HOPS

Transparency Tex – Specifies the transparency of the material.

Reflect Exit color – If a ray has reached its maximum reflection depth, this color will be returned without tracing the ray further.

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

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

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

Environment Override – Controls the override color or texture used.

Csv Path –

Flakes Csv Path –

Base – Enables the following options:

Type - The checkbox allows the user to specify whether a bump map or a normal map effect will be added to the base material. 

 Bump – Normal bump map.

 Normal (Tangent) – Normal map in tangent space.

 Normal (Object) – Normal map in object space.

 Normal (Camera) – Normal map in camera space.

 Normal (World) – Normal map in world space.

 From Bump –  The map is applied as determined by map type itself.

 Explicit Normal –  Applies the map as an explicit normal.

Subdivs – Determines the amount of samples for the glossy reflections of the different layers. This parameter has effect only when the Use Local Subdivs option is enabled from the Global DMC Sampler Settings.

Trace Reflection – Allows you to enable or disable the tracing of reflection for that material.

Flakes – Enables the following options for the Flake Layer: 

Scale – Scales the entire flake structure.

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

Trace Reflection – Toggle reflections for the flake layer.

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

Coat – Enables Coat layer.

Subdivs – Controls the quality of glossy reflections. Lower values will render faster, but the result will be noisier. Higher values take longer, but produce smoother results.

Cutoff – This is a threshold below which reflections/refractions will not be traced. V-Ray tries to estimate the contribution of reflections/refractions 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.

Trace Reflections – If this is disabled, reflections will not be traced, even if the reflection color is greater than black. You can turn this off to produce only highlights. Note that when it is disabled, the diffuse color will not be dimmed by the reflection color.

Trace Depth – Represents the maximum number of bounces that will be computed for reflections and refractions. The individual material reflection/refraction depth settings are still considered, so long as they don't exceed the value specified here.

Dim Distance – Specifies the distance after which the reflection rays will not be traced.  

Distance – Specifies a distance after which the reflection rays will not be traced.

Falloff – A fall off radius for the dim distance. 

Reflect Exit Color – If a ray has reached its maximum reflection depth, this color will be returned without tracing the ray further.

Csv Color Filter – 

Affect Alpha – Allows the user to specify which channels will be affected by the reflection of the material.

Color only – The reflection will affect only the RGB channel of the final render.
Color+alpha – The material will transmit the alpha of the reflected objects instead of displaying an opaque alpha.
All channels – All channels and render elements will be affected by the reflections of the material.

Glossy As GI – Specifies on what occasions glossy rays will be treated as GI rays:

Never – Glossy rays are never treated as GI rays.
GI – (Default) Glossy rays will be treated as GI rays only when GI is being evaluated. This can speed up rendering of scenes with glossy reflections.
Always – Glossy rays are always treated as GI rays. A side effect is that the Secondary GI engine will be used for glossy rays. For example, if the primary engine is irradiance map and the secondary is light cache, the glossy rays will use light cache (which is a lot faster).

Back Side – When disabled, V-Ray calculates the reflections only for the front side of the objects. When enabled, V-Ray calculates the reflections for the back sides of the objects too.