Autodesk 12812-051462-9011 User Guide 3 - Page 1039

WARNING Turning on Motion Blur for both cameras and shadows can cause shadows to shift position. To avoid this effect, turn on motion blur for cameras only. Rebuild (Do Not Re-Use Cache) When on, the renderer saves the recalculated shadow map (.zt) file on page 8177 to the file specified by the Browse button. Default=on. ■ Use File When on, the mental ray renderer either saves the shadow map to a ZT file, or loads an existing file. The state of Rebuild determines whether the ZT file is saved or loaded. This option is unavailable until you click the ellipsis button (see following) to provide a name for the ZT file. ■ ... [browse] Click to display a file selector dialog, which lets you specify a name for the shadow map ZT file and the folder where it is saved. ■ File name After you specify a shadow map file (see preceding), this field displays its name and path. ■ Delete File Click to delete the current ZT file. Displacement group 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 mental ray renderer correctly render height maps. Height maps can be generated by normal mapping; see Creating and Using Normal Bump Maps on page 6384. 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 (see mental ray Panel (Object Properties Dialog) on page 322). When on, mental ray simply smoothes 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 mental ray renderer stops subdividing an edge once it reaches this size. Default=2.0 pixels. 6294 | Chapter 20 Rendering