9.5.2

704 • CHAPTER 13
RENDERING • RENDER SETTINGS • 705
Figure 1. Figure 2. Figure 3.
You can activate Scene Motion Blur (SMB) to simulate a camera panning swiftly.
Think carefully before using eld rendering and scene motion blur together,
since the eld effect is often nullied. Not only that, but the quality of the
automatic SMB antialiasing is better without elds and you’ll save render
time.
Samples
With SMB, intermediate images are calculated and overlapped in the corresponding frame with varying
brightness. Choose the number of intermediate images for each frame using this drop-down list. The
higher you set this value, the longer it takes to render.
If the motion is rapid, you may need to use a high setting to avoid a stroboscope effect (Figure 2).
If you use scene motion blur in your scene, you may be able to reduce the amount of antialiasing.
Stationary elements in the frame are antialiased perfectly, whereas moving elements are not
antialiased. Usually, objects in motion do not require antialiasing — consider a 16-times motion
blur where there are 16 intermediate frames; in this case, the missing antialiasing makes no visible
difference. You can, of course, add antialiasing, although with a motion blur of 9-times or higher it
is not necessary and does little other than increase the rendering time.
Strength
Denes the strength of the motion blur effect. The pictures in Figure 3 were rendered with 25-times
SMB with Strength set to (from left to right) 20%, 40%, 60%, 80% and 100%.
Dithering
You can use this option to dither the scene motion blur. This helps to avoid stroboscope effects and in
addition you can often use a lower SMB setting. However, the dithering may create slight noise. You
can reduce the memory requirements for rendering by disabling dithering (set the value to 0%).