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Displacement mapping is a technique for adding detail to geometric objects without having to model it first. The concept is very similar to bump mapping. However, bump mapping is a shading effect that only changes the appearance of a surface, while displacement mapping actually modifies the surface.

The image slider on the right shows the effect of the Displacement mapping.

Creating Displacement:

||V-Ray Asset Editor|| > Create Asset > Geometries > Displacement

||V-Ray Asset Editor|| > Geometry > Displacement

Assigning Displacement:

||Appearance Manager|| > Materials tab > Add Displacement

Enabled – Turns on/off displacement.

Mode/Map – Specifies the mode in which the displacement is rendered:

Normal Displacement – Takes the original surface geometry and subdivides its triangles into smaller sub-triangles which are then displaced.
2D Displacement – Bases the displacement on a texture map that is known in advance. The displaced surface is rendered as a warped height-field based on that texture map. The actual raytracing of the displaced surface is done in texture space, and the result is mapped back into 3D space. The advantage of this method is that it preserves all the details in the displacement map. However, it requires that the object has valid UV coordinates. You cannot use this method for 3D procedural textures or other textures that use object or world coordinates.

Amount – Specifies the amount of displacement. A value of 0.0 means the object appears unchanged. Higher values produce a greater displacement effect. This value can also be negative, in which case the displacement pushes geometry inside the object.

Shift – Specifies a constant to be added to the displacement map values, effectively shifting the displaced surface up and down along the normals. This value can be either positive or negative. See the Shift example below.

Keep Continuity – When enabled, V-Ray tries to produce a connected surface. Use it when you get splits (usually around sharp edges) in the displaced geometry. See the Keep Continuity example below.

View Dependent – When enabled, the Edge Length parameter determines the maximum length of a sub-triangle edge, in pixels. A value of 1.0, for example, means that the longest edge of the resulting mesh is about 1 pixel long (when projected on the screen). When disabled, the Edge Length value is the maximum sub-triangle edge length in world units.

Edge Length – Determines the quality of the displacement. The behavior of this parameter depends on the View Dependent parameter above. Note that each triangle of the original mesh is divided into sub-triangles. More sub-triangles mean more detail in the displacement, slower rendering times and more RAM usage. Less sub-triangles mean less detail, faster rendering and less RAM. See the Edge Length example below.

Max Subdivs – Controls the maximum number of sub-triangles generated for every triangle of the original mesh. The maximum number of sub-triangles can be calculated by squaring this value. For example, a value of 256 means that at most 256 x 256 = 65536 sub-triangles are generated for any given original triangle. It is not a good idea to increase this value much higher than 256. If that's required, it will be better to tessellate the original mesh.

Resolution – Determines the resolution of the displacement texture used by V-Ray. If the texture map is a bitmap, it would be best to match this resolution to the size of the bitmap. For procedural 2d maps, the resolution is determined by the desired quality and detail in the displacement. Note that V-Ray also automatically generates a normal map based on the displacement map, to compensate for details not captured by the actual displaced surface.

Water Level – Turns on/off water level.

Level Height – Specifies a value below which the geometry is clipped. See the Height Level example below.