Blend Material

V-Ray Blend Material can be used to layer several V-Ray-compatible materials in an efficient manner. It can be used to create complex materials like car paints, human skin (when Fast SSS2 material is used as a base material) etc.  

You can use the Material Select render element to split the different sub-materials of the Blend Material into different render elements.  

V-Ray Blend Material takes a base material and applies other materials (coatings) on top of it. This works like a stack, where each coat material blends between its own shading and that of the materials below it in the stack.

||V-Ray|| > Blend Material

||Create|| > V-Ray > Blend Material (disabled Separate menu for V-Ray materials)

Base Material – The base material, over which other materials are layered. If this is not specified, the base material is assumed to be a perfectly transparent material.

Mode – Select how the V-Ray Blend Material behaves: like a multi-layered Additive material or as Energy Conserving. Selecting the Additive Mode would often result in a physically incorrect material (e.g. a material that reflects more light than falls on it). It is not recommended to use this option, unless you know what you are doing.

Add – Adds a new coat layer.

Clear – Clears all coat layers.

Enabled – Enables the layer. When disabled, the layer is not calculated in the Blend Material during rendering.

Move Up – Moves the layer with one position up in the stack.

Move Down – Moves the layer with one position down in the stack.

Remove – Removes only the selected layer.

Material – Specifies materials to use as coatings.

Blend Amount – Specifies how much of the final result is contributed by the corresponding coating material, and the rest of the materials below it. If the Blend amount is white, the final result is comprised of the coat material only, and other materials below it are blocked. If the Blend amount is black, a coat material has no effect on the final result. This parameter can also be controlled by a texture map.

Opacity –  Defines the strength of the layer.

Transparency – Specifies how transparent the Blend Material is. Black makes the material fully opaque and white makes it fully transparent. A texture map can also be used here.

Texture – Specifies a texture file to be used for the opacity.

Mix Strength – Specifies a blend amount for the texture map.

MATERIAL ID

Material Id Enabled – Enables the use of Material ID.

Material ID – The color used by the Material ID render element. You can also use a shader here.

Multimatte ID – The integer ID of the material to be used by the Multi Matte render element.

ROUND EDGES

Round Edges Enabled –  Enables the round edges effect which uses bump mapping to smooth out the edges of the geometry during render time.

Radius – Specify a radius (in world units) for the round edges effect. Since the actual geometry is not being changed and only the normals of the faces are affected, large values may produce undesirable effects.

Consider Same Object Only – When enabled, the rounded corners are produced only along edges that belong to the object which has the attribute applied. When disabled, rounded corners are also produced along edges formed when the object with the attribute intersects other objects in the scene. 

Corners – Choose which edges are considered in the calculation. Possible options are:

Covex and Concave – Considers all edges. 
Convex Only – Only applies Round Edges effect to edges with convex angles. 
Concave Only – Only applies Round Edges effect to edges with concave angles.