motion blur TAB

Octane has a powerful and fast motion blur feature. In general, people do not prefer to render with native motion blur of any 3D software. Because Motion Blur increases the rendering time. This is usually done with 3rd party compositing softwares. And frankly, none of them have ever been able to capture the 3D motion blur quality (because it's real). So you can use Octane Motion Blur as long as you optimize your scene and render settings. Because it's fast. Now let's explain the options in Motion Blur Tab.

Important note: Octane has 2 different motion blur: Camera and Object Motion blur. You will see the camera motion blur when the camera is moving. Object motion blur is used when the object is animated. You can control the camera motion blur from the Octane Camera Tag and the Object motion blur from the Octane Object Tag. Detailed explanations for both will be found in this section.


camera motion blur

It is the type of motion blur you will use when the camera in your scene is moving. Let's take a look at the options now.

Info: Whether a camera or Object motion blur, the options you see in the picture below are global options for both situations.



ABOUT shutter speeds

To understand the Octane motion blur, let's look at the definition of "Shutter Speed" briefly: "In photographyshutter speed or exposure time is the length of time when the film or digital sensor inside the camera is exposed to light, also when camera's shutter is open when taking a photograph. The amount of light that reaches the film or image sensor is proportional to the exposure time" (Source: Wikipedia).

Shutter Speed determines the shutter opening and closing time, which is until the image is formed. The quality of moving images is dependent on Shutter Speed. The shutter speed can also determine the sharpness of the image which is also affects the amount of light reaching the camera sensor. If shutter speed is slow, blurred image occurs.

Shutter Speed values are expressed in proportions such as 16, 8, 4, 1, 1/4, 1/8, 1/16. As the number increases, your exposure increases. As the number decreases, you will have shorter exposure (like 1/15 or 1/500 of a second). "1/500" means the shutter opens and closes 500 times in a second. If you consider that eye blinking is 20 times in a minute, you can more easily understand how fast 1/500 is a shutter speed value.

There are many factors that affect Shutter Speed. However, we recommend that you browse the resources on the Web because it is very broad subject to explain here.




motion blur SETTINGS

Enable

Used to turn Motion Blur on and off.


Shutter (sec.)

Here you can adjust the Motion Blur amount in Octane. You can enter real camera values or a random value in this field. If you want to enter the actual value, you can adjust the shutter speed with a simple calculation. For example, if you want to make a shutter speed of 30 in 1 second, what you will do is divide 1 into 30; the result you get is the shutter speed value you will enter in Octane. In this case, 1/30 = 0.03.



time shift (sec.)

Used to shift the calculation frame of the motion blur. You can leave it at the default value.


m.blur caches (frames)

This feature determines how many frames will be cached when moving back and forth in Live Viewer. Because LV can only know the data in existing frames. Therefore, you can store the motion data in LV by entering the frame number to be cached in this field.


SHUTTER ALIGNMENT

It consists of 3 options: Before, Centered, After. In general, it specifies how the motion blur effect is calculated relative to the previous or next frames. For example, if there is a motion blur of 10 frames and you are at 20th frame; Before: Produces blur according to frames between 10-20, Center 15-25 and After 20-30.


disable camera m.blur

You can activate this feature if you want to see only the motion blur of the objects, but not the motion blur effect of the camera. It works effectively when both camera and objects are moving in the scene.



object motion blur

It is used to apply motion blur only to objects so the objects in your scene must be moving. Once you have selected the relevant object to use, you can assign "Octane Object Tag" to the object by going to the object manager's C4DOctane Tags. Now let's take a look at these options:



Object Motion blur

From here you can apply motion blur types to your object. There are four options: Disabled, Transform, Transform / Vertex, and Vertex Speed. Now let's explain these.

disabled

It is used to disable the motion blur effect of any object in the scene. Let's say you have 10 different objects and you want to disable a few of them. In that case, select the object you want to turn off the motion blur and disable it here. Simple.


Transform

You can use this option to apply motion blur to the PSR transformations of your object. It only functions at Position / Rotation / Scale values. For example if your object has deformation movement other than PSR then this option will not work. It is necessary to use the Transform / Vertex option to blur deformation-like movements. We will explain this in the next chapter. You can use the options in global camera motion blur to make adjustments. The options there are also used for object motion blur.



Transform/vertex

You can create motion blur based on both the transform and vertex movements of your object. According to vertex, motion blurring can be a complicated process. So in the following mini tutorial we will tell you how vertex blur works. In the tutorial, we will describe how to apply motion blur a certain part of a fast moving flag using vertex map. If you want the tutorial's scene, you can download it from the link below and check it out. Shading / texturing and rendering are not described in this one. These sections are outside the scope of this tutorial. However, the shading and rendering setups are ready in the scene we link to. You can use it as you like.

Download scene from here:


01- Create one plane object and modify its properties as shown in the following picture. Then press "C" to make the object editable.



02- Now we will make a cloth simulation to the object. First, switch to point mode when selecting an object and select the points on the left side of the plane object as you see in the picture below. We choose these points to fix the flag.  



03- When points are selected, right click on object manager and select "simulation tags / Cloth" from the menu. Go to the Cloth Tag and press the "Fix points set" button on the Dresser Tab. Now our flag is fixed.



04- Now increase the number of frames in the timeline for the cloth simulation as you wish. Go to the Cloth Tag and enter the values you see in the picture below into the relevant fields.

 



05- After finishing Simulation, go to the cache tab and cache it. Now we need to "PLA bake" the flag movement. So we can reach the vertex points, paint and create the vertex map. Let's make a PLA bake first. Press Shift+Alt+F3 when your flag object is selected. The Timeline window will open. While selecting an object, go to the "Functions" menu and select "Bake Objects". Make the settings you see in the image below in the opened window. When you press the "Ok" button, the Flag object will be baked. Now you can easily go back and forth in the timeline and see the animation without sim calculation. The bake process is very useful, but it has no return. So it is always recommended to work with backup.



06- After the simulation of the cloth and the bake process is finished, we can now create a vertex map. Switch to point mode, then press "Shift + C" and type "Paint" in the resulting box. Select "Paint Tool" from the drop down menu. You can start painting by selecting "Paint Mode / Vertex Map" from the Paint tool options. You can paint it as you see in the picture below. All you need to use "add" and "Smooth" alternately from Mode while you are painting. So you can create a smooth transition of the painting areas.



07- Now let's make "Octane Object Tag" and "Octane Camera Tag" setup. After painting, exit point mode and return to object mode. When Flag object is selected, right click to "C4d Octane Tags" and select "Octane Object Tag" from the menu. From there, go to Motion Blur Tab and select "Transform / Vertex" from "Object Motion Blur".



08 - Create an Octane Camera on the scene and change the Motion blur settings on the Octane Camera Tag as you see in the picture below.



09- Now run Live Viewer. As you can see in the picture below, the vertices we paint are blurred by the Transform / Vertex option. If you could select only Transform, you could not see the blur effect because there is no real transform value in the flag object. So you could not get the blur effect because there would not be Position / Rotation / Scale data. What is important here is how you define vertex maps and points. You can apply this method to whole flag instead of a part of the flag. It is important to realize that the vertex movement is very different from the PSR movement.




vertex SPeed

With this option you can create motion blur according to the movement speed of vertices. This option works very efficiently in Fluid / Liquid simulations. Basically a vertex map consisting of 3 separate axes is required. By defining these vertex maps to Octane, you can give motion blur to the flow of fluids. Now let's explain this situation again with the help of a tutorial. You can download the scene from the link below. Because you need this scene to follow this tutorial.

In the Tutorial we will add motion blur to the liquid (for example milk) poured onto a chocolate bar. We will keep the simulation fairly simple because entering the endless simulation details is beyond the scope of this tutorial. For fluid simulation we will use Next Limit's Real Flow for Cinema 4D V2.5 plugin. In this case, make sure you have installed the Realflow Plugin before opening the scene. You can buy plugin from here

Dowload the scene from here


01- First download and open the scene we link to above. Camera angle and everything else is ready, so we will not deal with their setup. Now go to Reaflow from the Cinema 4D menus and select "Scene". Once selected, the Realflow system will appear in the object manager.



02- Now create an "Emitter" and a "Fluid" object. For Emitter go to the RealFlow menu and select "Circle" from "Emitters". For Fluid object, select "Fluid" from the menu. Drag and drop the Emitter and Fluid objects into the relevant sections of the RealFlow system and make settings for both objects as shown in the image below.



03- Go to the Coord. Tab for the position of the emitter. Enter the following values: "P.X: 0 / P.Y: 308.896 / P.Z: 0" and "RB: -51.288". Once you have entered the values, the Emitter position should look like the picture below. If not, you can manually place it directly above the chocolate bar. In this angle, we will spray the particles.



04- Let's do the setup for the chocolate bar. Right-click while selecting object in Object manager and select Realflow Tags / Collider from the menu. With this tag, the particles falling on the chocolate will interact with the object.



05- Now let's add 2 daemon objects for the liquid spill action. Go to the menu and select "Gravity" and "Noise Field" from the Daemon Section. Leave the Setups as default for now. If it's not automatically linked when creating these 2 objects, drag and drop the related objects into the fields you see in the picture below.



06- Press the play button to test the simulation. As you can see, the particles that spill from the top quickly spread and interact with the chocolate bar. Now it's time to mesh these particles. Go back to the RealFlow menu and choose "Mesher" this time. Make the setup as you see in the picture below.



07- Now let's add motion blur to this spilled liquid. To do this, right click on the "Mesher" object and select "C4doctane Tags / Octane Object Tag" from the pop-up menu. From Tag options, go to the motion blur tab and select the Vertex Speed. Three separate tags are required for vertex speed. These tags are automatically created during Mesher object creation in realflow. These tags are 3-axis vertex map tags. Now drag and drop these tags into the vertex speed slots in the motion blur section. Make sure you select the correct tags.  



08- If you have done everything right, you will get a result similar to the following picture. As you can see, there is a motion blur that flows through the velocity vertex tags we define. The important thing here is the vertex map tags consisting of 3 separate axes. Realflow automatically generates these tags during the mesher operation. Other simulation software/plugins also have these vertex tags. You can do the same in Houdini or Xparticles 4.