V-Ray 3.3 for 3ds Max Review by Hammer Chen

Chaos Group has unveiled V-Ray v3.30 for 3ds Max 2009 - 2016 last month and We're lucky enough to have the review article by our ...

Chaos Group has unveiled V-Ray v3.30 for 3ds Max 2009 - 2016 last month and We're lucky enough to have the review article by our great friend Hammer Chen
(Robot spider 3D model kindly provided from Lien Ying-Te)

Pros

• VrayTriplanarTex is able to produce triplanar mapping of any other 2D texture over an object that doesn't have UV coordinates. This feature has great potential. Combined with VRayCuravature is perfect for geometry sensitive mask ─ which is the key element for realistic material.
• V-Ray 3.3 delivers simplified workflow: artist now can focus on only two parameters: "Max AA Subdivs" and "Noise Threshold / Color Threshold". For team work or large projects,  inevitably scene assets accumulate different material / light subdivision. SP3 disregards all individual shading subdivs. Even for Xref scenes, the subdivs are calculated at render time. There's no need to adjust anything for xref. This is one important step for large scale automatic production.
• Under strict linear workflow, without help of "sub-pixel mapping" or "Clamp Output" new V-Ray cure fireflies artifact automatically.
• Predictable image quality. A linear relationship between the noise / color threshold value and the render time. 
• With similar image noise level, SP3 reduce rendering time by 29%.
• "Compare V-Ray Settings" is a handy tool for comparing settings differences between images.
• Faster volume rendering with "probabilistic shading", reduced render time by 47% and remove white spot noise
• Hosek Sky Model simulate more realistic sky
• Aerial perspective for efficient and realistic atmospheric depth
• V-Ray Clipper supports cutaways using any arbitrary mesh at render time

Cons

• With same Noise Threshold / Color Threshold value, in this specific scene, SP3 take more time to render (However SP3 effectively suppress fireflies artifact)
• Users need to refrain from tweaking, get rid of old habits and give V-Ray a chance to work as it should.
• Inconsistency in naming the same parameter for the adaptive and progressive AA modes.

Chaos Group has released update to V-Ray for 3ds Max in December last year. Before Vlado has been released some new features such as VRayTriplanarTex, Stochastic Flakes. This official release include those two plugins. According to the official showcase video V-Ray have significant improvements in speed and function wise. Let's look at the actual tests:

Variance-based adaptive sampling (VBAS)
Although VBAS is a new feature,  it can not be found in the UI nor drop-down menu. This is the warning message when we open old V-Ray scene files win new SP3:

If you choose YES, your scene may render slightly different, may need some fine-tuning. Choosing "NO" your scene will render same as previous version. For optimized performance, reset your render settings by setting to default scanline and set back to V-Ray renderer. By doing this you can have a clean default settings. Choosing "YES" actually change many parameters that scattering throughout the UI. As describe on this thread of Chaos Group forum: "Old 3.2 / new 3.3 behavior switcher", you are able to switch between the old settings and new one by runing a maxscript. The following are the script for V-Ray 3.3 ( two level adaptive, sRGB color space and dynNoiseThreshold  can not be found in the UI)

The following are the script for V-Ray 3.2 behavior:

Therefore, when we choose YES means:

• "Use Local Subdivision" is off. V-Ray disregards all individual shading subdivs. You have only one shading quality control - "min shading rate".
• "Reflective GI Caustics" is on. Since SP3 robust handling of reflective GI caustics, this is basically a free effect. Your interior scene might looks brighter and more realistic.
• "Min Shading Rate" is set at 6. This is best value based on statistics from Chaso group.
• Color Space set to sRGB. The conversion avoid extreme RGB values internally. sRGB allows faster render speed and more realistic image.

Now we know that changing of new settings, we can start our benchmark test. You can find a clear guideline in this thread "Cheatsheet: How to get a Cleaner image with SP3", we can focus on two parameters:

1. Max AA Subdivs 
2. Noise Threshold/Color Threshold

To make the procedure even more simpler, I only change "color threshold" in this case. Here are my test results when rendering with V-Ray 3.3 new settings:

Here are my test results when rendering with old settings:

As you can see, with same Color threshold, in this specific scene, V-Ray 3.3 increase rendering time by 42 ~ 248%. However, with same value of Color threshold, SP3 produce much less noise and more even noise levels across the image. Obviously the meaning of Color threshold / Noise threshold is different between new and old settings.

V-Ray 3.2 (left) shows more white noise than V-Ray 3.3 (right) in the dark area. 

Based on initial test results, I found with Color threshold = 0.15,  I can get good noise level within a reasonable time. The upper image shows the V-Ray 3.2, Color Threshold = 0.05; lower image shows V-Ray3.3, Color Threshold = 0.15. Therefore, with similar image noise level, V-Ray3.3 reduce  rendering time by 29%.

New Sky Model

From top to bottom, rendered with CIE, Preetham and Hosek sky model. The new sky model Hosek simulate more natural sky.

Hosek Sky Model ＋ V-Ray frame buffer / Lens Effcet

Aerial Perspective

This is the new Environment / Effect, produce efficient and realistic atmospheric depth

With "affect environment rays" ticked, simulate light scattering effect.

Triplanar Mapping

A long waiting new feature. The is one of my favorite new feature of SP3. A quote from well known artist Neil Blevins' Blog:

"I can't believe it, I've been bugging various developers for well over a decade for this, and now the time has finally arrived! Vlado did it, he finished the Blended Box Map Plugin!"

Even with seamless textures, you can still see seams when apply to 3D model. With VrayTriplanarTex , even when object don't have proper UVW, you can have any 2D texture map cover the surface. The blend control reduce seams dramatically.

Combined with VRayCurvature, you can easily create a geometry-sensitive mask by mixing the two. Such mask is the key element to realistic materials, rusted metal for example. 

Here is the video demonstration of the entire process:

V-Ray Clipper

Improved V-Ray Clipper with Render-Time Booleans, supports cutaways using any arbitrary mesh

Stochastic Flakes

Uses less memory, completely avoids tiling artifacts and produces more realistic results

Volume rendering / Probabilistic Shading

Here I use FumeFX to simulate the explosion, output the cache sequence as Field3D. This open format can be read by VRayVolumeGrid.  With "Probabilistic Shading" checked render faster (from 1m 18s , down to 41s, reduce rendering time by 47%)

Reduce white spot noise when Probabilistic Shading ticked.

PhoenixFD Ocean + Aerial Perspective + Hosek Sky + VRayTriplanarTex + Probabilistic Shading

Compare V-Ray Settings

This shows a table with the differences between the settings used to render the selected image and ones currently set in the V-Ray renderer. A perfect tools for optimize render settings.

Save / load LUT file

Ray Traced Rounded Corners

Create rounded edge in render time, a good feature for interior design as it give hightlight for hard corner. 

Other new features:

• GI: More robust handling of reflective GI caustics, better light propagation, and more natural illumination of interior scenes. Distributed light cache for faster calculations with distributed rendering
• GPU rendering: More texture nodes – MultiTexture, VRayMultiSubTex, ColorCorrection etc. Proxy objects with hair and particles VRayFur and VRayPlane objects Light include/exclude lists
• Progressive Sampler:  Dynamic noise threshold leads to more uniform noise distribution. Improved sub-pixel filtering. Improved CPU utilization
• Geometry: Faster rendering of proxy objects and instances. Faster rendering with Forest Pack Pro

Conclusion:
V-Ray 3.3 provides designers a simplified workflow, so you can spend less time adjusting parameters. VrayTriplanarTex has great potential for daily use. In fact, it is one of the major reason you should upgrade to SP3. ChaosGroup development team not only focus on rendering speed, but also make V-Ray versatile. For example, V-Ray support Field3D open source voxel format, and accelerate rendering through Probabilistic Shading. As an FX artist and TD, I believe this is why V-Ray can maintain as leading brand in this competitive market. Since version 3.0, V-Ray simplified it's user interface. In this service pack, V-Ray allow users focus on only two parameters. Perhaps in the near future , the entire interface will become one simple render button, allowing artists to work creatively. Happy rendering : )

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