Join Donovan Keith for an in-depth discussion in this video Tweaking shutter speed and motion blur, part of Production Rendering Techniques in Cinema 4D.
Renders coming straight out of CINEMA 4D typically are very sharp, too sharp. And when you're looking at an animation, there is a distinct lack of what's called Motion Blur. So, your animations will often look very stroby. Objects will sometimes seem to jump from one part of the screen to the other without any real connection between those two points. And what I'm going to go over in this video is how to add motion blur to your renderings to make them more realistic and really just more visually appealing. What we have here is a windmill that's been inspired by the kinetECO logo, and we see that it's spinning probably because of wind.
If we stop the animation at any point, what we'll see is that these blades are not perfectly crisp. They are blurred because of their motion, and they are blurred in the direction that they are moving. So, let's go into CINEMA 4D and add this effect. When you render in your Editor View, you simply will not see motion blur. To see any sort of motion blur, you need to render to your Picture Viewer. What we're going to notice, though, is that we don't see any when we first render out. And that's because we haven't turned it on yet. So, go into your Render Settings and change your Renderer from the Standard Renderer to the Physical Renderer.
Now, there are other ways of adding motion blur to your scene, but we want to stick with the Physical Renderer for now. And in the Physical Renderer, we want to turn on the Motion Blur option. We just click on the check mark there, and the default settings usually give you a pretty good result. Again, we're going to have to render to the Picture Viewer. So, you can hit Shift+R to do that. And we'll see now that there is a slight blur on our blades as they rotate. To adjust the strength of this blur, there are some settings. Go into your Camera Object and click on the Physical tab.
Inside of here, we have the Shutter Speed option. Now I'm going to go into a different scene to demonstrate this. In this scene, what I've got is a very simple animation of a cylinder that is being rotating about 45 degrees a frame. I'm going to go to my middle frame here, and let's take a look at how this looks at different shutter speeds. I'm going to choose 1/250 of a second first by clicking on this Camera and rendering to my Picture Viewer. We see something that looks a little bit blurry.
If I choose No Blur here, which is an incredibly fast 1/1000 of a second and render, we'll see something that looks pretty crisp. There is still a little bit of blur in the edge, because the object is moving within that 1/1000 of a second, but it's not too significant. Now, if we go to something like 1 second for our shutter speed, a very long exposure and render to the Picture Viewer, then I see something like this, and we see the beginnings of an artifact, we see sort of what looks like a polygon outline.
And that's because our render settings aren't set to be quite high enough. So, we go into our Render Settings and go the Physical tab, you'll see the Motion Subdivisions option right here, and that defines how many intermediate steps there are. And if we increase this number, to say 5, and we render again, we'll notice that our line gets a little bit cleaner. And at 6 it should be nice and round. Now, a 1-second exposure is not something that you're really going to see in a film or video, because video tends to operate at 30 frames per second, film at 24 frames per second, so really the slowest that you can get with video is 1/30 of a second and film 1/24 of a second.
So, when you are adjusting your Motion Blur settings by adjusting your Shutter Speed, make sure that you're staying within the bounds of what's possible. Now, there are other approaches to creating motion blur in CINEMA 4D, but for the best looking results, I really recommend using the Physical Renderer. However, when you're up against a wall, you might just have to use a post effect like real smart motion blur for After Effects. Whenever you can, make sure that you add motion blur to your scene. It adds that little extra bit of realism and takes some of the CG-ness away from your finished image.
- Modifying depth of field
- Animating rack focus
- Using blurry transparency to create frosted glass
- Understanding global illumination
- Setting up HDRI lighting
- Optimizing render sampling settings
- Preventing over-/underexposure with color mapping
- Using negative lights to selectively darken parts of scenes