STEP-BY-STEP SETTING THE GLASS PARAMETERS

ONE CREATE A NEW MATERIAL

Open the Maxwell Render Material Editor and select Update to refresh the material preview. Click on the layer named BSDF to begin the process of creating the glass material. Change the reflectance 0 and reflectance 90 colours to pure black and change the transmittance colour to white. The preview will show a completely black material because the attenuation setting hasn’t been specified yet.

TWO SPECIFY ATTENUATION

Attenuation distance and Transmittance work together. You have to set the Transmittance colour higher than RGB 0 for the Attenuation distance to become active. If your Attenuation distance is very small (for example 1nm), the object will remain opaque because the light can only travel a very small distance into the object and will not come out on the other side. I have set the attenuation at 3cm in this instance.

THREE ND PARAMETER

The ND parameter determines the IOR (Index of Refraction) of the transparent material. The higher the index of refraction, the more the light bends as it enters the object, producing the typical distortions of things seen through it. Remember also that surface reflections are stronger with increasing ND. For this glass material, the ND has been set at 1.560.

FOUR ROUGHNESS AND FORCE FRESNEL

Finally, decrease the roughness setting to 0 and enable the Force Fresnel setting (to ensure that the result is physically correct). If the Force Fresnel parameter is enabled and the surface roughness is low (0 to around 15) then the Reflectance colours will not matter. The surface reflectance will instead be determined purely by the ND – and as we’ve mentioned, higher ND will produce stronger surface reflections.