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The VRayScannedMtl material applies material information gathered by the Chaos Group VRscans system to an object. The VRscans system captures the appearance of an actual physical material sample, going beyond single-point BRDF capture to faithfully represent the textured appearance of a real-world surface using bidirectional texture function (BTF) approximation. The information is saved in a .vrscan file, which the VRayScannedMtl material then reads to reproduce the material in the rendering.

The VRscans system and VRayScannedMtl material are intended as a solution for users who need to exactly match a given real-world sample.

Note

The VRayScannedMtl material is designed to be used with a licensed version of the VRscans software. The material will still render without a license, but the material's UI will not display and any renderings will include a watermark.

The scanned material simply stores information about the way a physical material responds to light at individual points on the surface; it has no notion of components that extend across the surface such as diffuse or reflection qualities, or normal or bump maps. The scanned material is simply a faithful representation of how each point on the object responds to light. The .vrscan files tend to be quite large.

Currently, the material can render opaque and transparent surfaces. Also, aside from some general tint control, the material is unmodifiable; you can't change glossiness, increase reflectivity etc. You can only change the overall tint of the material.

For more details on VRscans, please see the VRscans documentation for information on downloadable sample scenes and Frequently Asked Questions, or visit the VRscans.com website.

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Subdivisions – Controls how many reflection rays will be traced for the material. Note that the material does not have a diffuse or reflection component , and that everything is considered glossy reflection.

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None – Used to view the material as it is with all the maps.
Average BRDF – Averages the BRDF and can be used to speed up the rendering for previews. Because texture details are removed, this also removes any tiling artifacts that might arise if the scanned sample does not tile very well. UV coordinates are still needed because most BRDFs are slightly anisotropic.
Average isotropic BRDF – Smooth representaion representation of the material with no maps visible.
Scramble – Uses blocks from the photo samples in the material. Useful to reduce tiling artifacts for isotropic materials with small details like car paint with flakes.

Color space – Specifies between sRGB, Adobe RGB, and Pro Photo color space models.

Don't use GI for primary rays – GI caches will only contribute to indirect rays. By default, this option is enabled (i.e. GI is not used for primary rays) to ensure better realism of materials. It makes sense to disable this option when the scene lighting is relatively even from all directions, as it will speed up the rendering but will likely cause no loss of image quality.

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This is a standard 3ds Max rollout used to control how the material is applied to objects.

 

Material Optimization

When using this material, there are certain settings that can optimize quality and rendering time.

Antialiasing Settings

The easiest way to optimize antialiasing is to use the Progressive Image Sampler. This approach can be a little bit slower but it doesn’t require complete understanding of the sampling in V-Ray and will work for any scene. The settings to use in the 3ds Max Render Setup window are:

Sampler type: Progressive
Min Shading Rate:
1
AA filter:
Enabled
AA filter type:
Lanczos
Size:
2.5
Min subdivs:
1
Max subdivs:
200
Noise threshold:
0.01
Max. render time (min):
Set this value to the maximum render time you would like to use.

 

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Using the Adaptive image sampler can sometimes produce the same result in slightly faster render times, but it requires that you experiment with different settings and have a good understanding of how sampling works inside V-Ray.

A good starting point for high quality rendering is:

Sampler type: Adaptive
Min Shading Rate:
1
AA filter:
Enabled
AA filter type:
Lanczos
Size:
2.5
Min subdivs:
1
Max subdivs:
33
Threshold:
0.01

 

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For darker images you may need to slightly increase the Min Subdivs up to 4. To further increase the quality, you need to first start by slightly decreasing the Threshold and then increasing the Max subdivs in small steps one after the other.

For a quick render to assess quality use the following settings for the Adaptive Sampler:

Min subdivs: 1
Max subdivs:
11
Threshold:
0.03

 

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Global Illumination

The V-Ray Scanned material is a purely reflective material (it doesn’t have a diffuse component). This means that for scenes that are comprised of V-Ray Scanned materials entirely you do not need to enable GI.

If you still want to use global illumination, use the settings below in the Global Illumination rollout:

Primary Bounce (Primary engine): Brute Force – use the default settings for Brute Force
Secondary Bounce: (Secondary engine)
Light Cache
Subdivs
: 2000 for simpler exterior scenes and 4000 for interior scenes where light bounces a lot
Sample Size
: 0.02
Store Direct Light:
Enabled
Use light cache for glossy rays (Use for glossy rays):
Enabled
Filter type (Filter):
None
Prefilter:
Enabled
Prefilter samples:
10
Depth (Bounces):
10
Use retrace threshold (Use for glossy rays):
Disabled

 

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Scanned Material Options

The V-Ray Scanned Material options should rarely be adjusted beyond the following values:

Subdivisions: 8
Trace Depth
: 5
Cut off:
0.01
Retrace (Don’t use GI for rays shorter than):
0
Displacement (Edges Displacement):
 Only enable when there are close-ups of materials with bumps.
No Prim GI (Don’t use GI for primary rays):
Enabled

 

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