Please note that this documentation space offers information for V-Ray 3.6! For most up-to-date documentation, refer to V-Ray Next for Modo help.

This page provides information on the V-Ray Car Paint Material.

 

Page Contents

 

Overview


The V-Ray Car Paint Material material is a material that simulates a metallic car paint. It is a complex material with four layers: a base diffuse layer, a base glossy layer, metallic flakes layer, and clear coat layer. The material allows the adjustment of each of these layers separately.

 

 


 

UI Path: |Shading viewport| > Shader Tree > Add Layer button > V-Ray Materials > V-Ray Car Paint

 

Base Parameters





Base Color – The diffuse color for the base layer.

Base Reflection – The reflectivity of the base layer. The reflection color itself is the same as the Base color.

Base Glossiness – Reflection glossiness for the base layer.

Base Trace Reflection – Toggle reflections for base layer.

Base Bump Color – Specifies the bump/normal map that is going to be used.

Base Bump Amount – A multiplier for the bump/normal effect.

Base Bump Type – Specifies whether a bump map or a normal map effect will be added to the base material. 

Bump map
Normal map in tangent space
Normal map in objectspace
Normal map in screen space
Normal map in worldspace

 

Flakes Parameters





Flake Color – The color of the metal flakes.

Flake Glossiness – The glossiness of the metal flakes. It is not recommended to set this above 0.9 as it may produce artifacts.

Flake Orientation – Controls the orientation of the flakes relative to the surface normal. When this is 0.0, all flakes are perfectly aligned with the surface. When it is 1.0, the flakes are rotated completely randomly with respect to the normal. Values above 0.5 are not recommended as they can produce artifacts. For more information, see the Flake Orientation example below.

Flake Density – The density (number of flakes) for a certain area. Lower values produce less flakes and higher values produce more flakes. Set this to 0.0 to produce a material without flakes. For more information, see the Flake Density Parameter example below.

Flake Scale – Scales the entire flake structure. For more information, see the Flake Scale Parameter example below.

Flake Size – The size of the flakes relative to the distance between them. Higher values produce bigger flakes and lower values produce smaller flakes. For more information, see the Flake Size Parameter example below.

Flake Map Size – Internally the material creates several bitmaps to store the generated flakes. This parameter determines the size of the bitmaps. Lower values reduce RAM usage, but may produce noticeable tiling in the flake structure. Higher values require more RAM, but tiling is reduced. Be careful when using the Directional filtering method, as it may quickly take up gigabytes of RAM for larger map sizes. For more information, see the Antialiasing Filters example below.

Flake Filtering Mode – Determines the way the flakes are filtered. Filtering is extremely important to reduce the work required to produce a clean image. The possible values are:

Simple – This method is faster and uses less RAM but is less accurate. It averages the orientation of the flakes together, which may alter the appearance of the material when viewed from a distance.
Directional
– This method is slightly slower and uses more RAM, but is more accurate. It groups the flakes based on their orientation before performing the filtering, so that the material appearance is preserved.

For more information, see the Flake Filtering Parameter example below.

Flake Seed – The random seed for the flakes. Changing this produces different flake patterns.

Mapping Type – Specifies the method for mapping the flakes. The possible values are:

Explicit mapping channel – The flakes are mapped using the specified channel.
Triplanar projection in object space
 – The material automatically computes mapping coordinates in object space based on the surface normals.

Flake map channel – The mapping channel for the flakes when the Flake mapping type is set to Explicit mapping channel.

Flake trace reflections – Toggle reflections for flake layer.


Example: The Flake Orientation

 

This set of images demonstrate the effect of the Flake orientation parameter. Note how lower values produce flakes more aligned with the surface normal, so that light is reflected more uniformly. Higher values produce more random flakes leading to more variation in the flake illumination.

 

 


Flake orientation: 0.0

 


Flake orientation: 0.1

 


Flake orientation: 0.4

 

 

 

 


Example: The Flake Density Parameter

 

This set of images shows the effect of the Flake density parameter. Note how larger values produce more flakes, but do not change the flake size.

 

 


Flake density: 0.5

 


Flake density: 1.0

 


Flake density: 2.0

 

 

 

 


Example: The Flake Scale Parameter


This set of images demonstrate the effect of the Flake scale parameter. Note how lower values scale the entire flake structure.

 

 


Flake scale: 0.008

 


Flake scale: 0.01

 


Flake scale: 0.02

 

 

 

 


Example: The Flake Size Parameter


This set of images shows the effect of the Flake size parameter. Note how larger values make the individual flakes larger, but do not change their count.


 


Flake size: 0.3

 


Flake size: 1.0

 


Flake size: 2.0

 

 

 

 


Example: The Flake Filtering Parameter


This example shows the effect of the Flake filtering parameter.

 


No filtering and no antialiasing; the result is very noisy because of the small flake size.

 


No filtering, Adaptive DMC antialiasing. The result is accurate, but very slow since a lot of AA samples are required to antialias the flakes.

 


Flake filtering
set to Simple , no antialiasing. The filtering greatly reduces the noise, but alters the appearance of the material.

 


Flake filtering
set to Directional , no antialiasing. The noise is reduced and the material appearance is correctly preserved.

 

 

 


Example: Antialiasing Filters


Here is an example briefly demonstrating the effect of different antialiasing filters on the final result.

 


Simple filtering
Flake map size
is 256 .
Flake maps take less
than 1 MB
.

 


Simple filtering
Flake map size is 512 .
Flake maps take between
1 and 2 MB
.

 


Simple filtering
Flake map size is 1024 .
Flake maps take 5 MB .

 


Simple filtering
Flake map size is 2048
Flake maps take 21 MB .

 


Directional filtering
Flake map size is 256 .
Flake maps take 10 MB .

 


Directional filtering
Flake map size is 512 .
Flake maps take 40 MB .

 


Directional filtering
Flake map size is 1024 .
Flake maps take 161 MB .

 


Directional filtering
Flake map size
is 2048 .
Flake maps take 645 MB .

 

 

Note that rendering with a particular filter is not the same as rendering without a filter and then blurring the image in a post-processing program like Adobe Photoshop. Filters are applied on a sub-pixel level, over the individual sub-pixel samples. Therefore, applying the filter at render time produces a much more accurate and subtle result than applying it as a post effect.

The Adaptive image sampler was used for the images above, with Min/Max rate of 1/24.

 

Coat Parameters





Coat Color – The color of the coat layer.

Coat Strength – The strength of the coat reflections when the surface is viewed directly from the front.

Coat Glossiness – Glossiness of the coat reflections.

Coat Trace Reflections – Toggle reflections for coat layer.

Coat Bump Color – A slot for the bump or normal map.

Coat Bump Amount – A multiplier for the bump or normal map.

Coat Bump (Map) Type – Allows you to choose between several types of Normal Maps and Bump map.

 

Options





Trace reflections – When disabled, reflections from the different layers are not traced.

Trace Depth – The number of times a ray can be reflected.

Double sided – When enabled, the material is double-sided.

Subdivs – Determines the amount of samples for the glossy reflections of the different layers. Note that this parameter is available for changing only when Use Local Subdivs is enabled in the DMC Sampler Settings.

Cutoff Threshold – Cutoff threshold for the reflections of the different layers.

 

Environment override





Use Environment Override – When enabled, allows the user to specify an environment only for this material.

Environment Override – A color or texture that will be used as an environment for the material.

Environment Priority – This specifies how to determine the environment to use if a reflected or refracted ray goes through several materials each of which has an environment override.

 

V-Ray Mtl Common


The V-Ray Mtl Common tab includes rollouts like Layer and Bump and Displacement, which include settings that are general among many V-Ray (and Modo) Materials. For more details, please see the Common V-Ray Material Attributes page.

 

Notes


  • The V-Ray Car Paint Material material needs to precalculate several textures related to the flakes. Depending on the Flake map size parameter, this may take a few seconds. When using the swatch preview, this may lead to slight delays between changing a parameter and the update of the material swatch.