Materials FAQ

The Arroway collection of materials and textures was always available since the early versions of Maxwell. For this new version, clients asked us to make sure the installation pack was lighter so they could download it faster, so we decided to remove the Arroway collection and a number of other textures. Of course, the collection is still available for clients on our website. 
However, we did leave one Arroway texture in the installation file so you can test it – the first wood material, named "boards-01". 

You can download the whole material collection from the Customer Portal (Download area), under "Additional Contents".

From a physical point of view, the index of refraction is not just a plain number; it is derived from a complex calculation to define the refractive index at one particular wavelength. This is the calculation: 
Refraction at a particular wavelength = Nd + K.i

The Nd represents the refractive index, which is the well-known concept of Index of Refraction we often use. The K is the extinction coefficient: the amount of absorption loss when an electromagnetic wave propagates through a material. This is usually confused with the Abbe, but it is not in fact related to this. K is related to the extinction of the wave.

The use of the K value is optional. It should be used when creating more accurate metals and you don't want to use an IOR file or an IOR file does not exist for that metal. To find the Nd and K values of common substances, please see the Luxpop site. In the wavelength box (nm) enter a wavelength of 589.

The improvements in the Maxwell Render version 2 material system allow you to create better, more complex, and faster materials. Version 1.x materials are compatible with version 2, but a small number of version 1.x materials (and therefore scenes) may not look entirely correct. We recommend to re-do as many version 1.x materials in version 2 as possible to make them into materials of a far superior quality. 

The only materials that can present difficulties are SSS materials and Clipmap materials.

The new SSS system in V2 is better integrated into the general BSDF structure, making it more intuitive and easier to configure. As the new SSS model is slightly different to the old one, your old SSS materials might appear slightly different when rendered in the new version.

To get them to look the same again, you will have to raise your Scattering Coefficient to a higher value.

The new stacked layer system allows you to create more complex materials in a more intuitive way.  Previously, you had to play with transmittance maps to get a simple Clipmap. Now, to create a Clipmap material, simply set up your material as usual, and apply the Clipmap in the Opacity/Mask map in the Layer Properties panel. See the Clipmaps page for more details.