V-Ray Tip: V-Ray Lightmap Baking Best Practices for Real-Time Engines

Baking lightmaps in V-Ray bridges offline-quality lighting with real-time performance, ideal for VR, AR, and interactive apps.

Why bake:

• Massive performance gains in engines by precomputing diffuse GI and soft shadows.
• Consistent, filmic lighting look without expensive runtime calculations.
• Deterministic results that travel cleanly across platforms.

Prepare your assets

• Separate static from dynamic objects. Bake only static geometry; keep moving/animated items unbaked.
• Create a dedicated lightmap UV set (typically UV2): non-overlapping, uniform texel density, and margins intact. Avoid UDIMs for lightmaps—most real-time engines require a single UV tile.
• Set texel density targets:
  • Mobile/low-spec: 64–128 px/m
  • General real-time: 256–512 px/m
  • Hero/close-up props: 1024+ px/m (selectively)
• Ensure thin surfaces are two-sided where needed to avoid GI leaks, or thicken geometry slightly.

Lighting and materials

• Light with physically plausible sources (Dome + HDRI, Sun/Sky, IES). Keep intensities in real-world units.
• Minimize fully glossy or refractive contributions in the bake if your engine will handle those in real time (bake predominantly diffuse/GI).
• Reduce emissive objects with extreme intensity—emissive noise is costly to clean in lightmaps.

Render settings for reliable bakes

• GI: Brute Force (primary) + Light Cache (secondary) for robust indirect lighting.
• Noise threshold: 0.005–0.01 for stable, denoise-friendly results.
• Denoiser: Use Intel Open Image Denoise (CPU) or NVIDIA (GPU) after reaching a reasonable noise level to avoid blurring detail.
• Color pipeline: Bake in linear space. Disable VFB color corrections/tone mapping and LUTs—bakes should be un-tonemapped lighting.
• Output: 16-bit half EXR preferred during authoring; convert to the engine’s required format on export if needed.
• Padding/gutter: 8–32 px or 1–2% of texture size to prevent seams under mipmapping.

What to bake

• One-map workflow: VRayComplete-style bake for simplicity (albedo × lighting baked together), suitable for fixed looks.
• Layered workflow: Bake Lighting or Indirect only, plus optional AO and Emission. Multiply in-engine over base color to allow dynamic direct lights and more flexible art direction.

Engine import tips

• Mark lightmaps as linear/non-color in the engine (disable sRGB on import for Unity; ensure correct compression where supported).
• Verify that materials use the intended blend (Multiply for indirect or combined lighting maps).
• Check seams at grazing angles; if visible, increase padding or even out texel density.

Troubleshooting and iteration

• Leaking/light bleeding: Fix open edges, add light blockers, or reduce GI bounces for problem assets.
• Noise: Increase GI quality modestly and rely on denoising; don’t overshoot subdivs.
• Hot pixels/fireflies: Lower overly intense emissives; clamp direct light contributions if needed; ensure proper importance sampling on textured lights.

Automate bakes with your host’s Render/Bake to Texture and consistent naming. Document texel targets and UV conventions so teams can reproduce results. For licensing, upgrades, and expert guidance on V-Ray across DCCs, consider NOVEDGE. You can also explore Chaos products and workflow solutions via NOVEDGE to keep your real-time pipeline efficient and predictable.