This page provides information on the Default displacement rollout in the GPU Settings tab.
Overview
The settings in this rollout control the displacement of objects with displacement materials that do not have a VRayDisplacementMod modifier applied.
UI Path: ||Render Setup window|| > Settings tab > Default Displacement rollout (Renderer set to V-Ray GPU)
Parameters
Override Max's – When enabled, V-Ray renders objects with displacement materials using its own internal microtriangle displacement. When disabled, the objects are rendered with the standard 3ds Max displacement.
Edge length – The maximum length of a subtriangle edge after subdivision. This affects the degree of subdivision before displacement, which in turn affects the quality of the displacement itself. Each triangle of the original mesh is subdivided into a number of subtriangles. More subtriangles mean more detail in the displacement, slower rendering times and more memory usage. Less subtriangles mean less detail, faster rendering and less memory used. Units used for this parameter depend on the View-dependent parameter.
In GPU mode where Cache Normals is always enabled for Subdivision type of displacement, lowering the Edge length or increasing the Max subdivs helps to achieve results more closely in line with CPU mode.
View-dependent – Specifies whether Edge length is expressed in pixels or world units. When this option is enabled, the Edge length value determines the maximum length of a subtriangle edge in pixels, and a value of 1.0 means that the longest edge of each subtriangle is about one pixel long when projected on the screen. When this option is disabled, Edge length is the maximum subtriangle edge length in world units.
Relative to bbox – When enabled, the displacement height is based on the bounding box of the objects, the way 3ds Max performs displacement by default. When this option is disabled, displacement height is expressed in generic world units where white areas in the displacement map correspond to a displacement of 1 generic unit. You can use the Amount parameter to increase or decrease displacement amount.
Amount – A scaling parameter for the default displacement. Values larger than 1.0 increase the displacement height, while values lower than 1.0 reduce it.
Tight bounds – When enabled, V-Ray tries to compute the exact bounding volume of the displaced triangles from the original mesh, which requires presampling of the displacement texture. Presampling takes more time if there are many variations between full black and white, but is faster if the texture has large black or white areas. If presampling takes too long, try disabling this option. When this option is disabled V-Ray assumes worst-case bounding volumes, and does not presample the texture.
Notes
- The default displacement amount is based on the bounding box of an object. Therefore, it is not a good choice for deforming objects. In that case, either disable the Relative to bbox option or apply a VRayDisplacementMod modifier, which supports a constant displacement amount.