cube in the target app (Nuke, Resolve, After Effects) and compare against the VFB using the same display/view transform.

Where to apply the LUT:

• Scene-referred (recommended for ACES): Apply the LUT to linear ACEScg data before the View/Display transform. This preserves HDR headroom for grading.
• Display-referred (preview LUT): If you explicitly baked a display transform, apply the LUT after conversion to display space; use only for client previews, not final grading.

Best practices:

• Stick to LUT-friendly layers: Exposure, White Balance, Filmic, Curves, Color Balance, Hue/Sat. Avoid Bloom, Glare, Sharpen/Blur, Vignette—export won’t include them.
• Keep HDR unclamped in renders; let the LUT and view transform handle tone mapping.
• Version everything: Name LUTs with show/shot/look, color space, and date (e.g., SHOWA_LookDev01_ACEScg_2026-06-15.cube).
• Lock your OCIO config version with the project and stash it alongside the LUT for reproducibility.
• QA with a color chart and grayscale ramp to catch banding or gamut clipping.

Troubleshooting:

• Mismatch vs. VFB: Verify the same View/Display transform is used in both VFB and your comp app. Check that you’re applying the LUT in the intended domain (scene- or display-referred).
• Banding: Increase cube size to 64 or simplify extreme S-curve shaping. Ensure 16/32-bit processing in the host app.
• Crushed highlights: Confirm you didn’t clamp Max Ray Intensity too aggressively; re-render or reduce highlight-compress steps in the look.
• Wrong saturation: Double-check working and LUT input color spaces (ACEScg vs. linear sRGB).

Pipeline tips:

• Distribute the LUT and a short “how-to-apply” note to lighting, comp, and editorial.
• Automate loading the LUT in your render template or comp gizmos to prevent drift.

Upgrading V-Ray or standardizing teams? Consult NOVEDGE for licensing and pipeline planning: NOVEDGE. For multi-app ecosystems (3ds Max, Maya, SketchUp, Rhino), align color management and LUT deployment across seats—your partners at NOVEDGE can help you design a consistent rollout.