Displacement Parameters Rollout (iray Renderer)

Contains controls for displacement and height (normal bump) mapping.

• Main Toolbar > Render Setup > Render Setup dialog > Assign Renderer rollout > Choose " NVIDIA iray" as the Production renderer. > Renderer panel > Displacement Parameters rollout
• Rendering menu > Render Setup > Render Setup dialog > Assign Renderer rollout > Choose "NVIDIA iray" as the Production renderer. > Renderer panel > Displacement Parameters rollut

Note: Both the mental ray renderer and the iray renderer use these displacement settings.

Max. Displace

Controls the maximum offset, in world units, that can be given to a vertex when displacing it. This value can affect the bounding box of an object. Default=6.096m (meters).

Large values of Max. Displace can affect rendering performance. On the other hand, if this value is too low and the renderer returns greater displacement values, the Render Message window displays warning messages to that effect. You can use these warnings to fine-tune the value of Max. Displace.

Tip: If displaced geometry appears to be “clipped,” try increasing the value of Maximum Displace.

Method group

• Length Calculates adaptive approximation of the displacement according to Edge Length criteria.

  View

  Defines the space for displacement. When View is on, the Edge Length specifies the length in pixels. When off, the Edge Length is specified in world space units. Default=on.

  Smoothing

  Turn off to have the renderer correctly render height maps. Height maps can be generated by Normal Bump mapping.

  When using only height maps in the scene, make sure this option is off. If some objects in the scene use height maps while others use standard displacement, apply smoothing on a per-object basis.

  When on, the renderer simply smooths the geometry using the interpolated normals, making the geometry look better. This result, however, cannot be used for height map displacement because smoothing affects geometry in a way that is incompatible with height mapping.

  Edge Length

  Defines the smallest potential edge length due to subdivision. The renderer stops subdividing an edge once it reaches this size. Default=2.0 pixels.

  Max Level

  Controls the extent to which the renderer can recursively subdivide each original mesh triangle for displacement. Each subdivision recursion potentially divides a single face into four smaller faces. Choose the value from the drop-down list. Range = 0 to 7. Default=6.

  For example, using the default value means that the renderer can subdivide each displaced mesh triangle into as many as 4,096 smaller triangles.

• Parametric Regularly subdivides each triangle of the surface. This is the fastest and the best option for scenes that are regular and mostly flat.

  Subdivision Level

  Specifies how many times each input triangle should be subdivided. Higher Subdivision Level values result in a higher triangle count. In fact, each input triangle is subdivided into 4^{Subdivision Level} triangles. Range = 0 to 10. Default = 5 (1024 triangles).

  There is an upper limit of 8 million triangles per object.