From LuxRender Wiki
Compared to Microdisplacement, Loopsubdivision does its thing before any actual rendering has begun. Loop can be used to subdivide a mesh, apply displacement to a mesh or both.
- Subdivision Levels
- This setting controls the number of subdivisions that LuxRender will perform on the mesh before rendering. Loop is memory intensive so start with a low subdivision level and increase it if it doesn't give enough details. This depends on how low poly mesh you are subdividing.
- Normal smoothing
- This setting controls whether the normals should be set to smooth shading after subdivision or not. Note that pre-existing normals on the mesh will be discarded, so if you want a smooth-shaded mesh, use this option to re-smooth the subdivided mesh. Otherwise there will be no interpolated normals for the final mesh, resulting in it being completely flat shaded.
- Sharpen bounds
- This setting controls whether sharp corners should be kept sharp after subdivision or not.
- Normal split (preserve sharp edges)
- Splits edges at breaks in the shading normal. Used to preserve the sharp edges produced from the "split edge" command in some modelers.
- This setting allows you to select a grey scale image to be used as displacement map. Black is no displacement and white is full displacement as set by the Scale amount.
- This setting allows you to select the amount of displacement. A positive scale value results in displacement in same direction as the normals. Use a negative scale value to displace against the normals (into the mesh). Prior to LuxRender 1.2, displacement directions were reversed.
- This setting acts like a shrink/fatten modifier.
Here is an example with Loopsubdivision and displacement. The base mesh has 96 triangles and is subdivided with Loop 6 levels to give a resulting mesh of 393 216 triangles. Normal smoothing checked and Scale: 7cm.
Download example .blend file