Material] VrayDirt map.

All the examples are rendered using a VRayMtl with a VRayDirt Map in the Diffuse channel:

 

Example 1: Radius parameter

This parameters determines the amount of area (in units) where the VRayDirt effect is produced.

Notice that two of the object do not contact any other objects on their tops, so there is no dirt effect.

Example 2: Distribution parameter

This parameter will force the rays to gather closer. The effect is that the dirt area is being narrowed closer

to the contact edges.

Example 3: Falloff parameter

Example 4: Subdivisions parameter

Example 5: Ignore for GI / Consider same object only

1/ This check-box determines whether the dirt effect is going to be visiable during the GI calculation.

2/ Consider same object only - On - in this case the dirt will affect only the objects themselves,

without including contact surfaces and edges.

Example 6: Texmap radius / Invert normal

In the next example a bitmap is used in the texmap radius slot. Notice that the main radius parameter

still has effect - it determines the amout of area where the texmap radius bitmap would blend.

Invert normal parameter will change the direction of tracing the rays. When it is Off the rays are

being traced outside the surface, when On they are traced inside the surface.

Example 7: Biases

These parameters will bias the normals, so that the dirt effect is forced to some of the axis(es).