This page provides information on the V-Ray Scanned material.
The V-Ray Scanned 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 V-Ray Scanned material then reads to reproduce the material in the rendering.
The VRscans system and V-Ray Scanned material are intended as a solution for users who need to exactly match a given real-world sample.
V-Ray Scanned requires a separate VRscans license. The material will still render without a license, but it will include a watermark and the material's UI will not display.
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.
UI Path: |Shading viewport| > Shader Tree > Add Layer button > V-Ray Materials > V-Ray Scanned
File – Browses for a .vrscan file on your local drive.
Reset channel values to .vrscan preset – For each selected V-Ray Scanned material item, this button will reset some of its channels according to the data in the .vrscan file chosen for it.
Show .vrscan material info – Displays useful information about the specific .vrscan file, such as the actual material sample size.
Adjust UV tiling to match real-world size – Clicking this button will examine all selected polygons on selected meshes to determine the real-world size of one texture unit. After that, it will adjust the Horizontal Wrap and Vertical Wrap channels on the texture locators of all selected V-Ray Scanned materials, according to the texture unit size and the size of the .vrscan sample.
Tiling Factor – Global multiplier for the U and V coordinates.
Create OpenGL Preview – Creates an OpenGL preview of the material within the viewport.
Preview Size – Adjusts the size of the OpenGL preview of the material.
Use Filter – Enables the use of the color filter.
Filter Strength – Multiplies the effect of the filter.
Filter Color – A color multiplier for the material sample that can be used to tint the material (it will affect the color of the reflections as well. Acts as a post effect.)
Use Paint – Enables the use of Paint Color.
Paint Strength – Multiplies the effect of the paint.
Paint replacement color – Used to change the color of the material without losing the texture or changing the reflection color. For example, it can be used to changing the color of wood or leather without losing the material texture.
Gamma Correction – Adjusts the gamma of the material (including Filter Color and Paint Color if used) as a post effect.
Saturation – Controls the saturation of the material (including Filter Color and Paint Color if used) as a post effect.
Two Sided – Enables both sides of the material.
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. Note that this parameter is available for changing only when Use Local Subdivs is enabled in the DMC Sampler Settings.
Transparency – When disabled, transparent properties of the material will not be rendered.
Trace Depth – Controls the number of reflection bounces. A value of 0 means that the reflections bounces are controlled by the global V-Ray trace depth in the of V-Ray's Main Render Settings.
Cutoff – A threshold that is used to speed up reflections. If the contribution of reflections falls below this threshold, the reflections are not traced. This is similar to the Cutoff threshold of the V-Ray Material.
Sampling Type – Determines which samples are taken around pixels involved in "blurry" effects such as anti-aliasing, depth of field, indirect illumination, area lights, glossy reflections/refractions, translucency, motion blur, etc.
Importance sampling – Bases the number of samples allocated to a value on the importance when it comes to things like distance from the camera or if more samples are needed to render a realistic result.
Uniform sampling – The number of samples is the evenly taken over the entire image.
Plain Materials – A strategy used for material display. It controls the visibility of textures (if present). Possible values are:
Disabled – The full material evaluation is always used. The object must have valid UV coordinates.
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 representation of the material with no maps visible.
Color Space – Choose between sRGB, Adobe RGB, and Pro Photo color space models.
Displace – Uses a special technique that makes the edges of the geometry appear slightly jagged inwards. This option is useful when rendering close-ups of materials with bumps. It is faster than actual displacement and helps to achieve better realism.
Don't Use Cached Light – Disables the cached light for the material, ensuring physical accuracy without the need to switch off GI of the entire scene. Disabling this option results in faster, but less physically accurate render.
Enable Clear Coat – Enables the tracing of a clear coat layer for the material.
Enable Clear Coat Highlights – Enables highlights from point light sources for the coat layer.
Index of Refraction – Determines the IOR of the coat layer, and from that controls the strength of the reflections. A value of 1.0 does not produce any reflections and disables the coat layer. Higher values produce stronger clear coat reflections. The .vrscan files typically contain the correct value for this parameter and it is set automatically when the file is loaded.
Bump multiplier – The coat layer has a built-in bump map stored in the material sample file. This allows you to control the strength of that bump.
The options in this section are not intended for regular users. Manipulating them comes at your own discretion.
The V-Ray GPU render engine supports V-Ray Scanned with few exceptions. In general, if your renderer is set to V-Ray GPU, all unsupported features will be grayed out.
- Paint and Filter don't support texture maps;
- Fast Volumetric Transparency is not supported;
- Cutoff parameter is not supported.
V-Ray Scanned can make use of some of the Render Elements. Here is a list of those elements:
- Clear coat reflections stored in the Reflection Render Element;
- Direct Light Contribution stored in the Lighting Render Element;
- Indirect lighting by spawned rays stored in the GI Render Element;
- Material Opacity stored in the Alpha Render Element;
- Received caustics stored in the Caustics Render Element.
The Adjust UV tiling to match real-world size option:
- Works only in polygon selection mode;
- Works with UV texture maps only, as distortion can affect the render;
- Does not work with empty UV texture maps. Instances or replicators must be converted to mesh items.