General motion blur parameters
The motion blur tab controls the calculation of motion blur. These parameters are used when you render with a standard camera or VRayPhysicalCamera with motion blur enabled. Note that if you use the VRayPhysicalCamera in your scene, some of the parameters in this section are ignored.
On - turns motion blur on.
Disable for RR cameras - Setting this option on will disable camera Motion Blur for the Render Region. This is the default. If camera motion blur is enabled, the Render Region may produce unexpected results and render a different image than the interactive view. This is a known technical limitation.
Geometry samples - this determines the number of geometry segments used to approximate motion blur. Objects are assumed to move linearly between geometry samples. For fast rotating objects, you need to increase this to get correct motion blur. Note that more geometry samples increase the memory consumption, since more geometry copies are kept in memory.
Duration - specifies the duration, in frames, during which the camera shutter is open.
Subdivs - determines the quality of the motion blur. Lower values are computed faster, but produce more noise in the image. Higher values smooth out the noise, but take more time to render. Note that the quality of sampling also depends on the settings of the DMC sampler as well as on the chosen Image sampler.
Bias - this controls the bias of the motion blur effect. A value of 0.0 means that the light passes uniformly during the whole motion blur interval. Positive values mean that light is concentrated towards the end of the interval, while negative values concentrate light towards the beginning.
Interval center - specifies the middle of the motion blur interval with respect to the Softimage frame. A value of 0.5 means that the middle of the motion blur interval is halfway between the frames. A value of 0.0 means that the middle of the interval is at the exact frame position