In brief
- Halving the noise threshold doubles render time; 0.01 + a denoiser is enough for most interiors as a final render.
- For GI, Brute force + Light cache (Subdivs 1000, Retrace 2.0) is Chaos’s recommended combination for still images.
- In scenes with many spotlights, Global switches › Light evaluation › Adaptive lights reduces shading costs.
- With VRayDenoiser, the Default engine is consistent across render elements; NVIDIA AI is fast but not suited to animation.
This guide is for V-Ray 7 for 3ds Max, including Update 4, released in August 2026. Almost all the settings described here are in the same places in V-Ray 6. Our goal is to cut render times without sacrificing quality in a typical interior scene combining daylight and artificial lighting.
First, it’s important to understand this principle: in V-Ray, sample count is the main factor determining render time. Whatever setting you change, you’re ultimately either reducing the number of rays cast per pixel or distributing those rays more intelligently. The seven settings below do one or the other.
1. Choose the right sampler: Bucket or Progressive?
Menu path: Render Setup › V-Ray › Image sampler (Antialiasing) › Type
Progressive: The entire image gets a little cleaner with each pass. It’s useful when testing lights and materials because you can stop the render whenever you like or set a time limit.
Bucket: Completes the image in regions. Chaos recommends Bucket for final renders in its interior rendering guide. It generally uses less RAM and reduces network traffic in distributed rendering (DR).
In practice, work with Progressive while setting up lights, then use Bucket for the final output. Since both modes use noise thresholds in the same way, switching between them won’t compromise the result.
2. Noise threshold: the biggest time savings start here
Menu path: Render Setup › V-Ray › Bucket image sampler › Noise threshold
This value is the threshold V-Ray uses to decide whether to cast more samples for a pixel. Here are the steps listed on Chaos’s interior rendering settings page:
| Use | Noise threshold | Effect |
|---|---|---|
| Quick preview | 0.1 | Very fast, visibly grainy image |
| Quick check | 0.05 | Composition and lighting balance are easy to assess |
| High-quality preview | 0.01 | A draft you can send to a client |
| Final render (without denoiser) | 0.005 | Very little noise, longest render time |
The same document also states the most important rule: Halving the noise threshold doubles render time. So increasing it from 0.005 to 0.01 roughly halves render time. A denoiser can easily make up the difference (see step 6).
3. Don’t adjust Min / Max subdivs unnecessarily
The same panel contains Min subdivs and Max subdivs. The actual sample count is the square of these values (4 subdivs = 16 samples).
Min subdivs: According to Chaos documentation, it rarely needs to be above 1. Leave it at 1 unless you have fine details (for example, sheer curtains or thin railings) or motion blur.
Max subdivs: The default is 24. This is a ceiling. V-Ray only goes up to this value for pixels where noise remains above the threshold.
A common mistake is lowering Max subdivs to 8 because a render is taking too long. This can stop sampling in noisy areas (dark corners, matte reflections) before the threshold is reached. Use noise threshold first to control render time.
4. GI engine: Brute force + Light cache
Menu path: Render Setup › GI › Global illumination › Primary engine / Secondary engine
In most cases, Chaos recommends Primary: Brute force, Secondary: Light cache as the best quality-to-speed combination. Light cache precomputes and caches secondary bounces in interiors where light bounces many times. This means brute force doesn’t have to trace rays from scratch for every bounce.
Light cache settings (GI › Light cache):
| Setting | Value | Effect |
|---|---|---|
| Subdivs | 1000 (default) | Number of paths traced from the camera (squared); sufficient for still images |
| Retrace | 2.0 (still image) | Retraces GI at corners; reduces light leaks |
| Subdivs / Retrace (animation) | 3000 / 8 | Chaos’s recommendation for animation to prevent flickering |
For a still image, increasing Subdivs to 3000 generally makes no visible difference, but extends precomputation time.
5. For scenes with lots of spotlights: Light evaluation
Menu path: Render Setup › V-Ray › Global switches (visible in Advanced mode) › Light evaluation
In hotel lobbies or retail scenes with dozens of spotlights in a suspended ceiling, having V-Ray evaluate every light at every shading point (Full lights evaluation) can be very expensive. There are two alternatives:
Adaptive lights: Uses Light cache information to decide which lights to sample. The Number of lights value should be lower than the actual number of lights in the scene; otherwise, there’s no benefit. Lowering the value speeds up rendering but can increase noise.
Light tree: Selects light sources based on proximity. If Light cache isn’t being used, adaptive sampling also uses this method.
This setting has a limited effect in simple scenes with only a few lights. The benefits become more noticeable as the number of lights increases.
6. Use the right engine for V-Ray Denoiser
Menu path: Render Setup › Render Elements › Add › VRayDenoiser
The denoiser runs as a separate process after rendering is complete. You don’t need to render the scene again to change the setting and clean up the image. There are three engines:
| Engine | When to use it | Notes |
|---|---|---|
| Default V-Ray denoiser | Final image, compositing with render elements, animation | Accelerated on CPU or GPU; consistent across render elements |
| NVIDIA AI denoiser | Quick drafts, interactive rendering | Requires an NVIDIA graphics card, is inconsistent across render elements, and isn’t suitable for animation |
| Intel Open Image Denoise | High-quality denoising independent of hardware | Uses an NVIDIA GPU if available; otherwise, falls back to the CPU |
The Default engine’s presets are Mild (Strength 0.5, Radius 5), Default (1 / 10), and Strong (2 / 15). For interiors where wood grain and fabric texture need to be preserved, start with Mild. Chaos notes that very noisy images can produce artifacts and recommends keeping the noise threshold at 0.05 or below when using a denoiser. For blending frames in animations, Chaos recommends the standalone vdenoise tool.
7. Test lighting without materials
Menu path: Render Setup › V-Ray › Global switches › Override mtl
Assign a single gray material to the whole scene while balancing the lighting. Chaos recommends a default VRayMtl with a Diffuse color of RGB 200,200,200. With glass, highly reflective floors, and dense texture maps out of the way, test renders become significantly faster. You can also assess lighting ratios independently of material colors. Keep the resolution low at this stage, too (Chaos recommends 640×480 for initial tests). Remember to turn off Override mtl before rendering the final output.
Extra tip: Firefly removal in the Bucket sampler cleans up isolated bright pixels. Its effect increases with the value, but it can also remove real detail. It currently works only with CPU rendering.
Before / after: What changes?
When you switch from a setup close to the defaults with “everything high” (Noise threshold 0.005, no denoiser, Full lights evaluation, lighting tests with full materials) to the setup above, here’s what typically happens:
Noise threshold 0.005 → 0.01 + Default denoiser (Mild): Based on Chaos’s rule about halving the threshold, sampling time roughly halves. The denoiser cleans up the remaining slight noise.
Adaptive lights in a scene with many spotlights: Shading costs drop noticeably as the number of lights increases. The gains depend on the scene, so be sure to measure them in your own scene.
Lighting tests with Override mtl: Test iterations are shorter, and lighting decisions become clear sooner.
The best way to measure the gains is to render twice with the same camera and resolution, then compare the render times in the V-Ray Frame Buffer. Change only one setting at a time, or you won’t know which one made a difference.
Quick checklist
While setting up lights, use Progressive + Override mtl + a low resolution.
For the final render, use Bucket + Noise threshold 0.01 + VRayDenoiser (Default engine, Mild).
Use Brute force + Light cache for GI; Retrace 2.0 is sufficient for still images.
If the scene has many lights, try Adaptive lights in Global switches.
Adjust noise threshold instead of lowering Max subdivs.
Sources
4 sourcesSource texts are not republished; short quotes are marked, everything else is our own summary and commentary.
The most common mistake we see in offices is using “ultra” presets found online: Noise threshold 0.001, Max subdivs 50, Light cache 5000. An interior rendered with these settings takes several times longer than one rendered with 0.01 + a denoiser. The difference is often indistinguishable even in an A3 print. If a project has 10–15 cameras, that one decision can save a night on the delivery deadline.
On the hardware side, V-Ray CPU rendering scales almost linearly with the number of cores. NVIDIA AI denoiser requires an NVIDIA graphics card. If you don’t have one, Intel Open Image Denoise also runs on the CPU. If you use distributed rendering (DR), the Bucket sampler has the added benefit of reducing network traffic. Try these settings before buying a new machine: the bottleneck is often the preset, not the hardware.
Frequently asked questions
What should the noise threshold be in V-Ray?
Chaos’s recommendations for interiors are: 0.1 for quick previews, 0.05 for quick checks, 0.01 for high-quality previews, and 0.005 for final renders without a denoiser. If you’re using a denoiser, 0.01 is sufficient for most scenes. Chaos recommends keeping the threshold at or below 0.05 when using a denoiser.
Should I use Bucket or Progressive in V-Ray?
Progressive is convenient for testing lights and materials because you can stop it whenever you like. For final renders, Bucket generally uses less RAM and reduces network traffic in distributed rendering.
Does V-Ray Denoiser cause flickering in animation?
NVIDIA AI denoiser isn’t suitable for animation because it doesn’t blend between frames. For animation, the recommended approach is to use the Default V-Ray denoiser and V-Ray’s standalone vdenoise tool.
