V-Ray Tip: V-Ray Sampler Tuning: Progressive vs Bucket

Quick guidance to choose and tune Progressive vs Bucket in V-Ray for maximum throughput and predictable quality.

Choose the right mode

• Progressive: Best for look development, lighting/material iteration, and interactive feedback. It converges uniformly across the frame and can be time-capped.
• Bucket: Best for finals, high-resolution stills, predictable memory usage, and efficient distributed rendering across multiple nodes.
• Rule of thumb: Iterate in Progressive; lock comps and render finals in Bucket. Validate both on a small test frame before committing.

Progressive sampler: fast iteration settings

• Noise threshold: 0.02–0.01 for look-dev; tighten to 0.007–0.005 when you’re close to final. Stop by time when speed matters more than residual noise.
• Max render time: Enforce budgets (e.g., 2–5 minutes during look-dev) to maintain cadence.
• Min shading rate: Increase (6–8) for scenes with strong DOF/motion blur or crisp edges; lower (2–4) for GI/SSS/volumetrics to push more rays into shading.
• Denoiser: Use NVIDIA/Intel in the VFB for previews; switch to the V-Ray denoiser for finals or export denoising AOVs for comp.
• Animation: Enable locking of the noise pattern to minimize temporal crawl; validate with short ranges.

Bucket sampler: final-frame control

• Noise threshold: 0.005–0.003 for print and hero frames; relax slightly for web/video.
• Max subdivs: Avoid excessive values; start ~24–32 and nudge only if the sampler can’t reach the threshold.
• Bucket size (CPU): 32–48 px for heavy displacement/volumes (reduces peak RAM); 48–64 px for modern multi-core CPUs for better throughput.
• Distributed rendering: Buckets map cleanly to nodes; ensure assets are centralized/accessible to avoid stalls. For help with node licensing and setup, check NOVEDGE.

GI and caches (applies to both)

• Precompute caches (e.g., Light Cache) once for finals; reuse across cameras where possible.
• For animations, prefer stable GI strategies (e.g., Brute Force + Light Cache with consistent settings) to reduce flicker.

Noise, fireflies, and hot pixels

• Specular-intensive scenes: Use reasonable highlight sizes, properly calibrated HDRIs, and avoid tiny, ultra-bright emitters.
• Clamp max ray intensity to tame fireflies (e.g., 2–10); document any clamping for energy-critical shots.
• Texture filtering and slightly higher roughness often reduce persistent sparkle without heavy sampling cost.

Workflow tips that save hours

• Match thresholds: Find a tolerable Progressive noise level/time, then switch to Bucket with the same target threshold for finals.
• Use region/cryptomatte/LightMix to localize fixes instead of full re-renders.
• Profile first frames with the V-Ray profiler to identify dominant costs (GI, reflection, refraction) and adjust materials/lights accordingly.
• Audit textures: oversized maps penalize both modes. Optimize resolution and compression early.

Need guidance on sizing render nodes, mixing CPU/GPU, or license bundles? The team at NOVEDGE can help tailor a V-Ray setup for your studio. Explore current V-Ray options and add-ons at NOVEDGE.