1) Connect a displacement map to the Displacement Shader input of the Shading Group Node.
2) Multiply the value to set the displacement amount.
3) Control Displacement Settings globally through VRay Render Settings: Edge Length:
The minimum size in pixels for new created edges.
Lower values will create more detailed geometry but cost more memory.
Per Object Displacement with more controls:
1) Add a VRay Displacement node to the object (See images).
2) Connect Displacement Map
3) For more control, and Local displacement quality settings,
In the Attributes Editor, Add VRay Displacement Control and VRay Subdivision and Displacement Quality attributes to the object (See images).
These are the steps to activate Cycles Render new experimental MTD feature (Micro Triangle Displacement)
Cycles Render settings:
Set ‘Feature Set’ to Experimental.
Apply a Subdivision Surface modifier and set it to Adaptive mode.
* Adaptive Mode is only available if the modifier has no other modifiers below it.
Set the ‘Dicing Scale’ attribute in pixels to set the displacement accuracy
* Lower numbers will result in greater details and more memory usage
Material Cycles settings:
Set Displacement to ‘True’ or ‘Both’.
* Setting it to Both will automatically use the same height map texture data to drive surface normals (bump) and create a consistent effect
Cycles material node:
Connect a texture to the Displacement input.
White color will displaced to a height of 0.1 units (10cm) by default, manipulate the texture data using math nodes to achieved desired height and offset.
Cycles Geometry settings:
For more accuracy reduce the Subdivision pixel rates And increase the maximum subdivisions.
There is currently conflict between Adaptive Subdivision and Tangent Space Normal Maps that renders objects completely black.
A solution that is proposed at various discussions is to simply use Object Space mode in the Normal Map node.
I’m not sure how good is this workaround for non flat surfaces.. https://developer.blender.org/T49159
When using a procedural fractal texture as a Displacement map, Shaders that are dependent on surface angle may significantly change their appearance in different rendering resolutions because the texture provides more and more detail for the displacement and that changes the nature of the geometry.
The base mesh for the Displacement should be well Subdivided prior to the adaptive Subdivision in order to avoid polygon edges appearing.