Flakes Color – the color of the metal flakes.

Texture – here an image texture or shader can be defined.

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

Flakes 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.

Texture – here an image texture or shader can be defined.

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.

Flake Size – the size of the flakes relative to the distance between them. Higher values produce bigger flakes and lower values produce smaller flakes.

Flake Scale – scales the entire flake structure.

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.

Random Seed– random value to define placement of flakes on surface.

Flakes Filtering – this is a threshold below which reflections will not be traced. VRAYforC4D tries to estimate the contribution of reflections to the image, and if it is below this threshold, these effects are not computed. Do not set this to 0.0 as it may cause excessively long render times in some cases.

  • 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.

Map Type – specifies the method for mapping the flakes. The possible values are:

  • Explicit UVW channel – the flakes are mapped using the specified channel.
  • Triplanar from Object XYZ – the material automatically computes mapping coordinates in object space based on the surface normals.

Trace Reflections – when off, the flakes will only produce specular hilights, but no actual reflections will be traced.

Flake orientation is 0.0

Flake orientation is 0.1

Flake orientation is 0.3

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.

Example: The Flake Density Parameter

Flake density is 0.5

Flake density is 1.0

Flake density is 2.0

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.

Example: The Flake Scale Parameter

Flake scale is 0.005

Flake scale is 0.01

Flake scale is 0.02

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

Example: The Flake Size Parameter

Flake size is 0.5

Flake size is 1.0

Flake size is 2.0

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.

Example: 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.

This example shows the effect of the Flake filtering parameter.

Example: Antialiasing Filters

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

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

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

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

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

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

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

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

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

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 below, with Min/Max rate of -1/3 and the Rand option on.